I had to remove mine because I was loosing fluid (weeping) from the bottom of the cover. I have changed my fluid at 55k, 80k, 103k and now pulled the covers at 128k. It feels completely different when the cover is pulled and cleaned. I have access to a parts washer and used that to get it completely clean, then I cleaned up the edges and the outside with a wire wheel brush, primed it and sprayed it a nice flat black. Looks great and drives even better than before. If we had a few beers at a bar right now, this would be the time I would say to pull the covers and you be the test for this.

I said it before with adding a new ground wire. "the jeep sounds like it starts better." Same thing again here. "It seems like it rolls much easier and is much quieter." I know it all sounds crazy but I really find it to be slightly better than just adding in new fluid. My girlfriend has a 2004 grand cherokee and I did her diffs last night and she called me this morning to tell me exactly the same. Hers was 109k and the fluid was from the factory but still.....

My advice would be to pull the covers 1. with any sign of a leak 2. every 100k.

I'll buy you a beer if you are willing to be the test pilot. I'd love to know honestly. Im the type of person who thinks they can feel a difference with new oil, air filter spark plugs ect...

 

I always take that opportunity to check my gears and lockers, a lot of stuff can be caught early with a simple inspection and it's one tube of RTV for both covers.

 

Maybe I'll take you up on that. I'm 50 yrs old, but my 2012 jku is the only brand new vehicle I have ever purchased. I keep meticulous records, including every single gas full up. I have 95,000 miles of mpg data in an excel file. Maybe when I hit 100,000 I'll treat the Jeep to some additional maintenance including removal of the diff covers, spark plugs, and coolant flush. This February will be my 6 yr anniversary with it and it will likely be hitting the 100k miles about the same time.

 

Definitely time for a coolant flush.
Add a brake fluid flush to the list, if you haven't done one in the last few years.

 

I didn't flush the brake fluid, however when I changed front & rear at 70,000 miles I compressed the pistons at all wheels, then I siphoned out all brake fluid that was in the reservoir and filled with fresh fluid. I'm not sure how much that replaced, but must have been a decent percentage.

 

I would still do a complete flush every few years.
One of the problems of not flushing the system often enough is corrosion. A typical symptom is caliper seizure right after a brake pad change. The piston is forced back into a position it has not been for a long time. Corrosion in that part of the caliper bore can cause the piston to stick.

I'm on my 3rd set of rear brake pads with the original calipers. I believe timely flushing has prevented corrosion in the system.

The service manual says the flush should include cycling of the ABS pump, so I have been having the dealer do it.