Pinion seal woes

Pinion seal is leaking bad after only 4,300 miles! Under warranty but I don't trust the local dealership to do a CORRECT job. Thus, could someone tell me the proper way to handle this issue, so I will know if the local dealer is taking the easy cheap way out? I mean, I have read some things about this and it seems like there is a lot of different ways a dealer could ATTEMPT to fix this problem. So could someone tell me what the best way to fix this issue? Thank you in advance!

Here's what I see.

1) Take it to the local one. They can't really take the easy way out. It's a pinion seal. Either it leaks or it doesn't. If they replace it and do a good job, it won't leak. If they BS you and leave it in there, or do a crappy job, it will still leak when you get it back. There's really no way to "fake' the fix.

2) Take it to another dealership. If there's no others local, make an appointment at a reputable one and make the drive. The pinion seal is a 1 hour job in the hands of a good tech. Go eat some McDonalds or something while they make the repair.

3) Do it yourself. It's not that bad. You need basic mechanical knowledge, common sense, and an impact gun. It's all about attention to detail

Your call, your car:)

Originally posted by Bone Maro
3) Do it yourself. It's not that bad. You need basic mechanical knowledge, common sense, and an impact gun. It's all about attention to detail

Your call, your car:)

Umm, I am curious.. I too found this to be an issue with my car :(

I remember doing the rear end gears on my 95 Z.. There was a bearing that had to be installed using a press.. Where is the rear seal and would this bearing be affected at all?

For mine, I am just taking it to a local dealer. Let them get it to me ASAP under warranty.. Just call and make an appointment.

Originally posted by psychocabbage
Umm, I am curious.. I too found this to be an issue with my car :(

I remember doing the rear end gears on my 95 Z.. There was a bearing that had to be installed using a press.. Where is the rear seal and would this bearing be affected at all?

For mine, I am just taking it to a local dealer. Let them get it to me ASAP under warranty.. Just call and make an appointment.

Ok. I bought my Formula, and the pinion seal was leaking. So, they replaced it under warranty. 1 month later, it was leaking again. Again, it went in under warranty. When I picked it up and got it home, I found it was still leaking. So, I got under there and fixed it using an impact wrench(the pinion nut/yoke was loose). Here's the short of it:

1) Remove the driveshaft.
2) Remove the pinion yoke nut, and the pinion yoke(this is where you'll use the impact wrench the first time).
3) Remove the pinion seal, it's a ring of material that's insdie the front of the diff(you'll see it once the yoke is removed).
4) Replace the pinion seal and make sure it's flush all around.
5) Replace the yoke and pinion nut. You'll need the impact to get it back on.
6) Replace the driveshaft.
7) Run car around a bit and watch for leaks.

That's the quick version, but it's really a bit more involved than that;)

I just had my gears swapped out on my A4 to 3.73's by a local reputable rearend shop. For $10 more they installed a "solid" pinion crush sleeve that would eliminate the seepage problem.

If you have the dealer do the job, purchase one and ask if they would use it in the install.

JMHO

SteveC :)

That is exactly what I am talking about Steve C! Thank you for the advice! I don't want what happened to Bone Maro happen to me. I want the dealer too TRUELLY fix the problem instead of attempting to fix it and it leaking again and me just end up fixing it myself because the service department provides no service at all but to prove they suck. Sorry.....So this "Solid Pinion crush sleeve " why is it different from the original and why would it work better than what they use now? It is odd that Chevrolet has displayed some sort of care to consumer opinions in regards to some things but totally missed the mark with others. For instance, my brother has a 1995 Camaro which cosmetically differs from my 2002 in regard to cup holders, middle console, and t-top leaking where they improved those things with the 2002. My point is this, that $10 dollar part GM can probably get for about 3 cents so why wouldn't they use that part if it has proven to be a better component. They seem to listen to consumers on many other issues why avoid this one? Anyway, if you could enlighten me in regard to the beauty of this Solid Pinion Crush Sleeve I would be very appreciative. Thank you in advance for sharing your thoughts and opinions on this subject!

pinion crush seal??????


mines been leaking for awjile now..........

Brian2002SS;

Here is one that Jeg's sells, even though it is not for our rearends, it will give you an idea of what the item is. Actually this was suggested to me by the rearend shop that did my gear install, and I figured for $10 more, why not:


http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=7332&prmenbr=361

SteveC :)

Stik6shift98......you have this solid pinion crush sleeve installed and it is leaking still?

