JohnF

Details on Rebuilding the Spicer Model 18 Jeep Transfer Case

37 posts in this topic

While waiting for the transmission parts to come in I disassembled the Transfer case. It went pretty easy. The only issue I had was when I removed the intermediate shaft I could not remove the intermediate gear as the book says I could. I had to wait until I slid the main shaft back a bit to remove the gear. The intermediate gear hit the side of the case. Not sure what I did wrong . I tried it in every gear.

 

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The intermediate gear is often supported on needle (loose) bearings with hard spacer washers.  (Check this link for a list of these parts, the 99-cents must be per roller!)  Typically there are 48 rollers.  Sometimes you'll find a pair of caged needle bearings instead of free needle rollers.  

 

With the needle rollers, the spacer washers can wedge against worn thrusts, causing a bind.  In this instance, the gear could get stuck in the case.  Look at the case, thrusts, bearings and the intermediate spacer.  If there's wear, was that your bind issue?  Worn thrusts are usually the culprit.

 

By the way, I like your work style—well organized and great parts layout!

 

Moses

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Moses,

moving the gear was not the issue, it moved freely. What happened is when I went to lift the gear out there was not enough clearance between the input shaft gear and the case for the larger gear to come out. I know its something I am missing because I see you do it in your book and others on the internet. If you look at the 1st photo of the tc the gear was hitting the very top (narrow part ) of the case.

John

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Ah, I see an issue when looking at the photos again...Did you remove the brake drum assembly with its companion flange and also the front output yoke first?  This may allow the lower shaft and gear set to move laterally slightly, which sounds like what you needed.  While the case looks like the casting has a bulky radius, this is not the problem.  (If it were, you could remove a slight amount of material with a die grinder and carbide bit; however, this should not be necessary.)  I believe you needed to remove the companion flange (U-joint) yokes and E-brake drum before the intermediate gear.

 

On assembly, the output flanges and brake drum get fitted last, after installing the intermediate gear and other gear sets with end caps, reversing the recommended disassembly sequence.  This should provide the space for the normal assembly procedure.  When setting the intermediate gear inside the case, needle bearings loaded, use a dummy shaft slightly smaller in diameter than the intermediate shaft and slightly shorter than the gear's width (just within the thrust washers).

 

You can partially assemble other parts before pulling the gear into position if you prefer.  When installing the intermediate shaft, the trick is to keep needle rollers in position (if not using caged bearings on the intermediate gear) when you install the shaft.  I load and coat the stacked needle rollers with a viscous chassis or wheel bearing grease to help hold them in place.

 

On your T86 cluster gear and this intermediate gear (or any other assembly using needle rollers), the rollers stay in place by "keystone effect".  If the bore is concentric and close to tolerance, needle rollers in good condition (not worn in diameter) should stay in place one you insert the last needle roller in the set.  The grease also helps prevent the bearings from dragging and falling inward as you carefully align and insert the shaft.  If you load the bearings with a light film of viscous grease, you'll find it much easier to assemble.

 

To help you and other members and visitors, I pulled a first-generation Jeep factory shop manual from my library shelf and copied the transfer case section for the Model 18 transfer cases, including your CJ V-6 era model (both twin- and single-stick shifter types).  Between this and my Jeep CJ Rebuilder's Manual: 1946-71 (Bentley Publishers), you should have all the backup needed:

 

Jeep Model 18 Transfer Case OEM Rebuild Steps.pdf

 

Trust this helps all 1941-71 Jeep and Willys 4x4 owners...

 

Moses

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That makes sense Moses, I did remove the E brake and yoke first but did not remove the input shaft yoke. When I did the intermediate gear slid right out. Glad that is cleared up. I was worried about that for the reassembly. Thank you for the manual download that will come in handy.

 

 

Soaked some parts in Simple Green degreaser overnight

 

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Cleaned them up and sprayed with WD 40 to prevent rust

 

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Kind of weird ! the Simple Green turned some of the parts black, don't know what that's about

 

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Parts are coming this week, sandblasting and painting the case this weekend.

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This looks like a fun project, John!  You'll have a very dependable, classic CJ when you finish, the V-6 is a winner.  I have a good deal of information on the Buick V-6, both odd and even firing types, your nail head 225 plus the later 231 (3.8L) and 252.  Buick took this design to the limit, and it was a G.M. mainstay powerplant for decades.

 

The Simple Green approach is new to me, although it sounds much healthier than a petroleum distillate/solvent parts washer—I know firsthand and can still identify the scent of the original Safety-Kleen solvent from a block away! 

