NP200 transfer case rebuild problem

[asstor]

Hi guys.

I am doing a complete nuts and bolts restoration of an early 1951 M37. You can check out my progress at www.m37rebuild.com.

I have run in to a problem with the transfer case rebuild I can use some advise on. Upon stripping the xfer case I discovere that the input shaft from the transmission has pretty sever damage to the roller bearing journal. It has develeop a condition known (as I have learned) called brinelling. It is caused by excessive vibration on the bearing. As the bearing is locked by the HI/LOW dog clutch when the xfer case is in high range, the needle rollers eventually create long dimples in the bearing journal. Check out the picture below.



Getting a replacement shaft is near impossible. I eventually found a NOS shaft from one of the usuall suppliers. Unfortunately it is even in worse shape from sitting on the shelf for 60 years.




The question is, which one of the two do you recommend I use? Which is the better of the two evils?

I have though of a third possible solution. I have a lathe with a tool post grinder, so I can machine and re-grind the journal and then replace the needle bearing with a sold bronze bearing that I can machine to the correct clearances.

I know the journal can also be repaired by metal spraying and the re-grinding, but I believe that is not a good solution for needle bearings and the cost may be prohibitive.

Any thoughts?

Thanks to all.
Louis Barkhuizen

 

[Roller]

Do not use a bronze bushing to replace the rollers, it will not get enough lubrication and will wear out. I wouldn't use the brinneled shaft either. The NOS one is questionable depending how bad the corrosion is. If it were my truck I would look for another shaft. Have you tried Surplus City Jeep parts? They have that shaft listed under M37 parts.

Frank

 

[asstor]

Frank,

Thanks for your reply. I too am concerned with lubrication to the bronze bushing......I called Surplus City Jeep parts two weeks back. They did not have any in stock, but said that he would get back to me when they got on ein from a supplier. So far I have not heard back from them. I guess I will be calling again today.

I appreciate your feedback.

Louis

 

[gringeltaube]

I have one input shaft (NOS) and can bring it to the GA-Rally, if that helps.

PM me for details.


G.

 

[GUNNY 155]

I would go with the metalizing (spraying) and re-machine to spec. It is expensive but do you want to pull the case and redo it again? When I did mine I had some minor brinelling on my shaft and also could not locate one so I took a chance and used it over. Mine was caused by the parking brake drum nut not being tight. No problems thus far.

 

[asstor]

I would go with the metalizing (spraying) and re-machine to spec. It is expensive but do you want to pull the case and redo it again? When I did mine I had some minor brinelling on my shaft and also could not locate one so I took a chance and used it over. Mine was caused by the parking brake drum nut not being tight. No problems thus far.

GUNNY,

Thanks for your post. I called a company that does the metal spray. They do not recommend using the metal spray technique for roller or needle bearings. Th point pressure created by the needle bearings cause the sprayed on metal to delaminate.


I appreciate your feddback.

 

[GUNNY 155]

Thanks for the reply. What they say makes perfect sense. I have used the process before on hydraulic shafts and other parts that do not have to carry a direct load. That is good to know and I will file it in my Brain Housing Group for the future.

 

[73m819]

I would use the nos shaft, and a speedy sleave