Gear/Diff Lube Properties of ATF

[crinkles]

I've though about combined lubrication systems for auto transaxles and differentials on FWD cars a bit.

Does ATF have remotely similar gear lubricating properties than say a differential specific fluid?

Obviously the auto box has gears being lubricated, but can an ATF be an optimum fluid for the differential, where the two lube systems are combined?

THis also raises the question for multi vehicle/generic ATFs - if they have been recommended for say T-IV, does that imply it is suitable for the diff lube properties also where the diff fluid is shared?

 

[Shannow]

I haven't seen any ATF type lubes used for hypoid type applications...most combined auto/diffs are parallel shaft, and don't have the sliding component.

 

[mechtech2]

ATF has no or very little anti wear [AW] or extreme pressure [EP] properties.
It is just OK for modern transaxles.

Why can they use it? Because they VERY rarely have hypoid gears - they have helical gears with mush less demand.

Also ATF is not so hot for shifting - it is friction biased the wrong way.

 

[MolaKule]

Quote:
Obviously the auto box has gears being lubricated, but can an ATF be an optimum fluid for the differential, where the two lube systems are combined?



Not if the differential is a hypoid system.

If the differential is a simple ring-gear system with planetary gear carrier, it can be.

However, the Extreme Pressure additive system in run of the mill ATF's leaves much to be desired.

Check out Redline's 70W80 or Redline's PSF for systems which have transaxles.