 

My aqueous-based parts washing cabinet can run industrial strength citrus derivative soaps.  I'm currently using Goodson Tools' PJS-50 detergent and running the water/soap solution at about 145-150 degrees F for optimal results.  A washing cabinet changed my work life dramatically, I've had the machine since the mid-'nineties, it's paid for itself ten times over.  Your project reminds me of the CJ-5 I built for the Jeep CJ Rebuilder's Manual: 1946-71.  I'd still be scraping down that frame, powertrain and axles if it hadn't been for this washing cabinet. 

 

For those interested, my washer is a Walker (very well built though they are no longer in business) with a 2-hp/single phase 230V pump, two 4500W heating elements, a 1000 pound capacity turntable and 45 psi nozzles.  The heated solution is approximately 53 gallons.  Bought mine new, made sense at the time.  If you stumble across a similar design, a used machine in good shape, consider buying it, especially if you do any volume of automotive work on older rolling stock like 4x4s!

PJS-50.jpg

Goodson also makes PD-50 and a PD-10 (small quantity) multipurpose degreaser (not for heated jet washing!).  You'll like the cool automotive machine shop tools at the Goodson website, click on the image for a glimpse!

 

As for the Simple Green turning the gears and such black, that's likely the chemical reaction between the citrus concentrates, water and the impregnated, ancient gear oil chemistry...Shouldn't cause a big issue, all of the shafts, gears and such are case hardened and resistant to corrosion and etching. 

 

The beauty of the nozzle/jet washing cabinet, preheated to 145-plus F before placing parts inside, is that critical components like iron castings will "flash dry" after washing by simply cracking open the cabinet door and waiting a few minutes before removing the pieces.  No oxidation/rust issues...I need to demonstrate the Walker in a video, it's really a time saver...I'm very grateful!

 

Moses

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Moses,

 

I am back from vacation and back at it. Unfortunately I had a mishap on the front bearing cap.

When removing the front main-bearing seal. Behind the front main bearing seal is a support ledge for the bearing to set against. I got that ledge instead of the seal and break it off

 

Below is cap before

 

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Below is after showing broken support ledge

 

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Is this a " structual " part ? Do I need to get a new cap? There is still enough of the broken ledge attached where I can slip the broken ledge back in and it will stay behind new seal.

 

JF

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That's frustrating, JohnF!  Post a few reasonably lit close-ups of the damaged section and the chipped section.  Take a photo from each side (front and back views). 

 

I'll share my opinion about the cap's reuse...You can make an informed decision.

 

Moses

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This is what it supposed to look like ( broken pc resting back in )

 

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With the pc removed

 

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showing end of broken pc

 

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JohnF...This bore only supports the seal...The shaft runs through the casting bore without any contact.  The break is so clean that I mistook it for a washer/backer at first!  There is a shelf there, so the piece would likely stay in position with an OEM type double-jacket seal.  The modern replacement seal will typically be a thinner-walled single jacket.  That provides little downward or seating pressure at the jacket seating position.

 

This is not a lost piece, though.  I braze and silver braze, and my first reaction is to reach for the oxy-acetylene torch.  With care, clean parts and the broken "washer-looking" piece seated at its original position, you could place a nice braze right at the junction between the piece and the bearing cap's seal bore.  Brazing temperature should not distort or crack the casting if you concentrate the heat at the junction and do not overheat the whole piece.  Use just enough localized heat to properly flow the bronze or silver rod.  Flux coated would likely work unless you prefer flux powder.  Pre-cleaning before brazing must be very thorough.

 

Note: I'd wrap the piece in a Kevlar or fiberglass welding blanket after brazing to allow slow cool down.  This would be a permanent repair.  The nose bore only supports and centers the seal.

 

There's a curiosity point to this damage, though.  I'm not convinced that you broke this loose.  It looks like the casting ear has been welded or brazed already: See the middle and lower photos, looks like the "arm" has been repaired.  Or is this "factory"?  The case has a lot of black paint covering something, maybe a repair from long before your work?  Does this broken seal seat casting pre-date your work?

 

Moses

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It's factory. My father purchased the Jeep when it was only a few years old. No work has been done to that. I found a housing on Ebay for $ 25.00. I might just get it for pc of mind

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For $25, go for it, JohnF...Sounds like factory welds on that casting from the known history.  If you get a moment, wire brush the paint off that zone I describe.  Let us know if that's a factory weld...very interesting!

 

Moses

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Starting the assembly, First I laid everything out so I am not fishing for parts when I need them.

