TC45 Clutch slipping

[Philfarmer]

I have a TC45 12X12 4WD with only 260 hours that I bought new 4 years ago that will hardly pull itself. I got it back to the garage in the lowest gear. The clutch linkage is adjusted per manual and feels ok. The dealer cost is $1450 to break tractor apart since warranty is out and after reading repair manual I understand why. Is their any way of checking for clutch problem without disasembly of tractor or has any one else had this problem? I have seen some problems on line with clutches sticking on NH compact tractors from rust which tells me moisture must be able to get inside housing. Could the problem be a wet disc? It is kept garaged but I do wash tractor. I have never had a clutch problem with other tractors I have owned and was surprised it was slipping with so few hours. The problem started while I was using the loader.

 

[jinman]

Phil, your problem is most likely not water on the clutch plate. If it were water, the heat would boil it off very rapidly and you'd be back to normal.

It might be oil, but I'd think you would smell it burning also. Can you smell the clutch getting hot? Did it happen all at once without any additional noise? Did it start slipping and just get worse?

I know that thrust bearings (throwout bearings) can stick or bind, but it sounds like you had a mechanical failure of the pressure plate. Since you say you can adjust the clutch, I'm guessing that it will adjust until the linkage is loose and then you can tighten it until the pedal starts to feel resistance.

One other thing...does your PTO work? If it slips too, then it pretty much has to be the clutch. If not, it is definitely not the clutch. Just a thought...

 

[RickB]

If you have measurable freeplay at the pedal and a slipping clutch disc, there is nothing left to do except split it and hopefully swap out the disc only. Is the $1450 labor only, or parts and labor? Pickup and delivery? Loader R&R? If a disc and pressure plate assembly is included in the quote, that is over $400 whereas the disc alone is under $200. If the pressure plate doesn't show much heat damage, I'd think long & hard before I replaced it with those low hours. An organic clutch disc shouldn't do much damage to the flywheel or PP friction surfaces.

 

[Philfarmer]

Thanks Jim. It started slipping all at once without additional noise but similar problem happened at about 150 hours and adjusting clutch fixed it. The PTO seems to work ok but I don't have it under load right now. I haven't smelled oil burning. You are right about clutch adjusting feel. I am not sure what else could be wrong if PTO works. The trouble shooting manual says spring problem if clutch slips. Is the spring the only thing that keeps plate against flywheel?
Phil

 

[jinman]

Phil, the spring pressure of the pressure plate is the only thing that holds the clutch plate disc against the flywheel. When you step on the clutch, the throw-out bearing pushes on the release fingers and this releases the pressure. The throwout bearing is mounted on a collar that goes around the transmission's pilot shaft (input). That collar slides back and forth because of a fork assembly that is attached to the pedal. That assembly has a small spring to help with retracting and keeping the throwout bearing from touching the pressure plate fingers when released. If any of these things are failing, it will require a teardown (breaking apart) of the tractor. I think you'll just have to "bite the bullet" on this one. It's sad and unusual for a clutch to go at so low hours, but it seems like that is the case with your tractor.

I suspect you will find the PTO will slip when you put it under load. Your clutch is a single stage clutch and the PTO is driven by the main input shaft of the transmission. It has it's own separate hydraulic clutch and brake that is actuated by the handle on the operator's platform. If the transmission isn't getting full power from the clutch, then the PTO cannot get full power either.

I'm sorry to have to say it, but it seems splitting your tractor is the only option.

 

[RickB]

Jim, the PTO drive is independent of the transmission clutch. Either by a splined hub bolted to the crankshaft flange or a splined hub attached to the pressure plate cover.

 

[jinman]

Thanks for correcting me Rick. I thought it was driven by the pilot shaft the same as the transmission. If it is driven independently of the clutch, then it will probably work normally. I must have misread the diagrams I looked at this morning...entirely possible considering I was half-awake.

 

[Philfarmer]

Thanks for information Jim and Rick. I didn't go into much detail about price to repair from dealer except I would remove loader and deliver tractor. I was hoping I was missing something simple that was wrong after reading repair manual like an inspection plate to remove, a way to dry out clutch if wet or something like the differential control causing the problem instead of clutch. Looks like I need to split tractor. Thanks again.
Phil

 

[jinman]

Jim, the PTO drive is independent of the transmission clutch. Either by a splined hub bolted to the crankshaft flange or a splined hub attached to the pressure plate cover.

Rick, with the knowledge of your correction, I re-looked at the diagrems this morning. Of course, you are correct. The PTO drive shaft is a concentric shaft that fits into the transmission pilot shaft. It is driven off of a damper that is sandwiched in between the clutch and the flywheel. The shaft turns inside the transmission input shaft and is completely independent of the clutch and 12x12 transmission.

For the HST transmission, this is mechanized differently. The pto damper drives the input to the HST transmission through the pump shaft which also goes through the transmission to the PTO clutch/brake assembly.