Moses Ludel

Great, Megatron! Your truck deserves to be free of shudders... When the U-joint angles are different, opposing joint rotational forces work against each other. Envision the angled arc that each U-joint follows as it rotates. Since part of the joint "compresses" and the opposite side "expands" during each rotation, there is actually a speed-up and slow down over the arcs. The driveshaft/joint input and output speeds remain the same; the U-joint design compensates for speed variations during each rotation of the joint. Simply put, if the rear driveshaft's front U-joint angle differs from the rear U-joint angle, even if the two joints align properly in "phase", they have irregular speed-up/slow down patterns over their arcs of travel. So you get a vibration because the shaft is fighting itself end to end. Another cause for this vibration is when a splined driveshaft is assembled with the cross-joints misaligned. This is "out of phase" and a real cause of vibration. It can even tear apart the driveshaft since the speed-up and slow down over the U-joint arcs of travel run at different cycles. You mention power/torque, and that brings up another concern. A driveshaft loses torque capacity as the angle/slope of the shaft increases. When a vehicle gets "lifted", the typical 4x4 scenario, if the driveshaft slope increases, the torque capacity of that driveshaft diminishes. U-joint life suffers, and failure of joints is often common. Even when the U-joint angles match as they should (by shimming the pinion angle or mid-shaft bearing properly), the U-joint lifespan is shortened. This is strictly a function of U-joints: steeper angles make the joint weaker. One way many offset this risk is the use of a CV or double-Cardan joint at the transfer case output yoke and a single Cardan joint at the rear axle pinion yoke. The CV not only reduces the angle on each joint within the CV assembly, it also helps knock off the driveline slope factor considerably. Since the double-Cardan CV joint has "self-cancelling" angles between the two cross joints, the rear axle joint angle (a single Cardan cross joint) can be very close to straight when measured at static vehicle height—with axles weighted or on the ground. Actually, 0-degrees of U-joint angle is unacceptable for U-joint survival. When running a CV driveshaft, I set the rear axle pinion joint (single-Cardan) for 1.5- to 2-degrees angle with the vehicle at static curb height and weighted. This minor angle allows the joint's needle bearings to rotate in the bearing caps, which prevents them from starving for lube and also distributes the load uniformly over the needle bearing sets within the U-joint caps. Note: The 1.5- to 2.0 degree rear joint angle is achieved by rotating the axle housing to angle the pinion shaft and yoke upward. There is only one "downside" to doing this: Lubrication/fill of the differential is thwarted by the dropped fill plug height. Aftermarket differential covers for lifted trucks often have a relocated fill plug, higher on the cover to permit normal fill levels with the pinion angle rotated. The amount of rear axle rotation has little affect on chassis geometry or spring action. Many lift kits provide a tilting spacer block to restore U-joint angles. On installations that require use of spring-to-perch wedges to restore the rear U-joint angle, I use steel and not aluminum wedges. Steel will withstand more punishment and not pound out or loosen over time. Thanks for letting us know how this worked out, Megatron! Great to hear your Ram is back in top form... Moses

Paul...I'd cleave toward the Canadian readout of 7,297 pounds, still less than I expected. The tires are stock size and like my '05 before the change. You're running a lot of pressure when empty, so they have more than enough air. (Are you okay with running this kind of pressure empty, or do you drop down to door sticker settings?) Sounds like you're pulling good size trailers but not pushing "billboards" down the road as far as wind resistance goes; the tall 5th wheels are the billboards. Would like to hear if the gear ratios on the axles are other than 3.54:1. Glad you're into the pyrometer. When running aftermarket programming and these kinds of loads, you do need the EGT monitoring to keep a lid on the engine stresses. EGT is the best means for monitoring the load on a diesel. I need to get a pyrometer for the '05. Really would like the dyne results from the community college testing, how fortunate that you can use this dynamometer. Stock would make sense as a baseline. This is exciting, Paul! The 25 mpg is not out of reason for a 2WD empty with the correct gearing. If he drives like we do, for mileage, 25 is conceivable. I place great stock in the right gearing, the Cummins ISB engines are hypersensitive to rpm when it comes to fuel efficiency. Under commercial loads (to 50K GVCW, apparently a medium duty truck application, not my one-ton with a 48RE transmission, for sure!), Cummins would like to see the ISB engine running in the 2100-2400 rpm range. I wouldn't expect more than 17-18 mpg unloaded and 14 mpg pulling a 7,500# trailer at that rpm. When I push to 2100 rpm empty, which is actually my presumed torque peak with the Hypertech Max Energy programming, I can expect 19-20 mpg, depending upon terrain and wind. This last factor, wind, cannot be underestimated. I raised the truck 4" with a chassis lift and added oversized tires, which is clearly a red flag for fuel efficiency. These trucks are hardly aerodynamic to begin, and I asked for it with this move. Since all modifications to my truck were made simultaneously, there is no way to separate the impact of the lift and broader frontal area, i.e. increased wind resistance, from the rest of the changes. For that reason, I work with the known factors: 1) driving for efficiency is something I can control, 2) gearing is intended for a top speed of 69-70 mph if fuel efficiency is primary, 3) gearing (4.56:1 with 34.6"/35" tires) was picked to maintain the lifespan of the engine first, as a fuel mileage consideration second, and 4) I take full responsibility for the impact of the lift, tires, gearing and all the accessories added to the truck! This last point is an important qualifier. I can't complain about fuel mileage after doing all of these modifications intentionally. I'm in damage control mode at this point. Let's keep working on your mileage. I appreciate your approach and the information gathering that you're willing to do. We can work with these facts and find a sensible strategy. Thanks! Moses

