Dana 35 Trac-Lok Spider Gears

[Alberto_YJ]

I've mentioned something about a knock noise coming form the rear end on my YJ Sahara Edition in other post, but would be better to have this issue discussed separately from the other topic related to miscellaneous engine parts missing.

 

Finally got the differential carrier out of the axle to inspect every component. Found that one of the pressure washers (not sure if is that how it is called) was cracked, so it wasn't doing any pressure against the clutch pack on the driver side at all. So the rear end was feeling like it was locked all the time, specially in tight turns to the left.

 

I've ordered a complete clutch and gear replacement set and noticed that the gears are different from the ones that I have already installed. It looks like they were for C-Clip shafts but I see no problem if the shaft is non C-Clip type.

Anyway, I would like to get some coments for all you that have more experience in this matter.

Vendor says that this is an improved kit that will work with C-Clip and bolt on axles.

 

All carrier and pinion bearings replacement ordered as well, replaced side bearings and heading to replace pinion bearings this next weekend.

 

There was a lot of shiny metal particles in the differential fluid. The shaft bearings grease seems to have some as well, the grease looks gray instead of Red, its original color.

 

Regards.

[Moses Ludel]

How do these new parts compare with your OE differential gears?  IS there a shoulder at the right location for the clutch parts?  There is now a recess for inner C-clips, which you don't need but does make the gear set "universal" for fit.  Line up the pieces and check the depth to make sure they'll fit and match, Alberto. 

 

This should be a relatively easy fit up, as you're not changing the ring-and-pinion gears or the differential case.  Make sure you use (or reinstall) the same thickness pinion bearing depth shims.  Set the new pinion bearing adjustment crush sleeve and bearing preload with care, do not over-tighten the bearing load.  If you crush the sleeve too far, you will need to install another new crush sleeve.  You cannot simply "back off" the pinion nut, as the over-crushed sleeve will not support the backside of the bearing.  Bring tension up gradually.  Stop at the proper bearing preload. 

 

Carrier bearing shims should also be reused—or matched at each side to the original thicknesses if you install new shims.  Since you're reusing the OE differential case, this should restore the carrier bearing preload.  The only additional concern is ring-and-pinion backlash, which should be the same as original if you reuse the carrier bearing shims at their correct, original positions.  Check the gear backlash, it should be within specification.  Running a tooth contact pattern helps, too.

 

All of this should be right if the axle was set up properly in the first place (either by the factory or done correctly aftermarket).  Assuming all's original, you should find that the new bearings are so close to the original bearing sizes and fit that each adjustment will be within specification.  Verify bearing preload adjustments, of course.  This should be straightforward.

 

Let us know how this works out...

 

Moses

[Alberto_YJ]

Moses, first of all, thanks for your cooperation and information sharing as usual.

 

I've got bad news, already installed new side bearings but there was no shims. I'm not sure if the bearings I removed were the factory ones, they were Timken and noted that the one on the left (the side the clutch pack had the pressure washer cracked) was heavily damaged and the race was slipping on the carrier.

In the other hand, there are trust washers on both sides and a kind of black silicone around the axle tubes where the trust washer sits, one has falled of and breaked.

 

Actually I'm not sure if the knock noise was coming from the bad clutch pack or from the slipping bearing race over the carrier...

 

Let me know your opinion about this. Thanks again.

 

 

 

 

[Alberto_YJ]

Another question emerged, I'm going to use Shell Synthetic gear oil 75W90. Do I still need to use Mopar's friction modifier additive?

 Thanks.

[Moses Ludel]

Alberto, it sounds like time for a new differential case.  You have the internals for Trac-Lok, should likely stick with that design.  You'll need a new (or "good used" if there is such a thing) case to correct the spinning bearing race issue.

 

There should have been shims between each carrier bearing cone and the shoulders of the diff case.  There are also the 0.142" thick spacer shims used commonly on conventional differential cases, one placed on each side of the diff case, outboard of the carrier bearing races between the axle housing and the backside of the bearing cups.  Do you have these spacers?  Sometimes, an axle builder will attempt to shim the carrier bearing load with shims placed alongside these thick shims to set the gear backlash and the bearing preload.  Technically, the axle build requires both these thick shims and the stack shims behind the carrier bearing cones.

 

Do you have a factory workshop manual or equivalent for setting up the axle?  The immediate concern here is carrier bearing preload and the final ring-and-pinion gear backlash.

 

I would use friction modifier with the synthetic oil.  Mopar uses factory synthetic gear lube plus friction modifier with the Trac-Lok.

 

Moses

 

P.S:  I need to do a Vimeo On Demand streaming video rental of the Jeep Dana 35 rear axle build!

[Alberto_YJ]

Well, those are bad news for me, first because I've already installed the carrier bearings, I do have the thick shims between the axle housing and the bearing cups. Actually the carrier got in a bit snug, I had to tap it a little with a rubber hammer to get it on place. Found that the brackets holding the bearing cups where in the oposite side and upside down since the last service, now they are matching the marks on the axle housing.

 

As for now I need to get the vehicle running again ASAP. Won't be able to get the shims between bearings and case and even more difficult to replace the case.

So the carrier, main pinion and shafts are all in place, cover in place and fluid poured inside with Mopar additive. I'm happy there is no leaks from the cover.

 

As I've removed the gas tank to fix some rust issues between poly tank and skid plate, this will be the next step, to mount the tank on the YJ. If you don't have a vehicle elevator (as me) removing the tank will give you a lot of room to work in the differential, specially if you have 20 gal tank.

 

Next time I replace the carrier bearings I will get the shims and replace main pinion bearings as this time I've got the wrong ones.

 

Every time I start fixing any issue, I will find a new one. This time, found that some studs are barely stripped and made the nuts to be completely useless.. tried some from the other wheels and got at least 4 tight on each one of rear tires until I can buy new studs and nuts.

 

 

Thanks again for your valuable information. Regards.

[Moses Ludel]

Alberto...It is normal for a snug fit of the bearing cups when the carrier bearing preload is correct.  The carrier bearing preload test involves rotating the adjusted pinion shaft with an inch-pound torque wrench to confirm the carrier bearing preload.  Historically, the best way to install Dana/Spicer carrier bearing cups (once bearing preload shim thickness is established properly), is to cock the bearing cups slightly and use a rawhide or plastic head hammer (ideally sand filled), tapping side to side evenly on the bearing cup outer edges, until the bearing cups have each squared up and seated.  Then install the bearing caps and confirm the carrier bearing preload.

 

Preload on the carrier bearings is only set after the pinion shaft depth and pinion bearing preload are correct.  (If the pinion is in already place and adjusted properly, you can simply confirm the preload on the pinion shaft.)  In assembly sequence, I always begin with: 1) set correct pinion shaft depth, 2) set the pinion shaft bearing preload, 3) set ring and pinion backlash with a temporary shim stack at the outer (thick) shims, then 4) set the carrier bearing preload while maintaining the proper ring-and-pinion gear backlash.  At this final 4th step, the carrier shims and spacers get placed in their correct locations.

 

Moses