hlaalu

iTrader: (3)

I took in my rear to a recommended shop to have them change a leaking pinion seal, axle seal, and axle bearing. The rear end works great, no leaks, but it is whining very loudly. I want to change the oil and add some GM additive and see if that does anything before I bring it in again. It's an auburn posi with 90k miles, what would you guys recommend I fill it up with? Thanks.

Spartan7

iTrader: (7)

How loud? If the stock gears were reused, they might whine a little after being set back up. But if it's really loud, then it wasn't set up right. No fluid change will help that, but if you really want to, go with Mobil 1 or Amsoil.

DaddySS

Just because is it is a recommended shop doesn't mean the guy doing the job did it right. If it whines more after that work - they did it wrong and you should take it back - period.

hlaalu

iTrader: (3)

it's whining very loud, i can hear it over my dumped exhaust. they shouldn't have had to touch the gears replacing a pinion and axle seal, would they?

zaner

iTrader: (16)

I got a set of GM 4.10 gears out of a wrecked s10 truck...I had them installed and the installer said the gears looked great and no major sings of wear. After he installed them, we put in synthetic rear end fluid with the gm additive. The gears whine slightly but not on acceleration or deceleration...they only whine when cruising around 50 mph nothing before that mph.... seems strange. Ive had this installer install countless gears and theyve always been very quiet. I asked him and he said it could be due to them being used at one point. We rechecked everything and it looks dead on.....go figure

alamantia

iTrader: (10)

Does it whine on deceration or all the time?

When the rear is initially set up the pinion nut is tightend enough to establish preload on the inner and outter pinion bearings. Too loose and the pinion will wobble around and destroy your gears. Too tight and the rear will run verry hot due to the friction. Setting pinion preload is detremined by tightening the nut a little at a time until there is some resistance when you spin the yoke. You can measure this resistance using an in/lbs torque wrench. With oil on the bearings it should take 15-20 inch pounds to rotate the yoke with no carrier installed. Its a bitch to set this but once its set the pinion nut should not be tampered with because if you move the pinion nut either too lose or tight you are ******* up the preload. When you change the pinion seal you have to remove the nut, smart people will mark the nut and the pinion shaft so that when you retighten the nut you put ot back exactly where it should be. Whinning rear on decelleration is indicator of too loose of preload. When I install pinion seals I mark the nut and tighten it up to or ever so slightly past the mark.

zaner

iTrader: (16)

If you were asking me Alamantia, it does really occur on either acceleration or deceleration...only when I get up to or maintain a cruising speed of 50 mph or better....the noise never gets louder if i mash on the gas or anything. It is a relatively mild humming sound that maintains its sound and intensity at cruising speed

hlaalu

iTrader: (3)

It seems to whine regardless at this point. It is very loud at low speeds, say if I pop in the clutch and cruise to a stop from 20mph, or if I slowly speed up it whines as well.

00pooterSS

iTrader: (40)

Something is wrong, you should NOT have a whine after any of those repairs, it is very easy to mess up a pinion seal install, there is a thing called a crush sleeve that keeps tension on the pinion bearings, alot of guys are unaware of this that have never done anything with a rear end and will over torque the nut on the pinion yoke thinking that its just supposed to be real tight, well thats not how it works and will end up damaging the bearings and the rear end will need to be rebuilt, if I were you I would take the car to the shop and tell them what happened, then take it to an actual rear end shop to be assesed for what was done wrong and have the bill sent to the original shop. I say that because most mechanical shops do not have the proper equipment for setting up a rear end and most likely damage has already occured.


I learned about crush sleeves and how easy it is to go wrong with one many many years ago after a coworker tightened a yoke nut with an impact after doing a pinion seal, the rear end failed very shortly after.

add this and what alamantia said together and it explains it all, also he said mark the nut, I mark the nut and count the threads... same thing really just stating how I do it

above spartan said if they were stock gears set back up they may whine a little, being used has nothing to do with it, they only whine when setup incorrectly new or used. besides you dont do a new setup when changing the things he had changed.

Johnny-LT1-runner

iTrader: (15)

If they removed the gears it's highly likely that they didn't set them back to spec, which might have been from them using new spacers or if they used the old ones they might have left one out.

01ssreda4

iTrader: (96)

Fresh pinion bearings should be set to 20-25 inch/pounds. However, on a used rear end they are nowhere near that and thats not what used bearings should be set back to. Thats for new bearings. Used rear ends are VERY easy to spin. 25 inch/pounds is pretty firm on new bearings....big difference. The marking the nut crap may in fact work, however, once you have done this a few times it can be done by feel. I wonder if a new crush sleeve was used or did the shop reuse the old one?

hlaalu

iTrader: (3)

wanted to give you guys an update:

rear is whining louder than ever, it's louder than my dumped exhaust lol. Called up the shop and they said it might be the pinion bearing because they just changed the pinion seal. So I'm dropping it off tomorrow morning, we'll see. sigh.

SS SLP2

iTrader: (8)

With that auburn posi DONOT use any syn oil as it will allow the clutchs to slip use only 80-90 regular gear lube and add gm additive (2 oz= little noise, best grip, 4 oz =less noise, less grip) as per SLP suggests for the Y2K with auburn
ps I do not think this will help your problem now, but think it would be correct after problem is corrected

my $ .02 Johnny

01ssreda4

iTrader: (96)

Hopefully they get you fixed up

hlaalu

iTrader: (3)

Well just got a call, they want $600 to fix a pinion bearing, some other pinion stuff, my other axle seal is apparently leaking, and my gears are scored. that is the price without a new set of gears. soooooo f-that. i'm going to try to look for another 10 bolt these next few days and if that doesn't work i guess i'll go 9"