63,200 miles - should I be doing this?

Gear oil smells really bad if it has been mixed with water. At least that has been my experience.

Check your breather hose for cracks and make sure it terminates higher than any water you might cross...

Anybody KNOW: If the factory trailer tow pack is installed at factory during new build (like my JK): Is 75W-90 OR 75W-140 instead filled in the rear??

yes. If you have never done it, it is time to do it.

IIRC, 75-90w is the factory fill regardless of the tow package option. I can't find my notes on the source of that information though. I believe it was partially due to the fuel economy ratings that 75-90w was determined at the factory.

Holy moly.

I change mine at every other oil change; front is usually nice and pretty but the rear always looks hell.

And gear oil always smells rancid. A sweet death-like odor. Nothing gets my wife out of the garage better.

Im curious, are 15k-30k diff oil changes really needed? I know a guy with a Cherokee who hasn't done his diffs since his 150k miles service, and he is a little over 250k miles now. He's only changed he oil twice since he bought it.

You can't get better than Amsoil Severe Gear. I'd feel comfortable changing it only every 75k.


AMSOIL - SEVERE GEAR® Synthetic Extreme Pressure (EP) Lubricant 75W-110 (SVT)

I'm sorry but I would not use Amsoil in any of my vehicles . We used to have a B-sports racer ( A Chevron , Scotish built ) and were talked in using Amsoil . The results cost us an engine and an "Oh couldn't have been the oil" from the Amsoil guy . The bearings on the crank failed right by the oil pump feed ......... this never even showed wear with our normal Quaker State or Pennsoil ........... For me never again in anything . My $0.02

Sorry, I don't buy a bit of it. Ever had an analysis done on this stuff? You couldn't find a stouter Gear Oil if you spent a week looking. As for the motor oil that you think failed, does everyone that races and has an engine fail blame the oil, or does the fact that they were racing have anything to do with it?

I've met a person that claims to smoke 3 packs a day and drink a quart of Scotch; she's the grandmother of a nurse I know and is nearly 100 years old. She's perfectly healthy and takes no medication.

But I don't think it's recommended; it would kill most people.

And, fwiw, Amsoil is a fine product with a long and glorious history of passing muster with mass spectrometer data sheets to prove it.

Everything that you'll ever want to know about oil is covered in THIS FORUM

What about royal purple, anyone hear anything good or bad?

Just did the fluid change. Took an hour because I was nervous but when the dealership told me that it was going to cost 359.00 bucks, I thought it was worth a try.

I put 75W/90 in the front and 75W/140 in the rear. I did a simple drain and refill in the front and then a thorough change in the back.

I could only get 1 QT in the front before it oozed out and 2 QT's in the back. It was a serious pain in the arse to not have a pump. Next time, I will and it will be much easier.

So, should I check it again since I only was able to to get 1QT in the front or is that normal? Being that I didn't get to take the cover off and do a more thorough job on the front, I am wondering if that is why I could only get 1 in there.

Thoughts?

I did my diff fluid change today, and the same thing happened to me 1Q in front and 2Q in rear.
So what did you find out, did you refill it some more later on????

I figured doing one of these diff oil changes was self explanatory and figured it out myself, however I didnt know which diff oil to use. I decided to go with 75w90 synthetic Mobil 1.