I bought a new 3.90 diff off a forum member but it had been sitting around for a while in his garage and has some dirt and contamination inside. How should I flush it out? My current options are:

1. Use Kerosene and pour it through the diff
2. Use a mixture of 50/50 kerosene and oil and pour it through the diff
3. Clean it up as best as possible and install it. Then change the diff fluid after 10 and 50miles.

Note that this diff has new gears in it.

 

Anyone???

 

I would just go to Autozone and get some cheap brake cleaner, it evaporates quick and leaves no film behind. I also am assuming this is for you C5? There are alot of passages in those centers, so you might want to take off some covers and clean it out completely. Let it dry and put your oil in and roll it around to get il back into the bearings.