sloppy pinion

i swapped a 3.55 geared D30 into my manual cherokee (stock came with 3.55s) and rebuilt everything with the notion that i would be able to build my stock axles while getting a little better gas mileage. the single thing i neglected, was the pinion bearing. i knew it wasnt super tight, but didnt think itd be an issue. i was wrong, and now its an issue.

i have about 20-45 degrees or rotational play in the pinion yoke. gears looked fine when i swapped the axle in and replace the axle seals.

long story short... can i simply replace my pinion bearings, the crush sleeve, pinion nut, and pinion seal, and be happy... or am i looking at a regear sooner rather than later?




ive google searched and havent found anything... and ive heard mixed answers from people who i consider to be knowledgeable.

Rotational? How would that be a bad pinon bearing? wouldn't that be backlash? or am I not understanding and 20-45 is a pretty big window. Dana 30s use spacers not crush sleeves, I would think you would be fine, you have to pull out the carrier to drive the pinion beaing off.

I'm not understanding your first statement...changed a 3.55 D30 for another 3.55 D30 hoping to get better mileage???? Also, you state you "rebuilt everything". did you disturb the ring gear? I agree with whitexj98...doesn't sound like a bearing issue, more like a gear set-up issue (backlash).

excuse me... my manual cherokee came with 3.07s.

you have to pull the carrier to replace the axle seals. but im 100 percent sure everything went back together exactly the same way. from what i was told and read, this was an acceptably procedure. before hand, i have never opened up a diff.

once on the road, it did not have the rotational place i described. but after a day of wheeling, it now does.

Pinion bearings would cause the pinion shaft to move in or out, or side to side.

Excessive backlash (Rotational Play) is caused by not having set up your gears correctly. You can't just swap the guts from one carrier to the other. Even though mass production gets things close, the depth of the pinion, the bearing preload ,and engagement of the side gear need to be set for each case you put together.

You will need to make a set of "Setup Bearings" out of your old bearings so you can easily replace the pinion shims until you find the right size. You will also need to get various sizes of shims for the carrier bearings. They sell a "Setup kit" with shims and bearings for this purpose. The bearings in the kit are the bearings you put on after you have found what size shims to use.

Hope that helps.

Best thing to do is pull the cover and check back lash using a dial indicator, see what it is compared to the specs and go from there.

Ring and pinion gears are to be serviced (replaced) as a matched set. There are numbers stamped on the pinion gear and ring gear that should match.

If you can't find the pinion gear that matches the ring gear you may want to consider reinstalling your original differential.

You didn't state what year your XJ is. If it is a 2000 there is a possibility it uses the crush sleeve for the pinion. See the following Dana/Spicer manual.

http://www2.dana.com/pdf/X510-6.pdf

We all may be a little confused. Did you replace the entire axle, or just the guts from a donar axle. When you say you rebuilt everything, did you put in new carrier bearings? I ask because if you change the bearings its more than a remove/reinstall...it will need to be set-up to spec again with new carrier bearings even if the ring and pinon were removed and replaced in the same axle housing.

the entire axle was replaced... carrier removed, axle seals replaced, everything reinstalled exactly as it was and tightened to specs. my knuckles, shafts, and unit bearings were swapped over. control arm bushings replaced, all 4 ball joints, LCA skids welded on.

the bearings were not tampered with, and the pinion was never removed.

'97 XJ. the axle was out of a '90. since it was equipt with a 242 Tcase, it did not have the vacume disconect.

alright, i think i have remedied this for the most part, and found the remaining issues. when i installed the 3.55 geared axle into my manual cherokee, i replace:

ball joints
upper CA bushings
the polly bushings in my RE arms
all steering components
the passenger unit bearing i swapped from my old axle was less than 5k miles old.

this weekend i popped my cover and did some investigating. i found that my ring and pinion was...

dun,
dun...
DUN!

100% fine.


thats right. but i noticed that slop was coming from the drivers side spider. but the passenger side was not moving at all. turns out the driver side u joint was trash, along with the unit bearing. i was unaware that slop in those components could be felt all the way into the drive shaft. replaced those, and the pinion yoke is a LOT tighter, not to mention the whole jeep rides better. passenger side U joint and unit bear are solid, no play there.

now, there is still a tiny by of slop at the pinion, and it appears to be in the carrier. when i grab the ring gear, i cant move the pinion without the ring gear moving. there is zero slop there. it appears to be coming from the spiders. i assume there are bearings in the spiders, is it possible for these to wear out and need replacing? would something like a lunchbox remedy this?