Anyone else have this part installed and it still leaks?

SteveC......thank you for your help, since my car is still under warranty, can you tell me if GM has this part as a "genuine" part they can use and not void the warranty?

Again, thank yall for the help!

im saying i dont know what it is


and mine is leaking

Brian2002SS;

I do not know if GM carries this item.

SteveC :)

My 2002 Z28 has a leaking pinion seal too (apparently). I've only got 2,800 miles on mine. I get some drips on the garage floor and there is a thin film of oil sprayed in a horizontal pattern above the u-joint/differential junction...

Jfischer......that is exactly what mine did. Thanks for the info. I took mine in for service this morning and will post what they say they did to fix the problem when I get my car back.

Anyone else having this problem also please let us know.

Originally posted by Brian2002SS
Jfischer......that is exactly what mine did. Thanks for the info. I took mine in for service this morning and will post what they say they did to fix the problem when I get my car back.

Cool. If you can let me know what they did and how long it took them it would be great. I don't want to leave mine there over the weekend, and I need to time it with the weather here in Colorado so that I don't get stuck driving it home in the snow :)

We haven't had any snow to speak of all winter, but I can guarantee that if I take it in and they have it for 3 days, it'll be snowing like a *(#% the day it's done...

I will post the outcome of the service just as soon as I get my car back.

Yeah, I just got my pinion seal replaced, these cars are known for it, and I guess it's normal.

Well, the service department confirmed that it was the pinion seals doing so they "replaced it". That is all the detail they gave me. I do know that from time to time GM will post issues on something called a Mechanics "Bulletin Board" about common issues and I asked if this pinion seal issue was on that Bulletin Board and they said No. So if it starts leaking again I will post that at a later date. Hopefully them replacing it will be good enough. Good luck!

Hey,

I got a question for all those who have had pinion seal leaks. I've noticed about 2-3 teaspoons of liquid has collected on my garage floor right under the rear differential when the vehicle is parked. Does anyone else experience this volume?

I got under the car to try and determine the source of the leak, but it was so dirty that I couldn't locate it. An interesting thing to note is that it looks like some type of liquid has sprayed up onto the exhaust right near where the drive shaft and differential connect. Does this happen when the pinion seal is bad?

Also, how much can I expect to pay to have this fixed at a dealership?

Thanks!
__________________
NewRave [Brian]
2000 SS Camaro Convertible

===== SLP Options =====
Hurst Short Throw Shifter
Cold Air Induction Box
Mass Airflow Sensor
Loudmouth Exhaust
Temperature Module
4.10 Gears

I had to replace mine a while ago. You could notice drops or even a puddle of liquid, just depends on how bad the leak is. If you've got more than a small amount, you might want to check your diff fluid level before driving too far.

Question for everyone:
My diff makes noise. A lot of noise. Is there a specific torque setting for the pinion yoke nut? If so, is it important enough that improper torque would make my rear diff louder than my LT's, ORY, TSP rumbler setup? Dammit, I hate not having $2500 for a 12-bolt!!

Also, can anyone answer once and for all: when using GM Synthetic Axle Lubricant SAE 75W-90 do you ALSO have to add the GM friction modifier/LSD additive? I have had 2 dealerships tell me NO, and a hundred other people tell me YES.

If neither of these things are my problem, then I believe my rear got messed up when some dumbass 16 year old girl in a Suburban played bumper cars with my baby. :cry: She did hit the right rear tire as well as the rest of the car on that corner. :( :mad: :( :mad:

Abe

I got under the car to try and determine the source of the leak, but it was so dirty that I couldn't locate it. An interesting thing to note is that it looks like some type of liquid has sprayed up onto the exhaust right near where the drive shaft and differential connect. Does this happen when the pinion seal is bad?

Holy ancient thread, Batman! :D

If the oil leaks out onto the driveshaft or pinion, the rotation may cause the fluid to spray up in a horizontal pattern (from side to side under the car).

If you're getting any fluid on the ground near the differential, odds are that's where it's coming from. I have had no leaks at all since I posted this original thread back in 2003, so once they get it right it seems to hold for quite a while...

Question for everyone:
My diff makes noise. A lot of noise. Is there a specific torque setting for the pinion yoke nut? If so, is it important enough that improper torque would make my rear diff louder than my LT's, ORY, TSP rumbler setup?