When you find that your engine repair includes cylinder honing, apply this process properly. The optimal honing finish will have the right cross-hatch pattern with correct angles. If you're unsure of the right "look" or angles, look closely at the photo below, the magazine's cylinder barrel after machine honing at L.A. Sleeve Company: Hand honing will involve the correct diameter stone hone or flex hone ("glaze buster"). Your cross-hatch pattern will depend upon the right pressure and speed of the hone as you run it up and down in the cylinder. At our tools forum, you will find my comments on the two most common cylinder hones and their applications. Once you choose the correct hone and decide what you want the cylinder wall to look like when finished, clean the cylinder carefully and take measurements. If you're honing in an automotive engine bay with the head off and the rods and pistons removed, make sure to protect the crankshaft journals from honing debris. This debris is abrasive and will instantly damage new rod and main bearings! Wrapping the journals with clean shop rags is one method of protecting the crankshaft. I like to use a suitable honing oil. Some will use an actual machine shop honing oil. I like "Lube Guard Assembly Lubricant" for its lubricating and cleaning ability. As you hone, the cylinder must slough off abrasive from its pores. There is both the cylinder material and the hone material to consider here, each highly abrasive! When honing, I like to use a rhythmic pattern up and down in the cylinder, moving the hone uniformly and with the same speed and force over the full cylinder. In the day, my mentors recommended moving the hone "in slowly, out quickly", and that pattern is good, too. If you're unfamiliar with the speed of a hone, try a one-second-down, one-second-up kind of count that's easy to follow. I use a 1/2-inch hand drill motor with cross handles if possible to maintain center while honing. Note: For some motorcycle barrels, it might be practical to use a drill press and suitable holding fixture for the barrel. Simulate the honing equipment found in an automotive machine shop. You have good speed (usually adjustable on most presses) and alignment control. Set speed to your needs. Use plenty of lubricant while honing this way! With a stone hone, you can adjust the stone pressure against the wall and also choose a suitable stone grit. If you have no idea what grit, there are usually manufacturers' recommendations for each stone set type. These are general recommendations and reflect speed and pressure as well. Cylinder wall material can vary widely. Iron is often alloyed with nickel or even chromium and moly like L.A. Sleeve Company's "Moly 2000" liners. If in doubt, use a moderate grit, it may take longer but will not chew up a cylinder wall and require re-boring. Warning: Both automotive and motorcycle engines that have Nikasil bore plating require special honing with a diamond hone. Do not attempt to hone this material with a conventional stone hone or glaze-buster silicone flex hone. Sublet honing to a shop with appropriate equipment. A good approach when determining a cross-hatch pattern is to match the original cross-hatch that is evident at the top of the bore above the taper. This ledge or "ridge" is not affected by the piston ring travel and therefore should show a pattern that the engine manufacturer (or a machine shop rebuilder) has used. Note: This works fine for most honing jobs, although there are some very exotic OEM hone patterns like the late '80s to 1990 4.2L inline six AMC/Jeep engines. Jeep had a problem with ring seating (likely due to consumers having no idea how to "break-in" an engine by that era). AMC went to a radical "swept" hone pattern: course, irregular and circular—not the conventional "X" look of typical power honing. The simplest ways to have a new hone job go sour would be failure to thoroughly clean the cylinder of debris after honing and failure to sufficiently break-in or "seat" the new rings. I tested many Jeep and other 4x4 trucks for OFF-ROAD Magazine in the '80s to mid-'90s (Argus Publishers days) and also tested vehicles on behalf of the Portland Oregonian newspaper in the early '90s. I recall several tests involving vehicles with very low miles on the clock that were using/burning oil. The cause was previous testers running these engines too hard without consideration for break-in. I never reported the oil consumption in these vehicle evaluations; this was driver error, not a manufacturing defect. In particular, I recall a 1989 Jeep YJ Wrangler with a 4.2L carbureted inline six that used a quart of oil every 50 miles and also a TBI Chevrolet Silverado V-8 pickup that used a quart of motor oil every 300 miles. Each of these engines had rings that had not seated. I was able to reduce the oil burning dramatically during my test intervals by simply treating these near-new vehicles with consideration and allowing the rings to seat properly. If given enough time, I'm certain the oil consumption could have been overcome. Some practical considerations include selecting piston rings designed for a reasonable break-in period. Unless building an all-out racing engine with forged pistons, I avoid "chrome" rings. Moly rings work very well and respond quickly to a properly finished cylinder wall. Make sure your cylinder(s) is spotlessly clean before applying either a light engine oil or Lube Guard to the cylinder walls for both piston and ring insertion and the initial engine startup. A new oil pump and pickup screen is always wise for automotive engines during a rebuild. You have the oil pan down anyway, replace the pump. For domestic engines, I've always run a Melling "High Volume" replacement pump and screen. Cheap insurance policy for a long engine life. Note: On motorcycle engines, at least measure the oil pump rotor and pump gears, check the housing for pitting and damage. Make sure parts are within specification from the manufacturer. Replace parts as needed. I'd like to follow up this article by creating an HD video how-to on cylinder honing. I'll look for an iron motorcycle cylinder or an engine block in need of honing. It would be productive to share the "art" of cylinder honing in video! Moses

