When to do a diff rebuild
 

I have a 4.88 factory gear 8" about 180k on it. I noticed it's been leaking gear oil and replaced the pinion seal. Now it doesn't leak as much... I need help figuring out what's wrong with it.. If I need to buy a rebuild kit or is it something simple.

Just read a thread in here I didn't grease the seal and I honestly didn't replace the gear oil when I did the seal

Where is it leaking? Pinion seal or where it bolts to the housing?

Pinion seal. Should I redo the pinion seal torque to specs?

Does the pinion have any play in it? If it doesn't then you should be set with just a new seal.

Actually I was just going off of memory pinion seal is fine it's leaking from housing

You will have to pull the 3rd just use rtv to seal it. There are several write ups on how to do it.

While you have it out to reseal it and have the tools, you could check it out, along with your axle seals and rear bearings.

Look at gearinstalls.com for info.

RTV that bugger....Attachment 137777

Also check your breather.
If it can't vent properly it will build internal pressure and cause more leaks. It's best to unscrew the breather from the axle and clean it from the inside because they can get clogged.

Breather is perfect I've checked it. Planning to reseal it this coming Friday when I'm free do I have to take the e brake and drums out ... Or can I just take the 3rd

You have to pull the axles out about 4 inches to be able to remove the 3rd. You can do that without removing the e-brake, but be careful to support the pulled out axles so they don't rest on the axle seals and damage them.

You'll need to disconnect the brake lines, and remove the 4 nuts holding the brake drum assembly to the axle housing. Then just carefully slide the axle out far enough to allow the 3rd to come out. The 3rd is heavy - either get some help or use a jack.

Hi Ed----
Pull that diff and send it my way :)
You have the factory 488 diff and that has some good value......once the ring and pinion get destroyed/damaged then you might as well throw the whole rear 3rd in the dumpster and start over with a new 3rd. The 488 3rd is "unique" and aftermarket gears won't set-up inside it.

It sounds like your 180,000 mile bearings are getting worn out and getting loosey goosey. Time for a 8" V6 master install kit which has the 4 required bearings and other stuff.

Not a job I would recommend to someone without the specialized knowledge and the tooling.

And RJR has a good simple idea....just slide those axles out about 4 inches and the 3rd should come out. That way you don't have the messy brake fluid to deal with and no break bleeding afterwards.

I've done that before....I did take the drum off to make the axle assembly lighter......I removed the brake line clips located on the top and backside of the axle housing(there is about 5 of them)....it makes stretching the brake lines a lot easier and less damaging to the factory bends. I also supported the axle ends with jackstands or similar to prevent the heavy axle assembly from resting on the delicate axle seals.
Ken (ZUK)

Oh dang forgot these are unique and aftermarket won't set up in it! Thanks for the helpful information Zuk. I'll keep it updated as to if I run into any issues

I only have some play between the differential and housing should I disconnect brake lines and just bleed them. I'm 2.5 inches pulling out the brake drums and It feels I can't go any more..

Took out the brake line pulled drums farther out and all seems well. Sealed up no leaks. Thanks for your assistance everyone