 

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Started by installing speedometer gear

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Then I put in bearing and snap ring in front cap

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I used a seal installation tool to seat the bearing

 

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Bearing and snap ring installed

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Next I slid in the output clutch shaft into the same bearing.

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Next the short shift fork and shaft

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Next the output clutch gear

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When I painted the case I painted the whole thing then took an orbital sander and sanded the mating surface's this way I can see the high spots

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Next the longer shaft with the shift fork goes in

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I used the old bearing and a deep socket to put on the new bearing on the output shaft

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Next the sliding gear goes into the case and on the shift fork

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Output shaft gear next

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Next slide the output shaft thru the gears

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Next I slid the thrust washer onto the shaft making sure the tab goes into the groove in the shaft that goes all the way back thru the gear

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Next the snap ring

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Washer and snap ring installed

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Next I slid the bearing onto the shaft. Gently tapped it in with a deep socket

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Next the bearing cup

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Got it flush with the case, the bearing cap will seat it the rest of the way.

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Temporarily put the bearing case on with the gasket, no sealer, so I can check the end play in the shaft. I will take this off later to seal the gasket and put on for good. Very important to snug the bolts in a cross pattern so you don't twist the case and break it.

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Fantastic photos, JohnF...Trust you're pleased with your work so far...Interesting to recall how stout these components were and compare them to today's "lightweight" chain drive units.  Aside from the side drive design shortfalls and frictional losses, these Model 18 Spicer transfer cases could handle a 250 horsepower V-8 with ease.  Your 225 V-6 should be a breeze for your fresh rebuild...

 

Moses

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Next I fussed with the shims for a bit until I got it right,

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Needed to do this to clean out the paint in the threads. Should have done it to all the bolt holes before starting.

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After some curse words I got the end play right 0.005 with the rear cap torqued to 35 lbs

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Speedometer gear slid onto shaft, I realized I could have left this off as long as I put it on before installing the oil seal

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Shims sprayed with copper spray-a-gasket and allowed to get tacky

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Bearing cap installed and torqued to 35 lbs. The only bolt I used sealer on at this point was the short one, i need to put the E brake backing plate on later after I blast it and get it painted

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Thanks Mose's More to follow. Let me know if you see something that should be done different :)

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Removed the front cap and installed the seals

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putting in interlocking pin

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Where it should be when recessed in shaft 

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I used gasket shellac from Permatex to seal the gaskets

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Bearing cap installed again

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Next I put the roller bearings into the intermediate shaft

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I put a wood 1 3/16"dowel 2 5/8" long into the shaft to hold everything in place, started with first washer

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I coated the inside of the shaft with assembly grease to hold the bearings in place. I put the 24 bearings in next, then another washer, next 24 bearings then final washer

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Used the assembly grease to hold thrust washers in the case, tabs go into the grooves in the case to prevent them from spinning, bronze side to shaft. I used dowels on each side to hold in place

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Placed the shaft into the case then slid dowels in a bit to hold it in place.

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Put some oil on the shaft and slid it in. If all goes right it should push the other dowels out

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Shaft in

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JohnF...Looks like you did use sealant on the rear bearing shim stack gaskets, right?  I use either a thinner shellac-like sealant or Gasgacinch on shim stacks.  Gasgacinch spreads evenly while wet, so does a thinner "shellac" like Permatex 300D, spray High Tack, etc. 

 

The aim is to allow the sealant to squeeze/spread flatly and not interfere with an accurate setting of the bearing load.  Sealant should be thinly and evenly applied, on the bolt threads, too, then tightened and torqued before the sealant dries.  This prevents leaks and weep.

 

Just a comment...Your detailed photos are immensely helpful to others, JohnF...Thanks!

 

Moses

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JohnF...Looks like you did use sealant on the rear bearing shim stack gaskets, right?  I use either a thinner shellac-like sealant or Gasgacinch on shim stacks.  Gasgacinch spreads evenly while wet, so does a thinner "shellac" like Permatex 300D, spray High Tack, etc. 

 

The aim is to allow the sealant to squeeze/spread flatly and not interfere with an accurate setting of the bearing load.  Sealant should be thinly and evenly applied, on the bolt threads, too, then tightened and torqued before the sealant dries.  This prevents leaks and weep.

 

Just a comment...Your detailed photos are immensely helpful to others, JohnF...Thanks!

 

Moses

I saw on several sites to use the copper form a gasket spray on the shims. I sprayed on a few coats then let it get tacky. Besides whats a Jeep if it doesn't leak a bit

:-)

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