Alberto_YJ Posted May 15, 2014 Share Posted May 15, 2014 Good afternoon, I'm looking for information about all that we should know before servicing an axle. I'm not an experienced mechanic, so I like to investigate before mess it up. Which one will be the best fluid to fill up the differential? I've read about API GL-5 and 75W-90 specs for this. I've also read about a limited slip differentials and an additive to be required for that one. So, how can we identify the axle that we have, starting with this, I've read that the D35 has a plastic plug. But mine has a threaded one. What things can we look for, to identify the D35 and D30 axles? How can we identify or distinguish the limited slip one? Thanks in advance. Alberto. Quote Link to comment Share on other sites More sharing options...
nbruno Posted May 15, 2014 Share Posted May 15, 2014 Alberto, most likely you have a D35 in your yj. You could confidently use mobile1 75w90 with lsd additive. It should take about 3.5 pints, the dana 30 would take 2.5 pints Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted May 16, 2014 Administrators Share Posted May 16, 2014 I have always liked Mobil synthetic products. However, for our 1999 Jeep XJ Cherokee Dana 30 and Chrysler 8.25" axles with ARB Lockers, I use Mopar 75W-120 synthetic gear lube. I use this same lube in the 9.25" and 11.5" AAM axles in the 2005 Ram 3500 4WD truck. 75W-90 synthetic would also work well in either of these applications, though I prefer the 120W equivalent protection during our extreme high desert summers. I agree with nbruno about Mobil 1 gear lube, too. Whatever is readily available in your area would work. One caution with any synthetic conversion on a high mileage axle: The "false seals", actually varnish, on the pinion and axle shaft seals can wash out from the high lubricity and viscosity of better synthetic lubes. Seals begin to leak... I use synthetic lube on newer units and axles I rebuild. Use your judgment if the Wrangler looks like it still has original (25 year old) OE seals. If the lube looks and smells like conventional 75W-90 or straight 90W gear lube, I would stay with conventional oil until you either reseal or rebuild the axles. You could use a quality 75W-110, 85W-120 or other viscosity variations—but use the conventional, non-synthetic gear lube version for now. My view... Moses Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted May 16, 2014 Administrators Share Posted May 16, 2014 Alberto...If you have a limited slip, friction modifier is usually a requirement. This would be the rear axle, and the differential will have a friction clutch assembly in the middle that you can see with the diff cover removed. There is often a tag on the limited slip axle housing, specifying the need for friction modifier or special lube. Mopar offers the friction modifier, there may be other local sources at Colombia...This is a Spicer automatic locker differential if your Wrangler has it, so you're looking for modifier that serves that type factory locker. The option was not common, you likely have the "open differential", which looks like the front axle's differential...Let us know. As for the rear axle fill plug, your rear axle is definitely a Dana 35. Earlier versions do use a metal fill plug. The front axle is a Dana 30 as you note... Moses Quote Link to comment Share on other sites More sharing options...
Alberto_YJ Posted May 17, 2014 Author Share Posted May 17, 2014 Moses / nbruno, thank you very much for the information, so I will start with conventional oil for now, until a rebuild is made. I will post some pictures if I can do this tomorrow. Regards. Quote Link to comment Share on other sites More sharing options...
Alberto_YJ Posted May 19, 2014 Author Share Posted May 19, 2014 Good morning, yesterday I did my first diff fluid replacement on a rear axle. See pictures and video that I took and let me know your opinion. I filled it up with Mobil general purpose gear oil 80W-90 for now. Will take time in the future to replace bearings and seals and swap to synthetic oil. Regards. Vídeo.MOV Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted May 20, 2014 Administrators Share Posted May 20, 2014 Great work, Alberto, you did a correct fluid replacement. The sealant bead is appropriate. From the video, you tightened the cover securely. I could not see any shiny pieces of metal in the drain oil. That's always a good sign. No metal means no broken or chipped parts. The teeth of the ring gear look good from what is visible in your photos. The inside of the differential case is not visible. (Too dark, flash fill from the camera would have helped here.) I could not tell whether the differential is open or a Trac-Loc limited slip. I tried editing (brightening) your two diff photos, but the resolution is too low. If you Email these two photos to me at higher resolution file sizes (more pixels), I can edit/brighten the pictures and evaluate whether the diff is a limited slip. If the diff is a limited slip, you can read the Mobil lube label to see whether this lube works for both a conventional lube and a limited slip lube. The label may also note whether or not additional friction modifier is necessary. If you do need to add friction modifier, that would not be an issue. You can add friction modifier (only if necessary) without disturbing any of your work. There would be no need to remove the cover. There are other ways to determine whether an axle is a limited slip. The quickest way is to jack both rear wheels safely off the ground. (Use jack stands.) With both tires above the ground and the transmission in neutral, rotate one wheel in the forward direction. If the opposite wheel rotates in the same direction as the wheel you are turning, the differential is a limited slip. If the opposite wheel rotates backwards or does not rotate at all, the differential is "open" or conventional, without a limited slip. Moses Quote Link to comment Share on other sites More sharing options...