There are many times when a light engine rebuild is possible. If cylinder taper (wear toward the top of the piston ring travel and TDC) is negligible and the cylinder is still "round" in bore shape, honing can restore the cylinder(s) to get a good piston ring seal on new rings. This is the traditional "ring and valve job" overhaul procedure, where the piston(s) are reusable and the rings will be renewed after cleaning the ring grooves carefully with the correct tool. This is a precisely honed motorcycle cylinder from the magazine's Honda XR650R. L.A. Sleeve has achieved this true, perfect cross-hatch with the use of a power cylinder hone. Machine shops strive for this type of cross-hatch pattern. For more details, see the magazine's how-to HD video series on the top end rebuild of the XR650R engine. Whether to "hone" or "glaze bust" is a matter of wear and how true the cylinder measures. A three- or four-stone cylinder hone is capable of truing the bore and also creating a "cross-hatch" pattern desirable for good ring seating and seal. The cross-hatch is actually done precisely on a boring/honing machine when an engine or cylinder barrel gets reconditioned at a machine shop. When performed at the machine shop environment, actual angle or "degrees" of the cross-hatch intersect lines achieve a precise angle. This is controlled by the speed of the hone going up and down in the cylinder. At left is a flex hone or "glaze buster" with silicone balls mounted on stiff wire strands. Note that the hone must match the bore diameter of the cylinder being serviced. At center is a three-stone hone, known for better control of cylinder "round" and best for truing a cylinder. The stone package at right is "240 Grit", there are other grits for different honing finishes and speeds. If you choose to hone your cylinder and not sublet it to a machine shop, there are two distinct procedures: 1) honing with a stone hone and 2) breaking the glaze with a silicone ball glaze buster or "flex hone". Again, for precisely truing, the stone hone will be best. The silicone flex hone is a brush-like approach with pressure at each wire/ball. The glaze buster will follow the contour of a cylinder, and unless round and true, the result will be a glaze bust with cross-hatch that mimics the bore's shape. So, the best start is to measure the bore accurately for taper, out-of-round and size. If you can hone without making the cylinder oversized, the new rings and piston-to-wall gap will be within tolerance. Follow the manufacturer's recommendations for bore size, piston-to-wall clearance and the piston ring end gaps. Some like the flex hone for its ease of operation and relatively failsafe results. The stone hone, by contrast, must be used with caution and safely. There is the chance of breaking the stones or damaging the bore if you do not use the stone hone properly. See the forum on "General Repairs and Technical Tips" for details on the actual use of cylinder hones... Moses

Hi, Paul, welcome to the forum posts! To begin, the weight of your truck as equipped may be higher than 6600# when "empty". Is this over-the-scale weight or speculative? Our '05 Ram 3500 4WD Quad Cab SRW with short box was somewhere around 7,800# advertised curb weight. I've searched around the internet, and owners and information sites are throwing out figures of 7,100 to 8,100 pounds for stone stock vehicles, not being clear about completely empty or with passengers, fuel and so forth. I think we need to weigh our trucks, calculations for my truck are not actual scale weight. So, it would be wise to start with an accurate weight figure, and if you get one, please share. (We'll start using actual weights rather than advertised or speculative weights.) Also, I'd like to know the loaded truck weight whether it's in-bed campers or travel trailers in tow. I understand your frustration and am looking at your gearing. 3.54 is tall. Our truck had 3.73 gears when new, and without all of the add-on weight of accessories (lift kit, tires/wheels, Warn massive bumper and winch, Transfer Flow fuel tank for 75 gallons more fuel and so forth), we consistently got 22-24 mpg at 65-69 mph. At the conservative speeds you describe, running empty, I would achieve 24 mpg or a bare minimum of 23 mpg. If your tire size is the same as our '05 was stock, you should get better mileage than you're finding. Before commenting further about your tall gearing, I would like to know the tire diameter/size. 3.73 gearing seemed the magic number for our stock '05 tires at 65 mph, I caught an all-time best of 25 mpg with this arrangement on an empty run from the Reno Area to Portland, Oregon, holding speed to the 65 mph range. This was one time. Gearing is crucial. With the added equipment, weight and oversized tires, which essentially gave me gearing more like yours would be with stock tires, the fuel efficiency actually fell off. I thought optimistically that the overdriving effect of the 34.6" (advertised 35") tires would possibly improve mileage, and it didn't. Fuel mileage dropped dramatically, especially when trailer pulling. So this tells us something about the sensitivity of gearing. For the oversized tires, 4.10:1 gears would have restored the rpm and load to stock, but I wanted more pulling ability for the added weight and anticipated trailer pulling. There were no AAM gear sets available at the time between 4.10 and 4.56:1, and after pondering quite a bit, I opted for 4.56 gears. (You can see my install article and video at the magazine site, use the term 'AAM' in the Search Box.) I knew it would be necessary to hold speed to 65 mph for fuel efficiency, 69 is tops now, and my mileage varies accordingly: On flat ground, 65 mph is good for a consistent 21 mpg average with full tanks of fuel, passengers (2), luggage, empty bed and no trailer in tow. I've "squeezed" 23 mpg on flat I-80 runs with a tailwind at 65 mph. Step up to 69 and pay the price: Mileage is more like 20 mpg and drops to 19 in hilly country. Emphasis is that the truck could weigh over 9000 pounds going down the road "empty" as described. (Again, I need to get valid scale weight here!) 3.54 gearing is quite tall, however, your engine has a different torque peak speed (lower) than our '05 HO. Not sure what the dyne figures show for the "Smarty" reprogramming, if you have peak torque ratings from their testing, we can take that into account. I'm not comfortable spending others' money and time on gear changes unless there would be obvious gains. Please clarify your loaded weight (estimate at least), whether you are hauling in-bed campers or travel trailers, the tire size and the torque rating with the Smarty programming. Also, does the 'ScanGauge II' include a pyrometer? We'll discuss this further... Moses