Proper pinion bearing preload is critical! That is why you can't just replace the pinion seal for a proper repair. Reason: there is a crush shim between the 2 pinion bearings. When the nut is torqued, it slowly crushes it till the bearings start to put pressure on their races. This starts to preload the bearings as they push harder against their races. It's not like front wheel bearings where you tighten them lightly with a wrench, then back off a bit, pinion bearings are actually squeezed.

Proper preload is ~ 24 in/lbs with new bearings, ~ 8 in/lbs with used, if memory serves. Been a while since I've done a diff.

Reason you can't just replace the seal: once you crush the shim, that's it. If you over crush it, you can't just back off, needs a new one, cause it's sprung. So the one that came in it from the factory can't just be reused. In order to put in a new one, you have to remove the posi carrier and pull out the pinion.

In order to properly do the preload setting, you have to install a new crush shim, install only the pinion gear, and torque nut till the slack is gone. Then you put a dial in/lb torque wrench on it to check preload. You alternately put more torque on it/check it, till you sneak up on proper preload setting. Then you reassemble the rest of the diff.

You can get away with just replacing the seal sometimes, but the possible consequences of doing it wrong include howling noises from the pinion bearing being over preloaded causing them to be destroyed, being under preloaded causing them to not be properly supported and failing, like an under torqued rod bolt.

Solid shims replace the crush shim. You pop it in there and torque it to a set value. Check the preload. Too much preload, and it needs a thicker shim, too little and it needs a thinner shim. The pinion gear needs to come out in order to do this.

Angel, thanks for you reply and info. "Howling". That is the exact word I would use to describe the noise my rear diff makes. Dammit.

Abe

Angel, thanks for your post--can you provide a little more clarification? I've read a lot of posts that recommend replacing just the pinion seal in order to fix a leak from the rear differential. Is it your opinion that even if this is done at a shop, it's the wrong approach?

Thanks for your help!

Keep your eyes peeled on the LSx boards for 12 bolts. They come up once in a while and you can save a few hundred. Board sponsers will sometimes sell them new for a couple hundred less on specials. Check the sponser sections of the boards.

As far as your lube question, I put just the synth lube when I replaced diff fluid, no additive. Valvoline I think. No chatter. There will be no possiblility of damaging anything if you don't use the friction modifier. If it chatters around corners, you can buy some and throw it in, if it doesn't chatter, no problem.

Heads up: when an axle gets hit (crash or slamming a curb) a lot of times it will lead to the infamous broken retaining bolt on the pinion (spider) gear shaft. This happens cause the force of the impact travels up the axle, the axle hits the pinion shaft, the shaft hits the little bolt and breaks it. A bear to get that broken little bolt out. Your axle might be bent too.

I've read a lot of posts that recommend replacing just the pinion seal in order to fix a leak from the rear differential.

You can just have the seal replaced, but it's not the proper fix due to the need to preload the pinion bearings properly. It's a quick fix. You can get away with it, or you might trash the bearings. When I was a kid my dad did the quickie fix on our 57's diff. It crapped out about 3 months later. Those diffs have a drop out pumpkin, so a trip to the junkyard for a pumpkin out of a 61 and it was good to go. I still have the 57 btw. ;)

A good shop with the necessary equipment can do the proper repair in a couple of hours. Jmo.... and every diff I've ever worked on, whether a seal or a gear change, turned out fine, no grenade action. :D

I had the dealer replace mine 3 times,each repair lasted about 6 months.3rd time they contacted Chevrolet & there is apparently a problem with some of the yokes that are causing the seals to wear & fail.They replaced the yoke & seal last time & it's been fine since,which was over 2 years ago.

For all you guys that have new seals leaking after a few hundred or thousand miles:

Check for a groove on the pinion yoke where the seal rides. I had a new seal leak something fierce and found the seal surface had a SLIGHT groove worn into it. I replaced the pinion yoke and seal and no more leak. It can also be speedy sleeved but you need the exact diameter of the pinion yoke seal surface to get the right size speedy sleeve. GM has the kit with new yoke and seal (updated double seal design) for about $100.

Also if you do it yourself use a sealer on the yoke splines during re-assembly. Gear lube can migrate out the splines and leak around the pinion nut.

Last note -- if you have a crush collar and zap the pinion nut on with an impact gun you can crush the sleeve too much and destroy your gear set-up. I can't remember the details of how to retighten a crush collared pinion nut as my 10-bolt had a solid spacer after the 2nd rebuild and the DTS 12-bolt came with a solid spacer set-up. Try a search on pinion seal leaks.