Keeping Rear diff temps DOWN.....

[roperteacher]

OK, I had the rear end rebuilt at 2500 miles. Since then their has been some noise between 67-70MPH... ( As many of you have read)... . good news is, at 8,000 Miles the noise has pretty much GONE AWAY... . broke in or what have you. If the outside temp is less than 70, I never hear a darn thing. . if it gets to 90+ and I am towing. . I can hear some noise, but NOTHING like it used to!!! It's so much better. My questio is, the noise is temp related. When I go to change the rear diff fluid, what brands have actually been PROVEN to run the coolest in the rear diffs??? I have some Amsoil 7590 ready to go. . Heard Royal Purple is good too. . Right now the dealer has put in Synthetic 75-90 Just as AAM had mandated. I do tow a horse trailer on weekends. THanks`!

 

[Dean Upson]

I tow a heavy fiver and my temps have always been okay with the Mopar 75w90 full synthetic. I have checked them towing with an infra-red thermometer and the readings have been in the low 150's. Whatever you use, be sure that it is a FULL synthetic.



Dean

 

[roperteacher]

Yep, I knew about full synthetic! I think on the AMSOIL site they claim a 20 degree reduction in temps , but I think that is compared to regular oil, not another brand of 100% synthetic. Thanks!

 

[Eric_77]

I added the Mag Hytec cover and Amsoil to mine I never have checked temps with a guage but the MAg Hytec does add about 3 quarts to capacity. With the old hand touch the stock cover would be hot you can touch but not leave hand on for long with new cover and oil it is a bit cooler as I can leave my hand on it.

 

[y-knot]

I have the MagHytech cover also, the added oil capacity is great. I do monitor the rear temps with a inside mounted Gage, they are always in the 140-150 range, towing or not.

 

[ttreibel]

Add a Mag-HYTEC cover bring up your total capacity to about 10 quarts and also try 75w-140w Royal Purple Synthetic that should do you good

 

[Yo Hoot]

Go Mag-hytek. Worst case I know somebody that runs a pump driven off the driveshaft and through a cooler.