2005 Dodge Ram 2500 Silver Oil in Differential

[robd]

I need an opinion on what could be causing this. I changed the factory fill out at 26,000 miles when the differential started hopping around corners, (oil looked like silver paint)does not have clutches (the AAM 10.5" uses helical gears). Used what manual reccomended (syn 75w90 Mobil1) and was fine until I took our camper out last weekend. Once again it started hopping and I just changed again. This time the oil also looked like silver paint (40,000 mi). The gears look ok but this has me concerned. Does anyone have any info on these axles or what may be causing this.

 

[YZF_Eric]

Yikes. Silver, almost looks like liquid graphite?

 

[robd]

Yep, looks like silver graphite.

 

[deeter16317]

Regardless of what you've been told, the AAM11.50 does have clutches...they are termed "shoes" or "brake shoes" in the IPL. While they use helical gears to apply them, they still use clutches. The hopping you experienced was probably LSD chatter (clutch chatter) or a failing LSD unit. According to the FSM, when the AAM11.50 LSD (called a Trac-Rite) fails, it locks both axle shafts together...although I have read about other failures where they just quit working altogether. Either way, you should not have that much suspended metal in your differential fluid.

I would say you have failing LSD unit, which is not all that common, but also not unheard of either. The upgrade is a Detroit True-Trac from what I have seen lately.

Good luck.

 

[robd]

Thanks deeter16317. I will be calling dealer because it is still under the 7/70 warranty for the powertrain.

 

[mechtech2]

Helical or Hypoid?

Anyway, something is WAY wrong!

 

[deeter16317]

Originally Posted By: mechtech2
Helical or Hypoid?

Anyway, something is WAY wrong!




The Trac-Rite works similar to a helical LSD.

 

[deeter16317]

Originally Posted By: robd
Thanks deeter16317. I will be calling dealer because it is still under the 7/70 warranty for the powertrain.



I have 250k on mine...they seem durable enough, so don't feel it was anything you did/didn't do. I'm not the easiest on mine being its a 6spd and I have been at probably 450RWHP for the last 80k miles.

 

[robd]

Ok, I got the truck back from the dealer and they gave me the old "there is nothing wrong with it". I even took in a sample of the old oil in a bottle and they just said "yea ok" and really were not interested. I wish I would have left the old silver oil in the truck but they charged me $53.00 just to look at it. I guess I will be driving it until it does it again and then take it in with the bad oil.

Also two other things. The Mobil1 75w90 looks really thin to my uncalibrated eye. Is the Syn too thin and maybe should I be using an oil without a friction modifier (the Mobil1 has a friction modifier in its formula). The manual states the AAM axle does not need a friction modifier (maybe the clutches are slipping and wearing too much).

 

[oliver88]

I use Swepco 201 in mine...great gear lube and no LSD chatter.