1960 T-10 rebuild - main shaft question

[Joe P.]

Re: 1960 T-10 rebuild - main shaft question

THanks guys for the added comments.. Here is was a well respected T-10 expert advises...

"No that is not good ,may cause noise in 1st/2nd and 3rd gears, It will still work ,but remember that is the inner race of the needle rollers . does the third gear have in internal bronze bushing ? . There are Company's that can repair that ,either by hard welding or by pressing a hardened bushing on and regrinding it to size . If your 3rd has an internal bushing I may have a new or used one available . Larry"

[Joe L.]

Re: 1960 T-10 rebuild - main shaft question

THanks guys for the added comments.. Here is was a well respected T-10 expert advises...

"No that is not good ,may cause noise in 1st/2nd and 3rd gears, It will still work ,but remember that is the inner race of the needle rollers . does the third gear have in internal bronze bushing ? . There are Company's that can repair that ,either by hard welding or by pressing a hardened bushing on and regrinding it to size . If your 3rd has an internal bushing I may have a new or used one available . Larry"

Joe------


I'll repeat something I said earlier: the important thing here is that the OD of the shaft is within spec for its entire length. If it is, I do not see how the "pitting" will be a problem. The bearings or bushing will ride on the non-pitted surface and if that surface is within diametrical spec I cannot see why there would be a problem. Also, if it's within diametrical spec the case hardening should not be worn through.

If the surface is not within diametrical spec, I like the idea that's been mentioned to turn it down in a lathe and press fit a hardened sleeve of the correct OD.

[Joe P.]

Re: 1960 T-10 rebuild - main shaft question

Joe, i did check the spec. The nominal size of a new mainshaft is .763"/ .7635" , I measured my shaft at .7630".

[Joseph L.]

Re: 1960 T-10 rebuild - main shaft question

There is a metallurgical condition called spalling. That surface appears similar to the spalling on other bearing and wear surfaces I have seen. If this condition is not something that is not usually seen on this component, it may be the result of another issue that is causing the high loading between these bearing surfaces. What does the other load surface in contact with the needle bearings look like?

[Domenic T.]

Re: 1960 T-10 rebuild - main shaft question

The Borg T-10 bearing surface was a fraction of the Munci. It was always prone to failure because of size. A bushing or ball bearing would have done a better job.
Not saying it is bad, but the T-10, but it WILL do good with normal use.

Dom

[Richard G.]

Re: 1960 T-10 rebuild - main shaft question

Joe;
It's not spalling.
I agree "condition is not something that is not usually seen on this component."
I worked in reliability services for decades and we did root cause analysis, on bearings, all the time.
This doesn't match what spalling looks like. I speculated it may have been caused by particle denting? It could be many other things also.
I would need to look at it with some magnification and it would help if the matching bearing/rollers were also available to look at to come closer to identifying the issue.
Because their are so many T-10's that run 100's of thousands of miles without issues I would replace/repair and move on.
Rick

[Timothy B.]

Re: 1960 T-10 rebuild - main shaft question

Joe, on other thing I wanted to share with you given this type of damage is to have someone check the cluster gear hole in the front of the transmission to make sure it's not oval causing the cluster shaft to load the main shaft and roller bearing.

[Joe P.]

[Wayne L.]

Re: 1960 T-10 rebuild - main shaft question

I have had several main shafts repaired at the front tip. A good machine shop can turn down the damaged part and then press on a hardened sleeve.
FWIW, Wayne