Alberto_YJ Posted May 20, 2014 Author Share Posted May 20, 2014 Moses, I will try to determine if it is a limited slip or not when I take the YJ to the car washer... I do not have even the factory jack, no jack stands either... I'm selling my 2009 Toyota LC90, it seems that today I'm going to get the payment, so I can start ordering used factory parts, as the jack, wrench, passenger seat belt, etc. I will buy some tools as well, the only tools that I have for now are a small socket and wrench set and a screw drivers set. The steering wheel puller, a greaser and a torq-meter are coming my way. About the video, It only shows the diff cover removal, I've not torqued the bolts yet, Just tighten a little bit and will torque them when the tools arrive. Forgot to tell you something that I think is critical... I've noted that I'm missing the pin that holds the spider gears shaft. The shaft didn't come out and I'm thinking that it could be broken... Not sure. Thank you for your comments. Alberto. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted May 20, 2014 Administrators Share Posted May 20, 2014 Good to have tools for your planned projects, Alberto! Your photos could answer the limited slip question if we brighten up the diff pictures to show whether there are friction discs between the diff case and the axle shaft side gears. The "missing" lock pin retainer on the pinions or "spider gears" shaft is very important, as this lock pin holds the pinions/spider gears shaft in place. Warning: If the pinions/spider gear shaft works its way out on a C-clip design axle, the axle shafts can slide inward, C-clips drop loose, and the axle shaft(s) can slide out the side of the vehicle. This results in severe damage or an accident due to loss of vehicle control. On both the C-clip and non-C-clip axles, if the pinions/spider gear shaft slides out, it can destroy parts or even cause axle parts to seize. The rear axle could lock up and cause a severe loss of vehicle control and an accident. According to the 1989 factory service manual (U.S. edition), your rear Dana 35 axle should not have a C-clip design axle. You should have press-on axle shaft bearings and bearing retainer plates at the outer tube ends of the axle housing. The retainers keep the bearings and axle shafts from sliding out of the axle housing, and the axle shafts with bearings are a snug fit into the axle tube ends. These "seal retainer" plates attach to the brake backing plate studs. Some differential carriers (typically those with C-clip axles) use a retainer bolt to hold the pinion shaft in place. These bolts are notorious for snapping during removal. This ends up a major problem, as the high tensile strength sheared bolt shank must be removed before the axle can be serviced. (I'll save this repair for when such a question comes up in the forums.) Most often, during axle shaft bearing or seal replacement service, the bolt snaps as you try to remove it. In your situation, if this is not a C-clip axle, you should have a pinion/spider gear shaft "lock pin" and not a lock bolt. You may be able to install a new pin with the differential still in the axle housing. Access may be an issue, but this part is very important. If you cannot install the lock pin retainer with the differential case and ring gear in position, you will need to remove both axle shafts and the differential case with the ring gear to access the lock pin hole. First see if you can access the retainer pin hole without removing the differential case. Here is the illustration of an "open" differential, not a limited slip. Zoom-in for details. (Your mouse scroll wheel may be necessary for this step.)...Note the role of the shaft lock pin, Mopar P/N S0455313. This may be a generic part number: 1989 Wrangler Rear Axle.bmp If you have Trac-Lok, that differential also uses a lock pin to hold the differential shaft in place. Here are the Mopar part numbers for the Trac-Lok differential spider gear (pinions) shaft lock pin: PIN, Retaining...83505019 (1987-89); 05252502 for 1990 You do need to take care of this lock pin issue right away, Alberto... Moses Quote Link to comment Share on other sites More sharing options...
