Tearing up spline teeth on clutch disc

[37packard115c]

I'm not sure what happened here. My wife mowed the grass for a month while I was out of town a few years ago and she said the tractor started making a horrible sound when she pushed in the clutch. OK, I figure she was riding the clutch. I split the tractor and replaced the clutch pressure plate and disc. No more noises until 6 months later when it started happening to ME! Split the tractor again and replaced the disc. 3 weeks later it started happening again. Split the friggin' thing again and took a close look at what was going on. The spline teeth on the drive-shaft are tearing up the spline teeth on the disc. It has worn them down to little blunt points. I'm not sure how this could happen. Does anyone have any ideas?

 

[ETRon]

Best I can do is offer some generic advice back to ya. I guess this may be obvious but if you are tearing up the hub on the clutch disc then the splines on the tranny input shaft need to be inspected very closely as they're the most likely culprit. Unless the sides of the splines are smooth the disc will bind and tear itself up. Check it for damage. The area where the disc rides on the spline shaft may look a little smoother that outside of that area but grooves and burrs are a fail. I'll probably get trimmed for this but if the damage to the shaft is such that you can catch your fingernail on it the clutch isn't going to work right. Also you need to replace the pilot bushing or bearing in the center of the crankshaft (whichever it has) whenever you rebuild the clutch.

In all likelihood given how fast you say the disc is being torn up the input shaft is damaged pretty bad as well. Just my 2 cents without seeing it of course. I hope it isn't but.... Good luck, let us know what you find on re-inspection.

Ron

 

[fj40dave]

I'm with ETRon....something is amis in the mating surfaces.

 

[37packard115c]

Thanks guys, I think I've mowed for the last time this year, so back into the barn she goes for more surgery.