What SAE is best for rear transaxle.
Model T ? Technically the rear axle is not a "transaxle". Many early makes incorporated transmission and differential into one unit. Modern gear oils and their viscosity ratings are totally confusing to me. Vendors sell what they term 600W should be OK for a T. Others may explain the array of lubricants that are available.
Welcome to the forum! If by transaxle you mean a Ruckstell, 600W is too thick, here is what I use, available from the vendors:
140 gear oil has always been the recommended gear oil for a T rear end, or differential, in the summertime if you don't use 600W.
For a Ruckstell you need the lighter S.A.E. 90 gear oil.
I never thought about it before, but if a differential has a two speed set of gears inside it could be a transaxle!??
Thank you for all the assistance.
It is, a split diff is also called a transaxle, also a limited slip diff can be and are called a transaxle, based on the torque split they are designed for.
I did not know that Frank.
Also, back to the Ruckstell gear oil, 75/90 is a good year'round gear oil to use.