I would like to put a aluminum differential cover on my truck, most likeley one from summitt racing. I have a 98 f-150 off road with 97,000 miles on it. I have heard that I can cause more damage messing with the differential with high miles. Is this true ??? I have those sweet Rancho RS 9000 shocks and would love to dress up the differential as well. Any input would be great.

 

Changing the rear end cover does nothing detrimental to a rear end of any age/mileage. They remove it just to change the fluid. You don't touch any moving parts whatsoever. Just get the correct oil, sealer, LS additive (if necessary), and go to town.

 

I too was going to put a new cover on my rear diff. However I also wanted to change the gears also... Any suggestions? How are the 4.10 gears workin' for you?

 

The 4.10s are excellent; a dramatic difference. It requires mechanical skills, experience, and a few specialized tools to do it correctly. If you're not familiar with the procedure, it's better to let someone do it.