Hi, Craig, and welcome to the forums! We're very pleased to have a new Jeep Wrangler member and happy help with your engine problem. One of the most popular and heavily trafficked articles at the 4WD Mechanix Magazine website is the piece I did on troubleshooting the 2.5L TBI Jeep four-cylinder engine. I suggest you read that for openers. I also did an in-depth exchange in the old "Q&A" column days with a Jeep Wrangler 2.5L TBI owner from Alaska. Here are the links to each piece: http://www.4wdmechanix.com/Tuning-and-Troubleshooting-the-2.5L-Jeep-TBI-Four.html http://www.4WDmechanix.com/Jeep-YJ-and-TJ-Wrangler-Fuel,-Spark-&-Emission-System.html [see the Q&A exchange titled, "Stumbling 2.5L TBI Four and a Long List of Solutions!" in this article format Q&A...Q&A is now all at these forums.] There is also the discussion right here at another 2.5L Jeep four-cylinder engine tuning topic: http://forums.4wdmechanix.com/topic/225-jeep-yj-wrangler-25l-tbi-troubleshooting/ Please let us know if this helps solve your issue. If not, we'll consider the next steps! Moses

Fantastic photos, Forman, absolutely suitable for framing!...This is what access to Nature is all about, and you captured it...Thanks for sharing...Feels like Spring! Moses

Yes, Belvedere...I have worked professionally at four-wheel alignment and taught these skills as well. The concern here is caster angle. As you raise the front end, the caster changes. Toe-set may change slightly, depending upon the lift method. Any change created by the Rough Country method of lifting your '07 Chevy Silverado truck would likely be minimal and easily corrected with a basic wheel alignment. I watched the Rough Country video (at your link), and this is a relatively simple way to lift the front end for "leveling" the truck. From what I could see of the lower control arm bump stop, you would not lose wheel travel, in fact, it looks like you would gain some travel, the thickness of the spacer provided. If there are any "downside" concerns, the steering tie-rod and CV joint angles are always a concern with IFS lifts. If the tie-rods slope down more at static vehicle height, there is a risk of "bump steer" or bump toe changes as the suspension rises and sets. If the half-shafts and CVs are on a greater slope, torque load and wear could be increased. The lift method that Rough Country uses should not impact either of these factors, as the design simple "drops" the lower control arm with a spacer to "lift" the chassis/frame height. Simple, this eliminates the risk of altered steering linkage angles or half-shaft angles.. If you do install this kit, take the usual precautions to be sure that no parts interfere or chafe after installation. This install in not much different than replacing ball joints or removing a half-shaft. If the spacers are a hard steel material or iron casting (please confirm for us) and the hardware is to grade and safe, you should have a relatively "stock" setup when done, with minimal changes to the front end geometry and the truck's engineering. Moses

Hi, Forman...I will start two new topics, one at the "General Repairs and Technical Tips", the other at the "The Right Tools and Equipment" forum. Expect details at each, including a comparison of hone types and the actual honing process for your motorcycle cylinder...I'll see if there's a cylinder around, this would be a nice HD video how-to! Watch for the two new topic posts...I'll get to them shortly, starting up the XR650R this morning after the upper engine rebuild and how-to video filming...Yeah! Moses

Just a suggestion on the manual, Belvedere. There are several used auto literature sources that would likely have an OE shop manual for your Silverado. Try these: http://www.faxonautoliterature.com/ http://www.rothautobooks.com/ There are others, too, this is a start. Faxon sells through Amazon as well, and Amazon might be another source. I'd like to see you get a genuine GM book, as you're detail oriented like me, Belvedere. You'll be much happier with a "first generation" view of the technology, and there should be a great descriptive about "AutoTrack" in the factory manual—from operation to rebuilding it! I poked around on other forums and found this interesting thread at the full-size GM truck forum. This may answer your question about the function of AutoTrack: http://www.gmfullsize.com/forum/showthread.php?t=24027. Scroll down the responses for details on the function and design elements. Moses

Exciting to have a "new" truck to consider, Belvedere! Suggestion: See if you can locate the factory owner's handbook or, better yet, the workshop manual. Used automotive book sources and eBay can often prove useful sources for this kind of literature. Though spendy, the OE manual is always my first consideration when a vehicle will be in our "fleet" for any length of time—and I bet you see it this way, too! RareCJ8 has his early-'2000s Silverado with monstrous 8.0L V-8 engine and Allison transmission, I'm expecting his comments on your truck soon! Moses

I am very pleased that the project is moving ahead and that Loctite 640 provided a sensible solution. Good stuff, well tested... Keep us posted, TTippetts! Moses

