I went out today to change the diff fluid on my truck since it's still the break-in fluid (with 9338 miles) and I figured changing it would be a good idea. I had bought 3 quarts of 75W-140, having remembered reading that it took 2.5 quarts or so. Turns out it takes more than that, because upon refilling it it took all 3 quarts, and then it was roughly 1/2" below the fill hole. At this point I'm debating whether or not I should buy another quart and fill it all the way up to the fill hole, my standard practice. Advice?

When I drained the fluid it definitely looked like it was break-in. Not dirty but I saw little shavings. Also, the drain plug (which appears to have a magnet on it) had picked up a lot of stuff.

Also had planned on changing the tranny fluid in the NV5600 (also break-in), but didn't realize the only way to drain it was from the PTO cover. Seeing as I don't have any silicone and don't feel like going out and getting any, I'll do it another day.

 

My 11.5 took 3.75 quarts - filled to the hole. The mud you saw was typical. I'd fill it to the hole; but these AAM's can start all kinds of "fill-to-the-hole" wars .....

You don't need any RTV to drain the tranny. If all you want to do is change the fluid without looking inside, just remove the bottom PTO bolt to drain the old stuff out. Just make darn sure you have the 17mm hex to remove the fill plug before you drain. I used about 4.7 quarts to fill the tranny.

 

Yep, I have the 17mm hex to remove the fill plug (tested it and it fits). I'll go out and change the tranny fluid in a bit then. I guess I still need to go back to Mopar and get another quart of fluid. I tend to err on the sie of more fluid is better than less. Thanks!

 

Mine took 4 and its just ever so little below the hole.

 

And mine took about 4.5 just now. It would be my bet that it varies depending on just what angle your truck is at when you change the fluid.

Thanks for the tip, bulabula. My faith is restored in NV's design intelligence. Now if only they had marked that hole "DRAIN" or something like that.

 

You may want to go and rethink the 75W-140. Per DC & AAM in DC's Owners manual the AAM uses 75W90 and requires NO equatorqe.

 

I remember reading either on this forum or on the TDR that Dodge has a TSB recommending 75w-140 for the 11.5" if you're towing.

MikeyB

 

Right again Mikey.

Mike.

 

After I just went out and got AMSOIL SEVERE GEAR 75W-90 ..ARG

 

tsb 03-001-04 rev. a ----- 11.5 rear, fill to within 1/4 in. of fill hole +or- i/4 in.
fluid cap. 122 oz. sae 75-140 synthetic. No mention of towing.

rob

 

i contacted d/c last week about which fluid to use in the 11.5 rear diff. they said to use 75w-90w!!

 

Does it say anything about cold climates with the 75W-140??

 

tdupuis, your welcome. As I think back, mine was probably more like 4.5 too; my 4.7 number included the stuff that soaked into my sweatshirt when the fill hose came out of the hole and slobbered up my shirt as I was laying under there pumping it in.

The good news is that I have yet another good looking oil stained sweatshirt to wear when changing the oil.

Next time I do the diff's, I'll be putting in 75W-140; but I don't lose any sleep because mine currently has the 75W-90 in it.

 

Dave65-----No mention about cold weather, the only other concern in the tsb is that some trucks had fill holes that were considerably higher than the actual fluid level hence the " fill to 1/4 in. below the fill hole+or- 1/4" The way i read this you can still fill til it runs out if you want

rob

 

Ok thanks Rob