Advice-PROPER way to service rear diff

[Ziggyman]

Would you recommend changing over to synthetic lube? And if so, how much of the old stuff should be cleaned out first?

 

[Hydro-idi]

Unfortunately the simple process of changing rear differential oil has become too complicating and confusing.
This is a simple process. Take differential cover off, drain oil, clean oil and gasket surfaces, use new gasket material of your choice, put pan bolts back on and refill. Jacking each side of axle tubes is just a good insurance policy.
You can use synthetic or conventional gear oil.

 

[Goofyexponent]

This will "gravity feed" fresh oil to your bearings. If this step is not done, the bearings will run dry for a few miles.....which is no good. Top off the gear oil and you are all set.

I am not trying to pick a fight, but this isn't exactly true. Unless you have pulled the axle shaft out of the tube, and pulled the hub off...there is plenty of oil in there for the bearings to remain lubed.

Brake clean will break down teh oil, so if you spray inside, make sure you let it sit for a couple minutes (an hour or so) to evaporate.

I just did the rearnd in my exploder. The cover was rotten, so I replaced it. I just got two bolts that fit the threads, cut the heads off them. Put RTV on the mating surface of the diff after I cleaned it of any old silicone and oil..and put the two bolts without heads on them into the housing near the top "corners and slid the cover into place.

The two "dowel" bolts with the heads cut off will hold the cover in place and not make a mess while you put the other bolts in. Once you get teh rest of the bolts in, take the two "dowels" out and put the factory bolts in place. Tighten until you see the RTV ooze out from between the case and cover. Wait an hour before tightening the bolts up all the way. Best possible seal this way.

YOU ONLY NEED A 1/4" BEAD OF SILICONE, AND SMEAR IT OUT WITH YOUR FINGER BEFORE YOU POP THE COVER ON. WIPRE ANY GOBS OFF THAT LOOK LIKE THEY MIGHT BE TOO BIG.

MAKE SURE SURROUND THE BOLT HOLES IN RTV ON ALL SIDES, TO PREVENT A LEAK.

You don't need a gasket, I have NEVER used a gasket on a rearend cover.

 

[Hydro-idi]

I was told to do that process by a differential gear shop. He told me its just a good practice to always do that. But again, he has probably seen many bearing failures due to a lack of oil in the tubes so he just does that process with every vehicle he works on. Good insurance IMO