What is the best way to change the differential oil in the rear? what type of oil is best? and would it be the same way in the front

 

Best way is to remove the diff cover and clean out all the insides of the diff oil by finger ect. Then just clean up the gasket material then bolt it together and fill it up.

 

ok sounds easy enough, i think im gonna have to use a lot of pb blaster because of how much salt is used on the roads in ohio, What is the best type of oil to refill it with?

 

Bolts shouldn't be too hard to get out they're enclosed and usually sealed in RTV.

75w-90 or 85w-140 will work.

 

I just did my Diff the other week.
I used the stock 80-90w that mopar suggests. MAKE SURE you get the additive if you have the Limited slip diff!!!!! (Its just called Limited Slip diff additive or something) I didn't get that by mistake and my truck was absolutely terrifying within a few days. The diff was clunking around a ridiculous amount in corners. A quick stop to my dealership helped me fix that since they pinged it right away when they asked about recent work I did to the truck.

 

Or switch to a synthetic oil, then you don't have to use a friction modifier.

 

should i clean off the old RTV and replace it with a new layer, my gues would be yes. what is the best way to get it all off? in this case would it be alright to use sandpaper to clean the surface since a new layer of RTV will be applaied or does it come off with just usin my fingers

 

I always try to get as much off as possible with just my fingers and nails then sand it down a bit to clean off all the lil bits or uneven spots.