Do I need a new diff cover gasket?

So I just bought my 2000 Cherokee from an older couple who serviced it on time and were very good about caring for it. It has 88k so I figure I will need to do a differential service within the next couple thousand miles. I'm sure it has had regular coolant flushed so I'm more worried about the diff. The gasket in between the cover and the casing right now is orange and there is lots of gear oil on the bottom and behind the diff. It may even be dripping (saw a few spots but not sure if there from me) and I would like to address it soon. I wiped off the bottom and behind just a little bit to stop any dripping. Do you think I need a new gasket? Here is a picture.

Looks more to me like it needs a new pinion seal. It is a low pinion dana 30 front end, so you will need a new crush sleeve and a torque wrench to install it.

Parts:
* new dana 30 pinion seal
* new low pinion dana 30 pinion crush sleeve
* new dana 30 pinion nut
Tools:
* inch-pound torque wrench capable of measuring approximately 10-20 inch pounds
* regular wrenches, sockets, etc (I believe the dana 30 pinion nut is a 1 1/8)
* 12 point 13mm or 1/2" socket

You will need to pull the carrier to properly set the bearing preload on the pinion (10-20 inch pounds with used bearings) which also requires pulling the axle shafts and hub bearings. It is not that bad a job but will definitely be a learning experience.

I'd make sure the bolts on the cover are tight. But if your gonna service it anyway, just do some more rtv like what is on there now or get a lube locker? gasket.. The pic looks more like a pinion seal leak to me though.

So you guys think it is the pinion seal? How long does it take to change assuming I don't run into complications?

Since you have to pull the axle shafts and carrier out, I'd give it about a 3-4 hour estimate - the first time. It's way easier once you've done it a few times.

Also, there appears to be little rust on that axle housing, so it shouldn't be difficult to get the hub bolts turning. Those can be a real bear on a rust belt axle.

Alright great thanks for the advice. I'm contemplating having a shop do it I'm pretty scared about getting the sleeve/nut perfect. Any ideas how much they would charge?

If you're gonna wheel it, the LubeLocker gaskets are invaluable. Changing shafts is so much easier on the trail, and u can reuse them to get home. I had no leaks the first re-use, but after the second, she drips a little. Now it matches the other 2 spots in my garage. =no RTV to scrape off or goop on.

jamesonw23 said:

Alright great thanks for the advice. I'm contemplating having a shop do it I'm pretty scared about getting the sleeve/nut perfect. Any ideas how much they would charge?

Click to expand...

Probably enough that you could swap in a non leaking High pinion for less money. Are you planning on wheeling it?

x4 on the Lube lockers. Had mine off a half dozen times now, only minor seepage.

Yea I'm planning on wheeling it. Just light wheeling though nothing too serious. And I'm working on getting my lift right now. Is the pinion seal something I'd be alright with putting off for a little while or is it crucial that I get it done right away?

No worries, just top the diff off with gear lube once in a while. I ran mine for nearly two years like that and it still had plenty of fluid in it when I removed the axle because all the control arm brackets ripped off (too much rust.)

You can pick up a high pinion d30 with stock gears for like 100 bucks on the classifieds probably. They are better for wheeling (better clearance and driveline angles) and if you are going to regear this method lets you get the axle regeared when it's not in the vehicle (cheaper) and then install it whenever (less downtime.)

What he said....

x2 with Kastein. The HP 30 design is a little stronger, and accepts lifts easier than the LP. Your pinion seal isnt submerged in gear oil, the slinger just throws some up there to lube the pinion bearing. So the leak is minimal, and I wouldnt worry about it immediately. My suggestion would be: Run it as it is. Look for a HP D30 in junkyards or classifieds. When you finally come across one, buy it, then set it up for whatever your goal is. You can swap everything from your old LP to a new HP. See if you can get it cheaper for bare bones (no knuckles, hub bearings, axleshats) You can reuse everything from your old axle. It would also be a good time to throw in some 760x u joints in the shafts, and check the unit bearings. Then, when u put a lift on it, just drop out the old axle, and put in the new one. I mean, everything's coming off anyway (coil springs, shocks, contol arms, tie rod) it would be a perfect time to install a new axle. A junkyard HP D30 is $100-$200. New Spicer 760's can be found online for about $25 each. Just my suggestion (Hindsight is always 20/20)

X2. Another thing I just remembered - when you buy your HP donor axle, try and get one with the newer style unit bearings (99.5 and later, so basically you are looking for a late 99 donor vehicle) because that way you have a second set of shafts with compatible unit bearings preinstalled to use as trail spares. The 99.5-01 dana 30s all used the new design. You could also swap to older style brake rotors and use older style unit bearings, but this means you won't have a set of spare shafts on hand as a side effect of getting the new axle.

Forgot about the hub bearings, which is especially ignorant considering I just put new Timkens in 2 months ago. :eyes: Mine's a 2000.