TN_Vol_Jeeper

So I just changed the differential oil myself for the first time. Stock JK Sport diffs. It's a really easy process, however, when filling the diffs back up I could only get 1 4/5 a quart in the rear and 1 quart exactly in the front before the oil started spoiling out from the fill holes. From everything I've read, the rear should be taking close to 2.5 quarts and the front should be taking nearly 1.5 quarts. I definitely drained then dry before plugging up the drains and filling. Anybody know if those amounts sounds normal/okay, or if I need to pull the covers off and see what's going on.

14Sport

Do you have a lift? If so, the difs are tilted and the stock fill holes are too low. That's why aftermarket covers come with higher fill holes. You could try parking up hill or jack the axles if you do.

TN_Vol_Jeeper

No lift. Stock suspension on true 33.1" tires, but of course that won't affect any geometry. Thanks for the suggestions though.

tjkamp

Differential fluid is much thicker than other fluids, you likely will not get all of the old out without removing the covers, and giving it a thorough cleaning, that's just how it is. I would say after filling them up make a few laps around the block, and then let them cool for a couple of hours, or over night, and then check the fluid level again, if it still comes up as full you are good to go.

It has been several months since I did mine, so I don't remember exactly how much they took, but it was less than the manufacturer's specs. I haven't had any issues yet.

lowendrider

X2...mine took less than recommended as well. Recheck for peace of mind..all is probably well.

TN_Vol_Jeeper

Thanks guys. Only place I'm going tonight is to the gym a few miles down the road. I'll check it out tomorrow morning. I have a spare quart now that I planned on using today. If they need it, I'll throw some in there.

rob_engineer

I've changed my fluid twice. Had same experience as you. The capacities listed are what it takes to fill a new, dry system. You never get it all out. It goes all the way down the axles. You did it correctly and have nothing to worry about.

TN_Vol_Jeeper

If this is true then I think I definitely need to take off the covers and clean these things out. I also need to go have a talk with the Jeep dealership here in town. I've had them "change" the differential oil every other oil change since I've had this Jeep. Actually only been 6,000 since the last time it was "changed", but when this stuff came out it was like thick, gloopy tar. I'm almost positive that those crooks have been charging me and haven't changed the stuff the past couple of times, if ever. I've never seen differential oil look that bad, even after trucks that I've let go 20,000+ without a change.

river2c

The oil in the rear axle flows into the axle tubes to keep the outer bearings lubed. In order to get all of the old oil out, you need to lift each end of the axle up off the ground a few inches (separately) and let all of the dirty oil flow out. Removing the covers and manually rotating the gears will get even more out. Just make sure you check the oil levels after you have driven it a few miles and you should be fine.

kik

Like others have said, you can't get it all out and it's not a dry fill so you filled it properly. I don't do my diffs until 15,000 miles. The Mopar standard gear oil will basically look like you described after only a few thousand miles. I really don't see the need to change it at 6,000 miles. The dealer probably drained and filled it and charged you a ton of $ to do it. You're better off getting synthetic gear oil 75w90 or 75w140 for the rear if you tow, and 75w90 for the front and doing it yourself. It's easy to remove the covers, clean it out, and use Lubelocker gaskets. If you have limited slip most if not all of the synthetic gear oils have the limited slip additive already in it, it will indicate that on the bottle. If you don't have limited slip you can still use it, it has no effect on an open dif.