Rear Diff FLuid

[Jaceracer]

Hey guys is everyone using a 75w-140 diff fluid i see it calls for 75w-90

 

[P49Y-CY]

Hey guys is everyone using a 75w-140 diff fluid i see it calls for 75w-90

not sure if this directly applies to your lightning, but tsb #05-23-3 replaces the lube spec from 75w-90 to 75w-140 on 2002-2004 f-150's

 

[TXRickC]

Amsoil 75W-140 (x3 qt)
Amsoil Slip Lock.

 

[Jaceracer]

I bought a ford performance rear cover and ended up going 4qts of royal purple 75w-140, motorcraft friction modifier, even though that fluid says it has it in it. I also went with a lubelocker gasket. I just do not like using rtv anymore unless I have too.