Chrysler 8.25 carrier bearing preload?

[jeepindavis]

I'm replacing my open carrier in my Chrysler 8.25 with a Mopar limited slip. I've got the ring old gear and new bearings on the carrier and I'm looking for preload specs for the carrier bearings and some way of successfully threading the holders in - I was thinking of modifying an appropriately sized hole saw with a grinding or cut off wheel so the teeth will properly engage the threaded seat for the bearing cones. Any thoughts? Thanks!

[xjtrailrider]

Off the top of my head, 100ftlbs but i would have to look at my notes.

[jeepindavis]

The torque spec to which I am referring is the bearing preload, not the bearing caps - which I know is 100 ft/lbs. Are you thinking the preload should be 100ft/lbs or did you misunderstand the specs I'm looking for? That seems high for bearing preload.

[bgwyllys61]

the bearing adjustors have a "hole" for lack of a better term right now, that is the same dimension as the pinion nut, so, you can go buy a new pinion nut, and weld it on to an extension, and it works perfect, unfortunately, I didnt find this out til after I had spent the money on the adjustor tool, and then figured out what they were selling was exactly that, a pinion nut welded onto a short extension

[RCP Phx]

Originally Posted by bgwyllys61

the bearing adjustors have a "hole" for lack of a better term right now, that is the same dimension as the pinion nut, so, you can go buy a new pinion nut, and weld it on to an extension, and it works perfect, unfortunately, I didnt find this out til after I had spent the money on the adjustor tool, and then figured out what they were selling was exactly that, a pinion nut welded onto a short extension

Wrong!The adjuster is 36mm.

[kastein]

Sounds like an old nut off a d30 shaft would work nicely then.

[89xjgrey]

Pinion bearing preload on the 8.25 is around 12-15 Inch pounds. Are you referring to backlash on the ring gear?

[RCP Phx]

Originally Posted by jeepindavis

I'm looking for preload specs for the carrier bearings

Originally Posted by 89xjgrey

Pinion bearing preload on the 8.25 is around 12-15 Inch pounds. Are you referring to backlash on the ring gear?

Screw Adjuster Design: Oil the adjuster threads on both the housing and on the adjusters themselves. While holding the races on the bearings, place the carrier in the housing. Install the carrier caps according to the marks made during disassembly so that the threads are seated evenly on the adjusters. Third member differential designs require a 10 to 12 inch spanner wrench to tighten the adjusters. Chrysler differential designs require an extension bar and special spanner to access the adjusters through the axle tubes. Tighten both the left and right adjusters evenly by hand until they are fairly tight. If the backlash is too wide, tighten the left adjuster until the backlash is correct. If the backlash is too tight, tighten the right adjuster until the backlash is correct. If necessary, open one adjuster and tighten the other. Both adjusters must be fully hand tightened when acceptable backlash is obtained. The final adjustment should tighten the left adjuster since the ring gear is forced away from the pinion gear while under load.

[89xjgrey]

I didn't think there were any 'preload' specs on the 8.25 carrier bearings. They press right onto the carrier, without shims. All adjustment is made using the side adjusters.

[xjtrailrider]

Originally Posted by jeepindavis

The torque spec to which I am referring is the bearing preload, not the bearing caps - which I know is 100 ft/lbs. Are you thinking the preload should be 100ft/lbs or did you misunderstand the specs I'm looking for? That seems high for bearing preload.

I was referring to the carrier bearing pre-load adjusters, cap torque is 60ftlbs

Straight from the Yukon installation manual page 11 , I was a little low on my spec.


Screw Adjuster Design
The easiest method uses screw adjusters to set the backlash and carrier bearing preload.
Carefully oil the adjuster threads on both the housing and on the adjusters themselves.
Note the order in which you tighten the adjusters so the backlash remains consistent, even
when subjected to heavy loads.
The pinion gear always forces the ring gear away from itself whenever it transfers power.
Start with a looser backlash setting than the axle’s manufacturer calls for and always
ensure that the last adjustment made to the left adjuster tightens it.
If the backlash becomes too tight, loosen the left adjuster first, followed by tightening the
right adjuster. To reestablish the backlash setting, tighten the left adjuster. Ensure that the
last adjustment made to the left adjuster tightens it to eliminate any space between it and
its bearing race. Any space or looseness on the left side will let the carrier deflect when
under load, and this will allow backlash to open up when driven under load.
Once the backlash approaches the manufacturer’s recommendations, tighten both left
and right adjusters evenly to increase carrier bearing preload. Set the carrier bearing preload
to approximately 150 to 200 pounds/feet. It is difficult to damage bearings with excessive
carrier bearing preload on a screw-adjusted differential.


I made 2 adjustment wrenches from two D-30 spindle nuts, two 3' long pieces of 3/8" black pipe and two 1/2" socket adapters, I welded the nuts to one end and the socket adapters to the other so I can use a ratchet or a torque wrench to set the pre-load.

[bgwyllys61]

Originally Posted by RCP Phx

Wrong!The adjuster is 36mm.

yep, I was wrong, my bad, I got the two confused