Differential Service

[tigerKJ]

So I am looking at lifting my '02 Liberty Renegade and was crawling around underneath. I have leakage around the pinion seal on both front and rear differentials. So before I lift and go off road I want to get this fixed. What I don't know is when was the last time the diffs were serviced.

I saw the sticky on doing the pinion seal, but I was thinking of having a full service done. What does a full service include? I was thinking it includes all the bearings or is that an overhaul kit?

I have 153k miles so maybe it would not be a bad idea to do an overhaul, the kits seem reasonably priced (~$160 for the rear - but the front seems expensive) and I would get all the bearings, new seals and gaskets, and other parts (not sure what they are).

If I do the overhaul what else should I do to make the diffs mechanically sound?

Along with my lift I am planning 245/75R16 tires and was reading the chart posted in the sticky, should I put in 4.10s/4.11s or just leave my 3.73s in there?

Thanks!

 

[M38 Bob]

If you don't have clunking/whining/slack,,, leave them bearings the hell alone!! Pull the diff cover to drain the rest of the oil, use a can of brake cleaner to flush. Follow sticky instructions for seal change, install diff cover, fill with appropriate lube, and buy yourself a beer or six for a job well done.

Bob

 

[tommudd]

I would swap out the fluids on the front and rear diff, along with transfer case , clean everything very well, then watch it to see if there is actual leaks or not
If there is then proceed, could have some bad seals or could be coming from somewhere else

 

[tigerKJ]

OK, drain and replace fluids and power wash the undercarriage. Then I'll watch for leaks and track down where it is coming from.

If still leaking from the pinion seal, then I'll replace.

Do you ever clean and grease the bearings or just leave them alone until they make noise? How do you check if your bearings have slack? Is that where I lift a side add see if I can pull and push the wheel in and out?

 

[M38 Bob]

OK, drain and replace fluids and power wash the undercarriage. Then I'll watch for leaks and track down where it is coming from.

If still leaking from the pinion seal, then I'll replace.

Do you ever clean and grease the bearings or just leave them alone until they make noise? How do you check if your bearings have slack? Is that where I lift a side add see if I can pull and push the wheel in and out?

Get a couple good, clear pictures of the seal area and post em here. Pretty easy to tell if they're leaking, or being leaked on if you know what each looks like.

"Clean and grease the bearings". No, they lube from the grease in the differential(when one has an axle shaft in hand, if you look closely you'll see tooling/lathe marks that look a lot like really fine threads the entire length. These act as mini augers to carry grease to the bearings), and the clean part is why you change the grease.

In and out play is the "C" clip at spider gear that holds the axle in place. Not an issue. Up and down play is an indication of bearing/axle shaft wear. Large part of the time, if the bearings have any appreciable up and down the axle is worn also.

Bob

 

[tigerKJ]

Thanks Bob!

I'll post pics as soon as I get back under there.

 

[tigerKJ]

Haven't had a chance to under my Jeep again, but I was wondering about gearing.

I currently have 3.73 (the diffs still have the tags on them plus I got the build sheet). Since I am going to lift and put bigger tires on I was wondering if I should get 4.10 gears for the diffs. I am planning 245/75R16 or 265/70R16 for tire size.