Leaking rear differential

[irtySanchez]

I noticed a leak from my rear diff a few weeks ago and recently determined that is coming from behind the companion flange (where the driveshaft connects to the diff. I am sure there is a seal behind the flange and also one behind the pinion bearing.

Has anyone ever replaced either of these seals? Any major labor involved or special tools needed? Would it also be a good idea to change the u joints and balance the driveshaft since they would already be off?

Any input is appreciated!!!

Thanks

 

[gijoecam]

I'm not positive, but I believe that seal goes in from the inside of the diff... if so, that would mean pulling the axle shafts and diff to change it... I could be wront, though... I've never actually worked on a diff before. (knocking on wood)

-Joe-

 

[irtySanchez]

Does anyone know if the diff needs to be taken apart or can I replace this seal from the front od the diff near the companion flange?

 

[mikeh]

I recently had the exact same problem with my 98 X. I went to the dealer and he charged me 170 to replace the rear pinion bearing and change the diff fluid. He charged me 1 hour labor so I know he did it from the driveshaft side. I didn't do it myself because I don't own a slide hammer which is what I hear you need to get the thing apart. If you tackle it let me know how it goes. I also had someone suggest to me to balance my driveshaft but I didn't do it. If it happens again I will balance my driveshaft.

Good Luck,
Mike Hill

 

[irtySanchez]

OK, I finally got around to doing this one, and here is the results:

This is a very easy job. First, drop the driveshaft by removing the 4 bolts with a 12 mm. wrench. Then I removed the companion flange with a 1 1/16 socket. Pull the companion flange off, and this will expose the pinion seal. Pull the seal out carefully (I used a flathead screwdriver and a hammer). Clean all the surfaces, and carefully install the new seal. It is a large one, so I placed the old seal over the top of the new wone and tapped around the edges until it seated properly.

While you have the shaft down, this is a good time to grease the slip yoke. I did that, put it all back together and filled the differential.

Total costs:

seal- $2.29
gear oil- 2 @ $2.29 each

This is an easy fix people, and from what I found a common problem. Don't be intimidated to tackle this one.

Good luck!

 

[Yomie]

Cool thanks, my '97 is leaking in the same spot. How much gear oil will come out when you do this? and i have the 3.73 LS rear end, what weight gear oil do i need to use (what did they use stock). Thanks for the info. Did you get the seal from auto zone?

 

[jonesyc]

Rear Diff difficulty

Okay, it sounds to me like I have the same problem with the pinion seal on the rear diff. I have pulled the drive shaft, and the companion flange. I cannot seem to determine which part inside is the pinion seal, and I am a little nervous about pulling what I think the seal is out with a hammer and screwdriver. Does anyone have a picture of the pinion seal, or give me some more detailed instructions on what it looks like. Also, is it okay to "pry" what I think the pinion seal is out with a screwdriver.