Trans & Diff Fluid

lgt · Post by **lgt** » Mon Jul 18, 2011 5:29 am

1955 M38A1 Changing the fluid in the transmission & differentials, What type of gear lube is required in the trans & diff ?

thanks
Larry

major519 · Post by **major519** » Mon Jul 18, 2011 8:17 am

I believe hypoid gear oil. 80w90.

Post by **wesk** » Mon Jul 18, 2011 9:02 am

Go back and review the earlier discussions on this topic. Hypoid rated gear oil is designed for the differentials and it's qualities are not needed in the tranny and transfer. Regular gear oil is fine in them. In very cold climates 50 weight engine oil is fine in them. Old # 2 and 3 hypoid gear oils were low in sulphur and had no ill effects on tranny brass synchro rings. The new stuff went high sulphur which creates several problems. You can risk it and go with a new type who's marketing folks say it is ok with your tranny brass parts or be safe and use a regular gear oil in the 50 to 70 weight range. Many farm and industrial tractor supply houses can fix you up with quality plain gear oil.

http://www.willysmjeeps.com/v2/modules. ... pic&t=5366

lgt · Post by **lgt** » Mon Jul 18, 2011 4:10 pm

Thanks for all the great info.