Forman, delighted you're back on the project...The current assembly stage can be confusing. From my experience, if the transfer case has never been rebuilt, and the shaft has the correct factory shim stack, you can simply clean and reuse the original shims with the new bearing set. Tolerances on bearings are so close with quality bearings that you will be simply "restoring" the original end play when using the factory shim thicknesses with the new bearing set. In case the unit has been rebuilt before, and if you did not check end-plays before disassembly, you might want to do a "dry assembly run" trial fit using an old bearing cone (assuming it has little tolerance wear!) with no seal in place. Once you're confident that you meet the end play I talk about later in the book's steps, you can replace the used outer output bearing cone with the new one, installed with the correct shim stack in place behind the bearing cone. During final assembly, install the seal before placing the U-joint yoke onto the shaft as described in the book. The yoke will pull the new bearing cone into position on the output shaft. Note: The rear output bearing cones "sandwich" the retainer's bearing cups. The shims set the shaft endplay by spacing the distance between these two output bearing cones. When you place the yoke on the shaft and tighten the nut, you compress these parts and can then read the actual shaft end play between the bearing cones and the cups. Shims determine this spacing. You can even do a trial fit of the output bearing shims using just the bare output shaft and the retainer held in a soft-jaw vise. Shaft shoulders seldom wear, so these tolerances should be right on when using the same case, end housings or retainer plates, shims and properly fitted clean parts. For trial fitting, I make dummy bearings from the old bearing(s) by sizing the I.D. of the old bearings with a drum sanding arbor disk or burr grinder, making the bearing a light finger-press fit over the shaft. (Size the bore uniformly.) This will make the trial fit of the shims much easier. You can slide the bearings on and off the output shaft without needing to drive the shaft through the outer bearing cone or use a puller or press to remove the inner bearing from the shaft. The inner output shaft bearing (new one) can be pressed in place on the shaft at any time, as the shims fit between the two bearing cones. For trial fitting, you can even create just one trial fit bearing—the outer one. You can perform trial fitting for end play without the seal in place. Note: The rear output shaft shims go between the two bearing cones, inboard of the outer bearing cone. To see the relationship of shims and end cap/bearing retainers, you'll find this parts schematic diagram helpful (courtesy of 4WD Hardware): Forman, here's an example of my dummy bearing approach and how to create dummy bearings: http://www.4wdmechanix.com/How-to-Dodge-Ram-Truck-Air-Filter-&-Fuel-Filter-Service.html. See steps 65-67 in the article. What you will discover is that old bearings without excess wear have very close tolerances to a new bearing. Obviously, if the bearing is damaged or excessively worn, this will not be true. Once you know that endplay is correct, you can place the rear output shim stack on the shaft between the two bearing cones, inboard of the outer bearing. Place the new outer bearing in position against its bearing cone (inboard of the seal). The bearing cone tapers should face toward each other. Install the seal in the output housing as described. The seal captures the outer bearing. Protect the seal from damage as you slide the end housing, outer bearing and seal over the output shaft. Use the U-joint yoke to pull the outer bearing cone into position on the shaft. Once the cone is seated, you should have the correct shaft endplay—verify it. Trust this helps, keep us posted! Moses

In my Chevrolet & GMC Light Truck Owner's Bible (Bentley Publishers), I devoted a short section to the upgrades needed when rebuilding a 700R4. 1986 has several improvements over the earlier design, there were others to come by 1989. If you do rebuild the '86 unit, check with a shop that knows the ins and outs of the 700R4 and can add the upgrade features during the build-up. This upgrading is well understood these days, as the unit has been around for 30 years now. A 1986 unit might hold up well if in good condition. Also, there is a torque converter lockup kit available from Painless for the 700R4 as a retrofit. You'll want to explore this further unless the Novak system employs a transmission controller for the 700R4. Street rodders often use the 700R4 with this simple aftermarket solution for the 4th gear lockup of the torque converter: http://www.amazon.com/Painless-60109-Transmission-Converter-Lock-Up/dp/B00062Z5OS. Please keep us informed if this becomes a plan. I'm interested in the outcome and driver satisfaction, fuel efficiency and such... Moses

Not a comforting discovery, it's worth comparing the original bearing fit in that bore. If the bearing bore is round and not scarfed from bearing creep or spinning, there is a solution. Loctite makes 640 Sleeve Retaining Compound. This product really works when applied correctly. Here are the PDF details about Loctite 640, its uses and proper application: https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/062262D5231164B0882571870000D85C/$File/640-EN.pdf Transmission bores that support bearings, like the AX15 intermediate plate, can lose a slight amount of tolerance over time. This intermediate plate is alloy, even more vulnerable than iron...Actual bearing creep or full-on "spinning" is not common on the AX15 transmissions and would quickly ruin the alloy plate. (The most likely causes of bearing creep or spin are excess loading or lack of lubrication.) The main shaft and countershaft bearings, though snug in their plate bores, are not an actual "press fit" into the intermediate plate. See my assembly of the AX15, steps 134-139 at: http://www.4wdmechanix.com/Moses-Ludel-Rebuilds-the-Jeep-AX-15-Transmission,-Part-2-Assembly-and-Final-Work.html Take into account that caged input shaft bearings are typically a finger press fit into the case bore of iron and alloy transmissions. Once in service, the bearing's outer race doesn't "spin" in the bore. Radial loads from the shaft encourage the caged balls to roll within the bearing...When I think of "spinning a bearing", the main bearings on an alloy air-cooled VW engine (with a split crankcase) come to mind. Loctite Red (271), originally called "Stud and Bearing Mount", targeted this engine's design flaw. Sounds like you do need some insurance here. Loctite 640 could be just what you want...If you find that the original bearing outer races also rotate with light hand force in the plate bores, Loctite 640 would be a sensible safeguard. This product is used commonly in industry on expensive machinery applications. Loctite recommends the use of its activator with the 640, and you need a clean bore and bearing outer surface for proper application. Apply 640 evenly, just a film. Install the bearings promptly, before the activated compound starts to cure. Loctite 640 is anaerobic and will cure with the parts in place. Loctite 640 will readily take up minute "clearance" between the outer surfaces of the bearings and the plate bores. Wipe off excess compound that squeezes out during fit up. Do not allow liquid compound to drip inside the bearings or other parts! From what you describe, Loctite 640 is the cost-effective fix for peace of mind... Moses

