jolson05

Is this too much movement in the rear differential pinion?

See video...
https://youtu.be/69epUhyT5bk

2013 Rubicon Unlimited Rear Differential Pinion Slop.

After removing differential flange I sprang a leak and diff oil leaked at a pretty good stream till it stopped.

Diagnosis? Resolution?

Bad pinion seal? Bad pinion bearing? Replace pinion seal and/or replace pinion bearing? I'm hoping it's just the seal.

Any help is appreciated. Thanks in advance.

Rebar-7

So your initial reason for removing Pinion Nut an Flange was because the seal was leaking ? Or what ? IMO it does seem a little excessive , there will be some movement just because there is no preload on it . Was there movement on the pinion before you took the Flange off ? It should still be under warrenty take it in....

jolson05

^ Thank you for the response. I took the flange off to install the new TW 1310 DSs.

easttnruby

once you put flange back on torque down the nut, should be a lot more "secure". I once had the flange nut back off and had the same slop and leaking. swapped out the seal, reseated the bearing when I TQ'd it all back up. Problem solved and all works well. Obviously, it wouldnt hurt to pop the diff cover and give all your gear teeth a look/ inspect fluid for metal.

Matth

I changed my rear drive shaft last week. For some reason my 08 rear didn't come with new seal. But the 15 in the same shop with same shaft said to change the seal.
Wonder why?
But like you said after reinstalling the leak stopped.

anvil15

The yoke seals the lube in the housing via the seal around the pinion. Once you take off the yoke, the pinion bearing is loose and you will get that kind of side movement. I believe the diff uses a crush sleeve to set bearing preload, so the new yoke and the nut must be tightened exactly the same to get the same preload. In a practical sense, it is best to remove the ring gear and carrier to check preload as you tighten the nut. Also be sure the bearing does not **** and make it seem it is tight when the nutt is one thread or so loose still. Hopefully you can get the nut tightened properly with the wheels up and turning the pinion by hand several palces through its rotation, back and forth in the backlash range. That range is a combination of ring/pinion backlash and spider gear backlash. As you continue turning past the ring/pinion range, you will feel the turning get a big harder while turning the pinion gears against the axle shafts and side gears.

The site editor does not like the correct word for the bearing not being fully seated and jamming up, so it put in asterisks.

Invest2m4

The above is correct. Pinion bearing pre-load needs to be measured before removing the nut and then torqued back to the correct setting. You are playing with fire by picking some random value such as 160 ft lbs. Some don't have issues, others fry a pinion bearing in 1000 miles. In a worst case, it requires a new R&P.