TC18 -- PTO Stops Under Load

[Riddler]

I hope to obtain a service manual soon, but in the meantime, I'm curious whether anyone has experience repairing the PTO on 10 year old (approximately) TC18 boomer. I was operating a small rototiller with it the other day and all of the sudden the PTO stopped turning the tiller. In lift position, the PTO shaft and tiller will turn slowly, but when the tiller is lowered, everything stops when the tines contact the ground. The problem isn't in the slip clutch of the PTO shaft because the whole shaft stops turning (along with the tiller). The problem appears to be inside the PTO drive unit.

What would cause the output spline of the PTO to stop turning under load, but still generate some spline rotation in the absence of load? I'm thinking that when PTO drive unit fails internally, the spline stops rotating altogether, even against little or no load. Thanks.

 

[jinman]

I'm thinking your clutch needs adjusting. Sometimes PTO shafts have a shearpin that will act like that, but if you are sure the tiller's clutch is okay, then you have to suspect the tractor clutch.

 

[Riddler]

Jim, thanks for the input. Correct me if I'm wrong, but if there was any problem with the tractor clutch, it would show up when driving the tractor. The tractor drives fine, and changes gears normally. As I mentioned, the tiller's clutch (i.e., the slip clutch in PTO drive shaft) seems to be operating properly too. The problem is confined to the PTO spline, which stops rotating when it meets any resistance.

I hate to contemplate it, but it seems that there may be a problem with the gears inside the transmission that engage the PTO spline. If not the gear itself, than perhaps the mechanism (e.g., thrust bearing) that causes the transmission and PTO spline gears to engage and disengage.

 

[JC-jetro]

Jim, thanks for the input. Correct me if I'm wrong, but if there was any problem with the tractor clutch, it would show up when driving the tractor. The tractor drives fine, and changes gears normally. As I mentioned, the tiller's clutch (i.e., the slip clutch in PTO drive shaft) seems to be operating properly too. The problem is confined to the PTO spline, which stops rotating when it meets any resistance.

I hate to contemplate it, but it seems that there may be a problem with the gears inside the transmission that engage the PTO spline. If not the gear itself, than perhaps the mechanism (e.g., thrust bearing) that causes the transmission and PTO spline gears to engage and disengage.

Riddler,

Along with jim said, let's just see what you have. Do you have live PTO or independent? Do you know if you have single clutch /transmission driven pto? how do you engage pto? is it hydraulic, purely mechanical or electromechanical? With the engineOFF and pto engaged can you by hand pressure rotate the pto? if so, thenboth CW and or CCW rotation?

JC,

CW: Clockwise
CCW. Counter clock wise

 

[jinman]

Jim, thanks for the input. Correct me if I'm wrong, but if there was any problem with the tractor clutch, it would show up when driving the tractor.

Sorry, I glanced at the clutch diagram and thought it might be a 2-stage clutch. I now see the TC18 has only a single stage clutch. Also, PTO engagement in the transmission seems to be completely mechanical and is not live. The HST model does have a live 540 PTO, but the manual transmission does not.

Is the PTO lever moving out of the engage position when the PTO spline quits turning? Is there a chance the lever is bent and the PTO is not fully engaging and then jumping out of engagement? If you are certain that the PTO is being fully engaged and that the spline stub has stopped rotating, then I think there must be some internal damage to the PTO geartrain. Do you have a mid-PTO? Does it work normally?

 

[Riddler]

Sorry, I glanced at the clutch diagram and thought it might be a 2-stage clutch. I now see the TC18 has only a single stage clutch. Also, PTO engagement in the transmission seems to be completely mechanical and is not live. The HST model does have a live 540 PTO, but the manual transmission does not.

Is the PTO lever moving out of the engage position when the PTO spline quits turning? Is there a chance the lever is bent and the PTO is not fully engaging and then jumping out of engagement? If you are certain that the PTO is being fully engaged and that the spline stub has stopped rotating, then I think there must be some internal damage to the PTO geartrain. Do you have a mid-PTO? Does it work normally?

Jim, you've got the right read now on how my TC18 works. No mid-PTO, no HST, just a single clutch that operates both the tractor transmission and a non-independent PTO. The clutch seems to be working fine.

I'm going to the check the linkages and controls (which are all mechanical) this weekend (I am not around the tractor during the week). Honestly, it was stupid of me not to check that right on the spot. Between a linkage/control problem and damaged gears, the smart money would be on the former. That said, if the linkages/controls all seem to be operating properly, then I agree, I have a rather serious problem.

 

[Soundguy]

also check for in/out or side to side play on the pto stub itself.

soundguy

 

[Jp2012]

Riddler did you ever figure out what happened with your tractor. Having similar issues with a newer ls which is basically new holland with different graphics. Was pto clutch pack or broken gear inside pto?