Here's some good links:
http://dodgeram.org/tech/specs/axle/9_25specs.html
http://dodgeram.org/tech/specs/axle/axlespecs.html

They say the opposite of what I just stated eariler as far as front and rear, so I might have that mixed up. Truth is, the last few gear oil changes I have done, I just used 80w-90 in both.

 

I've done the opposite. I've put 75w90 in both. Either way you will be fine.

 

Alright nice, then I should be alright. I mean if it's supposed to be 80w-90 in the front, I am using 75w-90 so it should be cool. And then for the rear, I got the right stuff, so sweet. Pretty happy I did the front. The front oil looked rough, it was half brown/half green. I remember mechanics were quoting me $100 just for the front. I only spent $25 for oil for the front, can't complain. Now just have to wait for the parts to come in Tuesday, and then off to work we go. Very excited to get this truck rolling again, miss it. Also miss having a vehicle (not that it's important or anything[8D])

 

That Mobil 1 you got is what you want. I run 75w-90 in mine too only I run Royal Purple instead of Mobil 1. You want to fill it up until it runs out that fill plug thats in the middle of the cover. Most bottles you can just squirt into there.

 

The 2001 owners manual states that 75W-140 ca be used for extreme duty/towing situations. I've also heard of guys using thicker oils to mask a gear whine problem.

 

HTM, thats why i went 75w90 in both was because it was easier to get for royal purple. I got mine for about 8bux / bottle about six months ago now.

 

Wow where did you get that? I think I paid like $13 a bottle for me Royal Purple. I used to run it in the rear too but can't now so I ran Lucas. I think it was $5-6 a quart or something.

 

After letting the rtv set for about 4 hours, I went back outside to fill the front differential up with the mobil 1 synthetic oil. It was kind of tough trying to fit the bottle into the hole, but after a couple spills onto the driveway I was able to aim it down the hole. Took about 2.5 quarts before it started oozing out of the hole. By the time I was done filling it I pretty much wanted to throw up lol, really hate the smell of gear oil. I love the smell of motor oil, gear oil just aint my bag lol. Anyways, after it was filled up, I tightened the plug hole up. So now I had a lot of orange sticking out of the sides, so I knew what I wanted to do. I got my rubberized undercoating bottle out, and I resprayed the entire diff. cover. Not only does this cover up any of the orange gasket maker, but it will also act as a second gasket maker covering up the seals and drain hole so that's pretty cool. Then I went to the rear, and really got in there and cleaned up inside of there. Looks new now, and the magnet is very visible, so that's pretty cool. Now, just gotta wait for those damn parts...

 

A trick for future reference is take a razor blade and cut the excess off that gets smooshed out the sides of the cover. I'd be afraid the coating stuff would act like a glue and me not be able to get it off next time like I had a problem with the other day when I did mine. It should be fine though.

BTW what kind of stuff did you use that was orange? I use The Right Stuff and it's black. I've seen other guys use regular RTV but it's usually black too.

 

It was RTV, but it was high temperature. I just figured to go with the high temperature. I wasn't sure if running 35" tires would heat the oil up more than usual, so I just rolled with it. But it was pretty fun stuff to work with, and works really well. Excited I got the front differential dealt with. I really got that cover and housing super cleaned up, and then sealed it off really well. Next time I use the 4wd, I will be in heaven knowing that mobil 1 synthetic is swishing around in there because I'm weird like that[8D]