1948 Allis Chalmers B

[Morris Ferree]

We have a 1948 Allis Chalmers "B" that we want to change the transmission/differential fluid. What fluid should we use as a replacement? Do all three drain plugs in the bottom of the housing need to be drained?
thanks
moe ferree

 

[Jeff Z.]

Yes. Drain all three. 20w non-detergent motor oil is what Allis list in their manuals and that is what we have used for 50 years without a single trasnmission or rearend related failure.
There are also new hydraulic/transmission oils on the market but there is not much reason to switch to them since the 20w does the job.
That's up to you.

 

[old]

As Jeff says or you can also use Hy-tran type of oil are something like that. I use the UFT in my Cs which use the same hyd etc as the B does