Rear Pinion Seal info needed....

[mikesoc82]

i have a 1996 3.8 v6 5-spd.. does anyone have detailed instructions on how to replace the rear pinion seal?? and is it so much of a headake i should just bring it to the shop.. how many hours am i lookin at...

[camaro28]

how much of a leak we talkin here? Just a few drops on the garage floor? Or puddles? All 3rd and 4th gen rear pinions have a real shiddy seal design, its just something we gotta live with.

[mikesoc82]

when i first got the car anytime my foot was off the gas the car would brake almost as if my foot was in the brake.. but it wasnt, i figured it was the stick slowing the car down in gear.. it was the differental fluid level being to low..

its been 1,000 miles since i filled it up and its about an inch+ below where i filled to... my drive shaft is soakked in the stuff (is it just me or does differental fluid smell like bad mexican food?)

im pretty sure this is why the car was put up for sale... so whatever im dealing with im sure wont be pretty... but im ready for it...

but even in my haynes manual it has nothing for the rear pinion, it has the cover gasket but im lookin for good detailed information about the rear pinion seal... any information anyone has or stories about there experence with this mess would be great..

[hockeyman]

Sounds like it's leaking a little more than what is considered normal to most of us here.
I have a drop or two every few days, but I'm not gonna replace it until it get's worse.
I would personally take it to a shop to have them replace it. There are certain measurements/shims that need to be met when installing the seal, and I don't have the tools or know-how to perform the task.
If you do take it to a shop, expect to pay at least $300 to get the job done. BUT, don't be surprised if it starts leaking a drop or two like mine within a month or so. Because like camaro28 said, they really do have a shiddy design.

-Marc

[ July 01, 2003: Message edited by: hockeyman ]</p>

[speedy-v6-camaro]

<blockquote>quote:</font><hr>Originally posted by mikesoc82:
but even in my haynes manual it has nothing for the rear pinion, it has the cover gasket but im lookin for good detailed information about the rear pinion seal... any information anyone has or stories about there experence with this mess would be great..<hr></blockquote>

I'm pretty sure the Haynes manual does have the procedure to replace the pinion seal. It only cost me $65 to get it done at the dealership.

[BillyCobin]

My Haynes has the correct procedure.

Mine was leaking and I replaced it myself, but I didn't do it to exact specs. Here is how I did it.

1.) Unbolt the drive shaft from the pinion.

2.) Get a big socket (something like 1 1/4 or 1 1/8, can't remember exactly, about 6 bucks for a craftsman), hold the pinion yoke (the part the drive shaft is attached to) in place with a large slip joint pliers. I held it in place by putting a large screw driver between the yoke and torque arm (big black thing running form the transmission to the diff housing). Count the number of threads showing past the pinion nut, and make a mark on the pinion nut and on the pinion so you can line the nut back up. Then remove the pinion nut.

3.) Use a gear puller to pull the yoke off of the pinion.

4.) I already had a seal puller (looks sort of like thoes things that rock climbers use that they shove into ice, they are about 7 bucks at AutoZone), and I used that to pry out the old seal. You might be able to use a screw driver, but it would put extra stress onto the pinion.

5.) Clean up the pinion yoke, pinion threads, nuts, bolts, and the place where the seal sits in.

6.) I coated the OUTSIDE metal edges of the new seal with Permatex number 2 sealant. Now you are supposed to use a seal driver to push the new seal in straight, but all the seal drivers I could find wouldn't work for this application. So I just put the new seal into place, and slowly tapped it into the diff housing with a hammer.

7.) Now rub some of the gear lube that has spilled out onto the rubber inside of the seal, and rub a little on the pinion yoke, and slide that bad boy in. Becareful not to damage the rubber seal.

8.) Now comes the pinion nut and washer. I put Permatex on both sides of the washer, and slid that onto the pinion. Then I coated the pinion nut threads with Permatex lock-tite (the red stuff, because it's all I had around).

9.) Put the nut back onto the pinion, tighten it until you the marks you made earlier, and the number of threads visible before, are visible again. Then, I tightened it down just a little bit more.

Now, by the book, you should have used an inch-pound torque wrench to figure out the preload on the pinion, but Sears wanted 80 bucks for an inch-pound wrench. If you over tighten just a little bit, the worse thing that will happen is that your gears will whine a little bit. Mine already whined before I replaced the seal, so I didn't notice any diffrence.

I also drained my diff fluid at the same time, so here is my parts list for the project.

Diff cover gasket - $3
Pinion gasket - $8
Pinion socket - $6
Gear puller - $10
Seal Puller - $7
Permatex #2 - $3
Lock-tite - $3
2 Qts Synthetic Mobile 1 lube - $10 (I think, can't remember)

Total: $41

So, if you had no tools, it would be $41, just the parts are $17.

I had the tools, so it was a pretty cheap fix. It sounds like your gears have been through a lot, so it might not be a big deal to you to get the preload exact. Plus half the shops you take it to probably arn't going to check the preload anyways. But, if you could get it fixed for $65 bucks it might be worth it to have a shop do it if ya don't like working on stuff much.

As far as the seal design, I think the design is just fine. They used the same design (like camaro28 said) from 82 until 2002. They also use the EXACT same design (it might be the same seal too, not sure) for the seals on both the input and output on the transmission. Not many people have the input seal on the transmission leak. The pinion seal is exposed to all kinds of weather and abuse, it's just in their nature to wear down and leak after a while.

[mikesoc82]

my gears have probally been thru hell.. when i filled up my fluid last time my rear was way to hot.. should i take the cover off.. replace that gasket while im down there.. and replace my gears while im at it.. i got a feeling they have been thru alot of abuse with low fluid levels...