[ndfarmer]

Im changing fluids on my 670 challenger and the manual shows the rear rotor gearbox needing 85w-90. Talked to my local oil supplier and he hasnt heard of this type. Recommended just using 75-90. Is this fine or should I order some 85-90? Thanks.

 

[SWFarmService]

75-90 will be just fine, any type of oil rated for gear lube will be fine. I actually run hydraulic oil where I use to run 75-90 for better lube in cold weather and I have great results in fuel efficiency with it

 

[birchcreekfarms]

^ yup the 75w90 will actually be better if you have to run it when its cold out, a bit easier on startup.

 

[ndfarmer]

Ok thanks guys. I run 75-90 in all my gearboxes that require 80-90. The 85 just threw me off.

 

[Bubbaracing]

Supplier never heard of 85w-90?! It's very common. Even my local Napa has it on hand in 5 gal buckets. I believe the difference between the 75 and 85 is that the 75 is either synthetic or semi-synthetic.