Anyone know of a good shop in the conroe/spring area that can diagnose if the entire rear differential needs to be replaced?

I have a 98' WS6 with almost 73K miles on it that won't hold fluid in the rear. When on the lift you can see that its just spraying all over the back end. I haven't drove it in almost a month, waiting to figure out what to do. Ive been searching all over here and can't find too much info. Is GM the only place to go to get a decent replacement? Anyone else had this issue?

 

If it's spraying out its more likely your pinion seal that is gone bad and will need to be replaced.

 

Texas Auto Gear is on 1488. He's done cars for a few people I know, no complaints.

 

Probably just a pinion seal but a failing pinion bearing can also cause a seal leak. It's a 10 bolt may as well start planning on upgrading rearend depending on what you use the car for.

 

I was planning on upgrading, but haven't looked into it enough, It is my DD as of now, so right now its lots of city driving. Ive looked at changing the rear end but still not certain.. its a 6speed and I'm still learning a lot as far as upgrading, mechanical work ect. I was taught to drive a standard and have never owned a auto.

 

Ive driven past them many times and always see off road vehicles, they do ls1 work too?

 

A diff is a diff. That same crappy 10 bolt can be found in the S10 as well, so it shouldn't be a problem. And I agree, if it's spraying, the likely culprit is the pinion seal.

 

It Is the pinion seal mine went out as well. It is simple to replace yourself, use a impact gun with a 36mm socket to remove the bolt from the yoke, then the yoke slips out of the pinion seal. Use a small flat head screw driver to remove the old pinion seal.

When re installing the pinion seal it is extremely important that you DO NOT use an impact gun, use a wrench otherwise Over tightening the yoke can crush the carrier bearing and destroy your rear end.

I did mine myself because literally every thread about a shop changing them resulted in a grenaded rear end from them re tightening with an impact gun

Autozone rents all the tools you need free btw

If you absolutely can't do it yourself be sure you watch the technician when he installs the nut on the yoke. Specifically watch to make sure he tightens it manually with a wrench and not with an impact gun

 

Im in the woodlands and have a lift in the garage and we could have a seal replacing gathering?? Get enough of us together and we can change a lightbulb

Haha did nit realize it was you storey. On the phone cant see the sig pic. We had the G8 at ammco and relized you worked next door.....i would not take it next door they screwed up the G8

I have nit taken the 98 rear out but I did a 82 rearend once and like I said we should be able to get enough people together.

 

Check to make sure the diff vent is still there. It is on the passenger side of the center section of the rear axle, on the front side.



It missing, the part is $8.xx from a dealer. I hit the metal around the hole with a punch a few times, and super glued the new one in.

 

Great thread, my pinion seal leaks when the car is parked. For people who don't have a lift and are smart enough to know they are not handy, how long should the job take? This way I/we can judge how much to pay a shop. Great tip when reinstalling the bolt.

 

interesting stuff. Just need to get it looked at first I guess, then order the parts.

 

You will need to drain the rear diff first so plan on spending $7 a quart for 2 non synthetic 75w90 gear oil. If you have a 98-99 car with the LSD diff you will need to grab the LSD diff additive.


There are 4 11 mm bolts holding the ujoint on the drive shaft to the rear end. After removing the bolts and sliding out the driveshaft you will be able to access the nut on the yoke which is a 36mm bolt.

If you still have stock exhaust you may need to remove it first, with my true duals I could remove the drive shaft without taking anything else out. You may need to wiggle the ujoint to get it out of the rear end or lightly use a wrench prying from the center to pop it out of the yoke. After the u joint is freed the drive shaft simply slides out of the transmission.

Time table I think was around 3 hours. Most difficult part was re installing the pinion seal evenly in the rear end. I think I used a rubber mallet with a piece of wood on the seal to gently tap it into the rear end evenly.

The seal has a Wierd inner O ring that is like a spring. Visually my new and old pinion seal were identical so I placed the old Oring onto the new pinion seal ontop of the other one to create more tension around the yoke. Mine was obviously leaking from the yoke because there was gear oil everywhere on the under side of the car and a leak from the rear end when stopped.

I want to say I had to do the pinion seal twice because the new one still leaked a little bit, so the second time I did it I put the extra spring O ring on the new seal and it hasn't leaked a drop since

If you have a late 01-02 fbody gm changed the yoke size and it requires a smaller diameter pinion seal.

Just make sure when tightening the yoke nut you do it shoulder strength tight, and not over tightened by an impact gun. Do not try to use the yoke to push in the pinion seal. People were saying use a marker or tape or chalk to mark the yoke and nut evenly so you know where they line back up at, but I got so much gear oil on everything there was no way to see my markings. Basically the bolt gets tight enough to tell there is no way you can get it tighter. I did this right after my transmission so I want to say I put 50ftlbs on it and the nut didn't move at all so I knew it was bottomed out on the bearing. (keep in mind most cheap electrical impact guns are rated for 200ft lbs so they can destroy that carrier bearing very easily). Most mechanics say screw it and lazily use the impact to tighten it and then crush the carrier bearing.


Build your confidence and research how to remove the driveshaft. After that it's literally 1 bolt

Oh and get a hand pump topper to put on the gear oil back in the rear end. I used a new gasket from autozone for the rear end, for $3 it was cheaper and less messy to deal with than using rtv sealant to make a gasket