Thanks for the link, Rocket Doctor! The information is valuable to forum members contemplating this swap. I believe a 700R4 transmission would be best, you really can benefit from the overdrive. Your transmission core needs to be late 'eighties for maximum factory improvements. The 700R4 underwent a variety of upgrades through the '80s, each gain is essential. I'm on board with your 5.0L Ford idea despite my appreciation for Chevrolet V-8 engines. The distributor at the front, a low profile and light weight, an EFI/MPI 5.0L is appealing. Compact and potent, the H.O. 5.0L/302 Ford V-8 would be a good option for the unibody, lightweight Jeep XJ Cherokee. (For a heavier truck, however, I would pass on the 302 in favor of the 351W MPI V-8 with larger crankshaft journals.) The 302/5.0L has a following among hot rodders, and there are readily available wiring harnesses for swapping this engine into another chassis. The Ford 302 V-8 would fit the engine bay readily and look at "home" there. Either the GM or Ford swap material could mate up easily with the common splines and adapter input flange pattern of the NP231. Either swap could be done without a lot of fanfare. For 50-State emission legality, you would need to use a 1998 or newer engine and emission package. The options would be the LS for GM V-8s and either the Ford Mustang or Explorer for the 5.0L Ford V-8. The Explorer V-8 would be more accessible yet lower in horsepower and torque, a mild V-8 engine that could deliver decent fuel efficiency in an XJ. Your 8.25" rear axle is a good item, I have that in the '99 and set mine up with 4.10 gearing for the 33" tires. This axle is nice to work with and found in non-ABS XJs. Non-ABS seems to be the determinant over the Dana 35 rear axle. (Is yours non-ABS?) The Chrysler 8.25" rear axle should readily handle 250-275 horsepower in a light Jeep XJ Cherokee. Since the front axle only operates in 4WD, a Dana 30 could survive if the beam strength is up for the V-8 weight and torque. For the front axle, I would at least consider upgrade axle shafts and a 30-spline front differential. (Click on these two links to see my step-by-step articles on the Dana 30 rebuild and an 8.25" axle buildup for a Jeep XJ Cherokee.) Again, a light weight engine would be advised, focusing on aluminum heads and a "small-block" engine design. The GM Vortec 4.8L, a 5.3L LS or an HO Ford 302/5.0L each would be close to the weight of a 4.0L inline six with its iron block and cylinder head. Moses

A well maintained 4.0L is good for 200-250K miles, so that does take a while. I like the idea of the LS V-8, it's light in weight. Is this adapted to the AW4 or a manual AX15 or NV3550 transmission? How does the rest of the swap go? Engine mounts, radiator, hoses, wiring interface, etc. Do you need custom headers to clear the steering and chassis? What is the cost breakout? Presumably, you're on your own for the exhaust system... I'm very curious about your proposed swap. You would have an incredible power source and likely as good mileage as the 4.0L, which frankly, is not that great. We're in the 17-19 mpg range at best, and with overdrive and a 3,500 pound vehicle (ours is more like 3,800 with the lift and accessories), a smaller 4.8L Vortec or 5.3L LS V-8 XJ Cherokee should deliver decent mileage, maybe 20-21 mpg? Does the Novak kit work with any LS or Vortec V-8? Lots of potential here... Moses

Wow, what's happened to General Motors? We owned pre-IFS G.M. 4x4s that were bulletproof despite their quirks: 1) A '70 K10 pickup that could have used disc front brakes but otherwise worked flawlessly; 2) a '73 K10 SWB with SM465 and NP205 transfer case that was in my view the best full-size 1/2-ton 4x4 pickup ever built; 3) a '86 K2500 Chevrolet Suburban that needed nothing more than to get rid of the factory Gov-Loc rear differential; and 4) an '87 K2500 GMC Suburban that we bought with 160K miles, sold near 200K miles and heard most recently from the buyer that the truck has gone way beyond 300K miles and still runs well—Mobil 1 engine oil in the hard-worked 350 V-8! Your front end is a disappointment, I don't recall so much as a steering knuckle ball-joint or tie-rod end replacement on any of our G.M. beam front axle era front ends (primarily highway driven). As for the ABS module (which is a G.M./Kelsey-Hayes weak point), there is a positive solution. Our youngest son needed a module for an immaculate, very low mileage GMC Z71 Sonoma 4x4 (less than 40K original miles, timed out of warranty). We did the sticker shock pricing of the $600-$800 G.M. OEM replacement part fleecing and opted for a rebuilding solution from a company at Idaho. They know the weaknesses of every module, and these Kelsey-Hayes ABS units are well known there. Try Module Master at: http://www.modulemaster.com/. Note: For those interested, we discussed RareCJ8's T-case issue at: http://forums.4wdmechanix.com/topic/271-chevy-truck-transfer-case—pump-housing-damages-the-case/. Do you think JB Weld will hold on that worn T-case housing? Keep us posted... Moses

