Bigbee

Dealer replaced weeping pinion seal on my recently purchased stock 98. Also got new front tires the same day as the old ones were cupped badly and humming. Well, now I can't hear the tires, but do hear the rear diff whining a bit from 40 mph to around 70. Question is does replacing the pinion seal require setting backlash or anything that would otherwise make it whine, or was it probably doing it before and I just couldn't hear it over the front tires? Are the carrier bearings getting tired at 89,000 mi. maybe? Would like to take it back to the dealer as soon as possible if it's something they f'ed up.

01ssreda4

iTrader: (96)

Typically at 100k the bearings are worn but usually look good, especially in auto cars. They have a little more play then normal but have no major flaws. The way they replaced the seal would determine what could have been done. What I think they would have done: Marked the driveshaft, yoke, and pinion nut, then replaced the seal, and put everything back together based on the marks they made. The correct way would be to : not mark ****, replace the seal and crush sleeve, and retighten the nut back to about 10 inch/pounds on the new crush sleeve. The second way is more time consuming obviously.

hiltsy855

iTrader: (35)

Ya, like 01 said they probably didn't bother to replace the crush sleeve and get the pinion bearing perload right.

01ssreda4

iTrader: (96)

To prove my theory, get the car on ramps and go under and look for marks on the yoke, driveshaft and pinion nut. This could give you a clue as to which procedure they used.

Bigbee

Will get under there today and take a look. Thanks for the info.

Ls2SilverBullet

Good info. I need to do my pinion seal soon.... So new seal and crush sleve put on at 10 inch lbs... dosnt get much easier... sweet

96lt4c4

iTrader: (5)

I would have replaced the pinion bearings, new crush sleeve or spacer, and new seal. That would be the right way to do it if it had 100K miles on it.

lt1pwr1

iTrader: (1)

I replaced mine last year using the marking method and don't have any whine at all. I don't think it is a wrong way to do it at all. Keep in mind my car now has 260K miles on the original rear end.....

More than likely, he didn't tighten the nut to the exact spot he marked it at. He may have tightened a little too much which would explain the whine you are hearing.

01ssreda4

iTrader: (96)

Definitely not saying you can't be successful doing it this way, I just think it lowers your successful %. And as stated, the bearings probably should have been replaced also. I like to do complete rebuilds on 10 bolts anyway

hiltsy855

iTrader: (35)

Just to be clear, you want to tighten the pinion nut until it takes 10 in-lbs to rotate the pinion. You'll need a breaker bar and maybe a big cheater bar to get it tight enough.

Ls2SilverBullet

So you are saying to brace the pinion with a breaker bar so you can properly torque it past 10 inch lbs or what? B/C only 10 inch lbs seems like no torque to hold all that together.

joecar

He's saying that after you tightened the nut tight (a lot more than 10 inlb), it should take 10 inlb to rotate the pinion.

01ssreda4

iTrader: (96)

Yep, you need to read a write up to familiarize yourself with the crush sleeve procedure.

Bigbee

Well, got under the car and checked. Looks like the new seal is leaking and there are punch marks on the pinion shaft and nut. Didn't see anything on the yolk but with the torque arm it's hard to really get a good look up on ramps. I guess it's going back to the shop for re-work and I'll ask them about using a new crush sleeve and setting the torque right. Are the pinion seals really problematic on these? Have had several newer G80s with no leaks.

96lt4c4

iTrader: (5)

Yes 10 bolts are known to have pinion seal leaks. It gets worse when the pinion bearings are bad. You may have a grove worn in your yoke.

Bigbee

Went back to the dealer today and they tell me the pinion bearings are a bit worn which is taking out the seal and causing the whine. Quoted me $675 for repairs but if I do have them dig into it, I'd probably put in all new bearings and what not so not sure how much more that would be. Not making that much noise so I think I'll just drive it as is for awhile and see how things go. Putting it away for the winter soon anyway. Thanks for all your comments.

whytryz28

iTrader: (28)

For that much i would hunt for a used 12 bolt.

01ssreda4

iTrader: (96)

Please take a pic of the punch marks. The new pinion nuts in the Ratech kits have round punch marks to distort them on purpose so they don't back off. I don't see how you can see any of the pinion with everything assembled...none of it is exposed except the tip which would be behind the u joint. BTW, what they told you was bullshit.

Bigbee

Okay 01ss, here is a pic of the pinion nut. You can see the punch marks on there. Do tell...what are they bullsh*tting me about.

01ssreda4

iTrader: (96)

Nice job by them.........NOT!!!

Those are their punch marks, so there is your answer.