1943 Farmall Model M right rear axle housing leak

[Kartracer91x]

Good morning Farmall Community, I was hoping to get some assistance on fixing a leak on my newly acquired 1943 Farmall Model M.

It is leaking from the right lower front of the axle housing where it bolts to the differential housing. After researching this for awhile this doesn’t seem to be uncommon with these tractors.

I saw one video where a gentleman was able to separate the housing enough from the diff housing to get black rtv sealant in, but did not know if the was the norm or not.

Anyone that could help with a video reference, or a detailed step by step would greatly be appreciated.

It is apparent that the gear oil has lots of moisture in it given the color, and I want to change it ASAP, but would like to repair the leak along with changing out the 13 gallons of gear oil.

Tools and mechanical knowledge not a problem, been building hotrods for 35 years, but very little tractor know how.

Also should I use 80W-90 or 85W-140 gear oil in it? Tractor Supply carries both.

Sorry i’m long winded. Any help is greatly appreciated.

[Mike H]

first of all welcome to the fourm
I have the same problem on the other side of my M [leak]
I took a little time and looked at the repair manual
Io me it looks like the hole in the side of the case is too small to do a total removal of the axle and bull gear.
you might have 1/2'' of room to move the axle housing off the case.
if you do make sure that the axle is suported so it does not drop down and break teeth off the bull gear.
hope this help

[Kartracer91x]

Mike H....thank you, I think I will give that a try. I’ll report back after I work on it and let you know how I faired.