Welcome to the forums, Demerchant! I'm pleased to see your Ram delivering such good service and mileage. The weight involved is phenomenal, a real testimonial and chapter for the "Cummins story". As for maximum fuel efficiency and longevity of the engine, you're on the right track. Your K&N choice did come with the general concerns about gauze filters and adequate filtration. You drive highway, however, so dirt is not as much of an issue. The exhaust upgrade should be a plus, certainly no down side. If you continue to drive for economy and not to "see what the new exhaust and K&N air filter can do for performance" (well, maybe a little bit, but at the sacrifice of mileage when you do!), then these add-ons will be help with engine breathing and exhaust flow. Your 19-20 at 65 mph dead heading in overdrive sounds reasonable. The dually weighs a bit more than our '05 Ram 3500 SWR, and at 65 mph with 3.73 gearing, no load (also before the auxiliary fuel tank, massive winch/bumper, etc.) and stock tires, I could squeeze 23-plus mpg highway most of the time. I did accomplish a one-time high of 25 mpg on the highway, achieved by keeping the engine between 1600-1900 rpm faithfully over a 480 mile trip. Again, as Megatron and I have discussed, engine rpm is the key to fuel efficiency with any engine, and in particular the Cummins diesel. Our '05 HO reached peak torque (stone stock) at 1600 rpm, and driving between 1600-1900 was the sweet spot. If I pushed beyond the 1900 mark, fuel efficiency dropped considerably. When I added 1200 pounds of accessories and auxiliary fuel, the new dynamic, plus oversized diameter tires, required 4.56 gears. I'm now in the same league as your 4.10 gearing with your stock tire diameter. 69 mph is now 2100 rpm. 65 mph is a hair below 2000 rpm (1980-1993 rpm depending upon accuracy of the current tire diameter). 65 mph will return a consistent 21 mpg on highway cruise without a trailer, even at full fuel load (110 gallons) and the truck's weight hovering around 9,000 pounds. 69 mph means 20 mpg, often dipping to 19.8 mph with hilly or mountainous highway terrain. You're already driving for economy at 65 mph peak. If your tires are stock at around 31.9" diameter, with 4.10 gearing and 65 mph, I have the calculation at 1937 rpm in overdrive. (Does that sound right?) This is near the magic zone of 1600-1900 rpm for the later 2005 HO 5.9L ISB Cummins. As a comparison, the 2002 Cummins HO and standard engines reach stock peak torque by 1400 rpm. (Please confirm whether you have the 250 hp "standard" output engine. As I understand, the 2002 HO 305 hp engine was available only with a manual transmission, not your 47RE automatic.) Chrysler kept the lid on peak torque output with the 47RE transmission then turned the torque wick up on the 48RE with advertised horsepower at 325 and 610 lb-ft torque. (This is wonderful as long as the transmission can stand it! If we had not purchased our truck for multiple drivers, I would have opted for the 6-speed manual transmission.) Your 2002 Ram 3500's peak torque should be 460 lb-ft. (The HO with manual transmission rated 555 lb-ft in 2002.) Torque peak for both the 2002 standard and HO engines was at 1400 rpm. Our 2005 peaked its torque at 1600 rpm in stock tuning. An interesting footnote is how flexible the power can be on these Cummins diesel ISB engines. The 2002 HO's 555 lb-ft torque was quite a boost over the standard engine. Most of this difference is tuning or tune programming for these common rail, electronically fuel injected engines. When I decided to reprogram the '05 engine with a Hypertech Max Energy tune, the torque peak went up, achieved at 2100 rpm instead of 1600. This was a boon, as the engine now reaches peak torque at 68-69 mph and can deliver 20-plus mph on the highway even at that rpm and road speed. Torque peak is the key to fuel efficiency on these engines. Theoretically at least, your engine and fuel economy should be best between 1400-1800 rpm. A test for improved fuel efficiency might be to drop your cruise down to 1800 rpm (59 mph or so) and check the mileage. It should go up. Even slower, like 55 mph (1700 rpm), should deliver better mileage yet. This raises a practical consideration, though. Try confirming my suggestions for improving mileage on a flat stretch of road when you have the time and patience! Since there is also the sensible need to drive your truck at a reasonable pace, you may find that saving fuel is less important than getting to your destination in a reasonable timeframe. Note: According to Cummins' commercial site, the ISB commercial version of this engine should be run between 2100-2400 rpm for maximum efficiency (presumably including mileage). That's with commercial engine tuning/programming and intended loads to 50,000 GVCW. In my experience, that rpm would drop the mileage to the 17-18 mph range unloaded. With commercial tuning, however, it might help the heavy hauling tow mileage. There are few design differences between our engines. Hypertech taught me that tuning is everything: power, fuel efficiency, rpm for peak torque and peak horsepower. (Click here to see my full explanation of the re-programming approach.) A Max Energy program for your engine could make a difference in two ways: 1) an overall increase in performance and 2) bumping the peak torque rpm up, which would make your 2000 rpm cruise speed more viable for fuel efficiency. Understand that with any diesel engine, shoving more fuel and air into the engine increases power and often efficiency. I'm not clear about the number of miles or wear on your engine, and if you consider a re-program, do not alter your driving habits. Keep a lid on the engine exhaust temperature (EGT) under load! This last point is crucial. Hypertech assured me that its programming is "tow friendly". Your scenario would be the ultimate test, considering the loads you pull! I would not do a program change without installing an EGT meter. This should read exhaust temperature at the pre-turbo point if possible to assure an accurate read of actual exhaust temperatures. The turbo can cool exhaust readings considerably, so "post-turbo" probe installations can often be inaccurate. Warning: Use extreme care with drilling into the manifold pre-turbo: Metal filings and residue can destroy the turbo! Some use grease on the drill bits and tap. (Some argue this is not a good idea.) There are other techniques we can discuss if you install an EGT kit yourself. This sums up as two options for better fuel efficiency: 1) slow down the engine speed (either lower the vehicle's road speed or install a Gear Vendors overdrive for dead heading) and/or 2) do a tuning program change like the Hypertech with the proviso that you monitor your EGT as a safeguard. We're all on board with making the "million mile club" with these trucks...If you need an incentive, just price a new Ram/Cummins 3500 dually! As an anecdote from third parties, I was parked at a local fueling station alongside two Dodge Cummins trucks (an '04 and '05). The owners, a father and son, commented that our 5.9L models get much better fuel efficiency than the later 6.7L models. Better yet, and consistent with your plans, they had an '02 that ran to 600K miles before selling it, and the father insisted that the truck is still out there doing fine. It had a "chip", the type and brand not discussed, and according to these fellows, the mileage and performance were impressive. All three of their trucks were automatic transmission models, there was no discussion about transmission rebuilding. Let's keep this discussion going, Demerchant. The cost of fuel won't be going down any time soon! Moses

