Don't know about ya'll's owner's manual, but my '04 manual says that if you tow heavy to change it at 30K. If you don't tow, there is now prescribed interval, i.e., you don't have to change it.

There is NO requirement for a limited slip additive with the AAM axles, at least that's what my owner's manual says. Use it if you want to waste some money. Won't hurt, won't help anything either.

I use Redline full synthetics in the truck axle, Harley trans and primary, T'bird transmission.

Isn't it misrepresentation to label a product as "synthetic" if, in fact, it's not? I would think the FTC would require some sort of caveat such as "Equivalent to" or "Performs as well as.." But, what do I know?

 

Nelrod,

All I know is that when Mobil 1 first came out they said their oil would last 25,000 miles or one year just like Amsoil did. Not sure if the suite is why they changed or not. All I know is that they dropped the 25,000 miles oil change back to 3,000 miles. It’s only been in the last year or so that they brought back oil that they say will last up to 15,000 miles.

I to think the Rotella is hydro cracked/super refined dino oil. I only know of two that I think are true synthetic and they are Redline and Amsoil. There could be more but I don’t keep up with it anymore.

Turk,

As for Royal Purple gear lube, I don’t know any thing about it and have not heard of any thing bad being said about it. As they say it’s your dime!

Tacook,

You said, “I don’t have a chatter, just a rear end whine when I'm on the gas.” If it keeps up or gets worse then get it in to be checked out. It’s cheaper to have a problem found early then when it’s to late. Be safe and not sorry. An ounce of prevention is worth a pound of cure.

Just my $0.02 right or wrong!

 

Royal purple is a very good full synthetic oil/fluid, as is amsoil and redline.

 

where can i buy the good fluids online? my walmart has generic brands..

 

There are several vendors on ebay that sell Redline. Last price I paid was $7.95 a quart.

 

You can always tell full group 4 syn.by the price.Group 3 so called syn.is always less exspensive.

 

I like Redline stuff. I have had good luck in the past. I have some 75W90NS I need to put in my diffs, I just haven't gotten around to it.

 

Same with an 2007, no additive???

 

Yes, same. AAM axles use a gear type Limited Slip differential. It's the clutch pack types that use additives.

 

I'm running redline 75/90 in my 06.....

So good so far.

 

I am running 75/90 Amsoil Severe duty with no problems. I thought any GL-5 rated synthetiic should work. And there should be no need for any limited slip additive, however, some guys running heavy weight gear oils have noted that once they added a limited slip additive, the clunking they were getting in the turns went away.

 

I ran Redline 75-140 in both axles in my last Dodge (03) at the dealer's suggestion. On this one, I just changed both to 75-90 front and 75-140 rear.

I e-mailed Redline and asked if I should order the NS (No limited slip additive) for the AAM since it doesn't require additive. The engineer replied back that with the clutchless system the 10.5 AAM uses no additive is required so I could use the 75-140NS, but that the limited slip additive they use in the regular 75-140 actually would reduce friction and oil temps in the gear contact area, and would not harm or adversly effect the AAM limited slip... so may as well go with it...

The rear axle has a "Fluid Line" stamped on the back cover that is significantly below the hole, and would be easy to not notice.