I have a 2WD so less maintenance but I did the axle at 18k miles and it looked a little dirty. I put in synthetic mobil1 and when I did it again at 36k, it was like new. I also do some towing, not regularly but I take a yearly 2 week road trip with my trailer. I agree with the rest, it's good to do it regularly. At least get the original stuff out of there, especially if you have the LSD. Lots of crud in the rear axle from the LSD breaking in. I also have done the trans fluid exchanged out. Like Mikey said, a couple of beers and $100 and you get some peace of mind. Just keep the receipts.

 

If you spend $100 for the fluids you have $300 for beer. ;-)

I do some towing not that often right now. I mostly drive highway, so it wasn't to bad... I just like the piece of mind doing it myself. I'm moving to FL in 35 days and towing the boat A LOT more down there! :-)

 

Thanks for all the replies. I will have a look at the diffs, and see if a buddy of mine wants to make some extra cash. Appreciate the points of view.
Cheers

 

Hey guys, I don't meant to jack the thread, but I have some related questions. I'm in the process of changing diff fluids as well. I've read we need 75W-90 in the front and 75W-140 in the rear, but I went to NAPA and they looked it up for me and they said 90 in the front and rear. I'm not sure if makes that much of a difference, but I wanted to bring it up to some smarter guys than me. Also, I've read that the 3.55 gears don't have limited slip, but again, the guy at NAPA said I needed the oil with the additive. What gives? Anyone have any insight? Any mechanics out there that can verify what the books say? I tried calling the dealership, but they're closed sundays and tomorrow for memorial day and I'd like to get this done this weekend. Thanks in advance.

 

The RAM 1500 4x4 owners manual specifies 75w-90 in the front axle and 75w-140 in the rear. Limited slip rear axle requires additive. The 3.92 is limited slip. The 3.55 and 3.21 are not. I'm not sure about the 4.10, but that's only 4x2 so it doesn't matter to you. Listen to the owners manual, not Napa.

Rob

 

Yeah don't listen to napa for sure, they just read what the computer says and obviously it's not right. What bigblueedge said is right.

 

Rob hot it right on the $$! Follow the manual. If you have 3.55's you will not need the additive, since you have an open differential. Make sure you put 75-140 in your *** end and 75-90 up front

 

Ok that's what I figured, but if I buy the stuff with the additive, it's not going to hurt anything will it? Only stuff I can find around here that doesn't have the additive in it already is some cheapo brand.

 

Won't hurt it if the oil has the additive in it. I put in valvoline syn-power and it has the additive for the lsd diffs in it already.

 

Yeah that's what I bought. I'll just have to take back some of the 90 and exchange it for the 140. Thanks for all the help.