So many choices

[SCOTTY088]

I'm ready to change rear diff oil. I'm blown away by how many choices of synthetic gear oils out there. I need help in selecting the best bang for the buck. I have a 2014 3500 Cummins with the 3.42 anti spin diff. Is the friction modifier required? I like to hear all ideas by folks who have experience in this field.


Thanks, Scotty

 

[Killer223]

no modifier is needed, any of the offerings are just fine. i use supertech from walmart, and mine is in great shape after 240K.

 

[Cummins12V98]

VERY highly rated is the AMZ/OIL Severe Gear 75-90.

 

[Jim W]

VERY highly rated is the AMZ/OIL Severe Gear 75-90.

X2; on Amsoil this is what I use.

 

[Dieselnut59]

x3 on Amsoil. I use it in my axles and manual transmissions.

 

[DonFitzwater]

I use a mix of Mobil synthetic or Evinrude Ultra hpf pro outboard gear lube, whichever is cheaper at the time. Have had no problems to speak of other than the occasional leaking seal.

American axles don't use clutches for the anti spin diff hence the reason for not needing a friction modifier.

 

[gsbrockman]

I have used Valvoline 75W90 and Mobil 75W90.....just make sure it is full synthetic and GL5 rated.

 

[SCOTTY088]

Ordered 5 Qts. Amsoil 75-90 severe gear synthetic. This lube comes highly recommended. Thank You folks for all your awesome feedback. Scotty