M936 Transfer case concerns/questions

[ClintA]

When using the M936 the other day the T case got hot where the short drive line come in from the transmission and started smoking. The truck did not want to move so I let it cool down and checked the oil level (Oil was good and has been changed not long ago) after letting cool down all was good and finished the job. Then yesterday driving it in low up a ruff road it got hot again.
Question 1 is could there be a bearing inside the T case going out?
Question 2 will a T case off any M939 series truck work on a M936 or are they a beast of there own?

I am worried that it is on its last leg but it might be an easy fix just the same, I hope someone can shine some light if they have ever had or heard of this happening. Thanks in advance and have a great day, Clint

 

[M35A2-AZ]

I have not seen your problem, but to answer your questions. I would say it is on its way out for sure.
#1 Yes there is bearings that maybe going bad.
#2 Yes the transfer cases are the same, you would have to move the PTO from the old one to the new transfer case.

Castle Bravo here in AZ has one for sale.

 

[Swamp Donkey]

The T-case has an oil pump mounted on the back to pump oil to the top. If this goes out or the pickup becomes clogged, the top end won't receive enough oil. Or it could be a bad bearing, but I'd suspect the pump first. Even a bearing with excessive play won't usually smoke until near destruction, if it's still properly lubricated. The pump is external and can be removed without pulling the T-case.

All the T-cases are the same. Anything different will be a bolt-on part and won't come with a new case.
Item #2 is the rubber packing and is the most common mode of pump failure. If this fails, it won't pump.

 

[simp5782]

It is more than likely the pump. Take the rear hose off and blow thru it and make sure it is not trying to collapse. This is the result of a bad pump. It did a little more than smoke.

 

[ClintA]

Update,
After taking it all apart I confirmed that the bearing failed big time behind the yoke. The T case could be saved I think? But I am not sure it would be worth it or I would trust it afterwords. I think I will just baby it home if possible and look into putting a new one under it. Is there any tricks in removing and installing that anyone knows about that will help me? ( remind you its under a M936). Thanks to everyone, Clint

 

[simp5782]

Out the bottom. No different if it was a 934 or you cant pull the bed on any other truck. Should take about an hour to have it all out. You can try replacing the bearing and flushing the transfer case out and back flush the pump hose on the back and try it. Doesn't hurt. What's it gonna do? Burn up? If you gotta rebuild it might as well rebuild it all.

 

[Swamp Donkey]

You should still check the pump. If the pump isn't working, you'll toast that new bearing in short order. It's even more critical for the pump to be working on a wrecker since you're pretty much always carrying a full load.

 

[M35A2-AZ]

My M936 has a little hatch cut in the bed above the transfer case, I guess it is for lifting the transfer case from the top then letting it down to the floor. On my M936 it is under the spare tire.