Shouldn't it say what diff you have on the sticker under the hood?

 

Changing the gear fluid?? don't forget the friction modifier if its a LSD/sure grip !!!!

 

I try to follow the Owner's Manual in doing any kind of maintenance, but now I am stumped. The manual says that if the differential is a Chrysler, it came from the factory filled with SAE 80W-90, and if it is a Dana it came from the factory with SAE 90. Okay, then I should refill it with SAE 90. I can't find a parts store with plain old SAE 90. There is such a small difference between SAE 80W-90 and SAE 90 should I just go ahead and use the SAE 80W-90? Why did Dodge put 80W-90 in Chrysler differentials and plain 90 in the Danas? Is there a reason? There is nothing in the manual; regarding refilling the differential. If the service (usage) is normal, the differential is oil is not to be changed. If the service is severe, (Mostly towing) the differential oil is to be changed every 12,000 miles.

 

On changing the lub, what are the pro's and con's of sucking out the old lub? I have seen this done and sure seems easy.

 

Pros: sucking the lubricant out is easier and less time-consuming.

Cons: you don't get a chance to clean the crap off of the magnet, and you can't inspect the differential for signs of wear/broken parts like you can if you take off the cover.

 

I don't think that it matters, I used 75w-90 and I have zero problems.