This sounds like detonation or “ping”. Detonation is the result of high compression and running lower octane fuel. If higher octane fuel remedied the problem, you may be able to run lower octane fuel by retarding the ignition timing. Spark timing changes are not done by moving the distributor on a Jeep 4.0L type ignition system. Spark curve and base timing changes are made by reprogramming the PCM with less spark advance. There is a provision (usually for up to 5-degrees spark retard) that can be re-programmed into the stock engine PCM/computer. This is done with either a factory DRB-III scan tool or an aftermarket scan tool that has the ability to correct base spark timing errors. Again, this is why I'm conservative about aftermarket programmers, as they usually target spark timing curves and advance the timing. You may get more power from one or the other programmer; however, you may also get severe and damaging detonation. This is why the Max Energy is a program that works for me: The stock compression engine will not detonate (ping) on 87-octane fuel. If I wanted to run 91-octane or higher, I could use the Max Energy high octane programming that came with the package. In your case, the engine needs higher octane fuel already due to the higher compression ratio. Moses

You're welcome, RareCJ8! Keep us posted, this hour meter idea makes great sense for a trail 4x4 vehicle. I gazed at hour meters for years as a heavy equipment operator, and the meters provided a valuable tool. Your lifeblood comment is real! s Synthetic oil provides a wider margin of oil protection; however, the oil filter needs attention. Many overlook the fact that an oil filter will bypass when clogged. Factory recommended 7,500 mile oil change intervals with tiny oil filters makes no sense at all. You cannot tell when the filter bypasses, so why run the risk? On our vehicles with Mobil 1, which I started using in the early 'nineties, the oil color approach worked well. Engines like the '87 Suburban K2500's 350 V-8 with TBI would easily go 10,000-12,000 miles (highway use) on a crankcase of Mobil 1 oil, with oil filter changes and top-off with Mobil 1 (replenishes the oil's additives in the process) each 3,000-3,500 miles. On the carbureted '86 K2500 Suburban with Federal emissions and an unrestricted carburetor, the oil change interval would be much sooner when we pulled a trailer—more like an oil change right after each hard tow, according to oil color! This, again, was determined by oil coloration, mocha to dark mocha being the limit. I also used deeper "truck" application oil filters for added surface area and capacity. (You could do this on small-block Chevy V-8s with the vertical oil filter design.) That method worked for me. Your hard trail use CJ8 Scrambler is a totally different scenario. The hour meter is the only sensible monitor. Moses

You replaced the factory "heavy duty auxiliary cooler" with a bigger cooler. There is the additional internal radiator transmission cooler, like on the magazine's 1999 Jeep XJ Cherokee 4.0L, that fits within the driver's side end tank of the radiator. This internal radiator cooler has been blocked off and by-passed on your '93 XJ Cherokee? This would not make a world of difference with the larger surface-to-air oil cooler you installed—unless your transmission or engine is having overheat problems. Moses

Establish a "rule of thumb". For a highway use model, I would use a 60 mph cruise speed baseline...3000/60 = 50 hours. How's that sound? Take into account usage and load. Rock crawling at 10 mph all summer would certainly warrant an oil change! Otherwise, you would be subjecting the engine to 300 hours of torture to accumulate "3000 miles", way too long between changes. If you're running synthetic oil, I've always changed Mobil 1 by the oil's coloration: mocha brown is time for a change. Change the oil filter and oil at 50 hours maximum. A new oil filter and top-off at 25 hours would make sense under severe driving conditions, with the full oil-and-filter change at no more than the 50 total hour point. Filters are cheap insurance, a case of Mopar OE type oil filters would be practical. Moses

You raise a concern, tom58c...When you installed the replacement cooler, did you eliminate any factory anti-drain back provisions in the lines or cooler? If you did, there may an issue of fluid draining back from the converter when parked. This condition usually occurs when you first start the engine and find that the converter takes time to charge before the vehicle will move. If your transmission's condition persists after initial startup, I would still evaluate whether the aftermarket cooler installation removed a factory means for keeping the torque converter charged with fluid. On the Chrysler (non-Aisin AW) RE/RH RWD transmissions, the anti-drain back valve is notorious for sticking either closed or open. Open, it allows fluid to drain back from the converter, which can starve the converter and even burn up the front pump bushing. See my comments in this article at the magazine: http://www.4wdmechanix.com/Survival-Upgrades-for-Jeep-and-Dodge-Ram-Automatic-Transmissions.html. This reference is strictly to foster some ideas around the cooler installation, the AW4 does not typically have the same issues as the Chrysler units. Glad to pursue this discussion further before you consider a complete rebuild. Let's look at in-chassis fixes first... Moses

What a great idea and premise, RareCJ8. Dirt motorcycles and off-road/heavy equipment are always serviced by "hours run". (No meter on a motorcycle, though, so this gets speculative. Industrial, construction and ag equipment does use an hour meter.) Your approach is accurate and, as you note, accounts for idling, rock crawling time and even the time you're onboard welding! If you hook to an ignition/run time lead that feeds only when the engine is running, you'll have a very accurate read on engine run time! Keep us posted... Moses