A "Real" Spline failure

[James Clark]

That'll work and is much simpler.

 

A doweled tooling plate that can be moved from the gearbox to the clutch housing would seem a little more useful to me.

 

 

How could the idea be adapted to check the alignment of the clutch plate splines to the crankshaft?

 

It doesn't matter if the splines are aligned with the crank. The transmission shaft has to spin concentric with the crank. If the shafts are concentric, the splines will find their way to a condition of maximum contact - even if the plate is wobbling.

 

If the shafts are not concentric, the crankshaft will be constantly trying to pull the plate to one side. This will cause the male and female splines to start grinding each other to dust as the power is transfered across one or two splines at a time.

[JerryMather]

BTW, did you see the pictures of the other spline failure in the Oilhead forum. Same wear pattern on the trans input shaft (concentrated towards the rear), just a little worse than mine. You can also see plenty of lube still on the clutch splines.

When I did a spline lube on my RT years ago with 70,000 miles on it. The trans spline had the same wear pattern as yours but worse. We just lubed it and put it back together. It was fine for another 25,000 miles.

On the other hand, when I removed the trans on my KRS the other day, the spline looked as new as the day it was made, but it only has 27,000 total miles on it.

Looking at your photos it's clear that there was alot of heat added to that trans spline while it was grinding down your clutch. It shouldn't be that dark color that it is, but I think you may already know that.

At the time of my first spline lube, I just thought that the wear was normal for the miles that were on it.

[nrp]

I completely agree. On the other hand I don't see how a small mandrel (because of its associated deflection) will quantify the alignment error and the direction of the error very easily. Isn't there some way to read a small dial indicator mounted to the flywheel & indicated onto a reference surface in the transmission? I'm not familiar with the construction of the transmission housing, but this would seem easier and more accurate.