Alberto_YJ Posted May 20, 2014 Author Share Posted May 20, 2014 You are right Moses, this is not a C-clip type axle, I've seen a video on youtube where the difference is shown. I saw the hole and there was no head for a bolt, that is why I've said that the retainer bolt/pin is broken (maybe). If the pin is not there I think that the shaft would fall from its place when turning... I will send you the pictures in full resolution to see if you can edit them to identify the limited slip if any. What I'm sure is that there was no metal pieces inside when I drained the old fluid. For the Lock pin, how can I remove it in the proper way? Thank you again. Regards. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted May 20, 2014 Administrators Share Posted May 20, 2014 Alberto...These two photos are great and could be lightened. You can send me larger files, I'll brighten them...Can then identify the diff type and features. The pin is often a spring roll pin. Before you assume the pin is missing, take a look inside the pin bore with a mirror and light. There may be a spring roll pin inside the bore, it would not surprise me. If the pin is actually missing, I would expect the shaft to have slipped out of there by now. Moses Quote Link to comment Share on other sites More sharing options...
Alberto_YJ Posted May 30, 2014 Author Share Posted May 30, 2014 Good morning Moses, I had not driven my YJ since I made the fluid replacement. Yesterday I went to the city, a short 20 Mile trip at speeds from 35 to 60 Mile/h. When I got back home I've noticed that the rear axle was making much more noise than the last time, Actually I found that is not a "knock" but like the diff is locked and forced on paved surface. I'm suspecting that the diff could be the Limited slip type one. When the vehicle is cold I can feel the same problem but it has been worst after the temp has increased on the axle I think. So, by now I will let the vehicle parked until I can clear this and add the modifier if needed. Does this description tell something to you Sir? Regards. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted May 30, 2014 Administrators Share Posted May 30, 2014 Since you only changed the fluid and got this reaction, it does sound like a limited slip without friction modifier in the fluid. If you can get the rear wheels off the ground safely like I described, you can rotate a rear wheel forward and watch the other wheel turn. Both turning in the same direction is a limited slip. You can also have someone hold one wheel and feel the force across the axle as you rotate the other wheel. If you determine that the axle is a limited slip, get some friction modifier. Mopar and others sell this in smaller quantities for one-axle supplement. You can add this to the differential fluid. If the axle lube is full, siphon a small amount of lube through the fill hole. Then add the friction modifier. This way, you will not disturb the diff cover that you installed. The Mopar P/N for friction modifier that works with a Trac-Lok diff is: 04318060AB. It sells in 4 oz. quantity bottles for $8-$12 (U.S.). Wynn's and others make friction modifier, too, be sure it's for a Spicer/Dana Trac-Lok axle. One bottle should do it. I've used two bottles on very stubborn Trac-Lok units like our '02 Jeep Liberty 4x4 rear axle at 30K miles. Moses Quote Link to comment Share on other sites More sharing options...
Alberto_YJ Posted July 2, 2014 Author Share Posted July 2, 2014 Some days away, but still trying to get my YJ how I want to. Finally got the Mopar friction modifier. Yesterday I've put some fluid out of the differential and poured the friction modifier in. Does the modifier takes some time to make effect? or should I notice the change right after pouring it into the diff? I've been driving the Wrangler during 1 hour but when I got back home in a tight turns the weird sound is still there. Any suggestion? Regards. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted July 29, 2014 Administrators Share Posted July 29, 2014 Hi, Alberto...I've had Jeep limited slips that required two of these 4 oz. bottles of the modifier. This was true for our 2002 Jeep Liberty, bought new. At 30,000 miles, it started the notchy, grabby rear axle thing you've described. I added modifier, the troubles ended. The problem was very common to that generation of the Liberty. Two bottles seemed to work well. If this has not cleared up, and if you're sure this is a friction plate automatic factory locker, try one more bottle of the friction modifier. Trust you're enjoying the summer weather at Colombia. Must be fun this time of year! Moses Quote Link to comment Share on other sites More sharing options...
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