trouble with new clutch

Fri Jan 04, 2013 2:52 pm

Hello all. I have a 1974 cub lo boy that I've owned since around 1990, great tractor. Any way while I was getting it ready for winter and greasing the throw out bearing I noticed a rather large gap between the clutch disc and the pressure plate. Adjusted as per the manual and found that the pressure plate that bolts on to the transmission was cracked. So being a little anal I bought an entire clutch rebuild kit, (hamilton bobs cub). Pull the old unit as per my shop manual and with some great advise that I read on this forum, and all went well. Installed the new unit but it seems that I cannot get this new clutch assembly to release cleanly. I have set the gap between the throw out bearing and the release fingers to .090 gap and the transmission brake pucks to .010. when I push in the clutch pedal and try to start the tractor the transmission brake are engaged and the clutch is not released, so it loads the engine starter down.I have moved the throw out bearing in closer to the release fingers and taken out the transmission brake and it starts OK but it seems that there is not enough movement in the throw out bearing to let the clutch disc spin freely. I really hate to get to long winded if you need more info or a pic I can do that also. Thanks bob

Re: trouble with new clutch

Fri Jan 04, 2013 3:18 pm

Welcome to the Forum!!
If you completely removed the brake pucks, you'll need to reinstall them. Without them there is just enough drag on the disc that it'll spin the plate, and along with it the top shaft of the transmission. This will cause the gears to grind.

Re: trouble with new clutch

Sat Jan 05, 2013 8:26 am

Thinking the problem may be in the pressure plate finger height and then readjusting the clutch pedal free play/clutch adjusting rod.

Re: trouble with new clutch

Sat Jan 05, 2013 10:59 am

Thanks for the replies. I have checked the finger height on the old clutch and the new clutch, the new one seems a very close when I measured. I have the shop manual which said it should be 1.210 " on the height. The new clutch and the old clutch do not seem to have any means of adjustment. the release finger just bolt to the pressure plate on the transmission. I was reading the owners manual and they were stating the distance between the throw out bearing and the release fingers is set to 3/32" and 1/4" wear in. I was setting it to .090" as per the shop manual. for the life of me when I watch the clutch work (stroke the clutch pedal by hand) I don't see how it releases the engine from the transmission. any way I was going to try and set the clearance to 3/32" and see if that works any better. Then if that goes south I may use the new pressure plate with the old disc and release fingers, they did not look worn very bad at all. Thanks again for the responces, and any ideas are greatly appreciated. Bob

Re: trouble with new clutch

Sat Jan 05, 2013 11:48 am

.090 and 3/32 are practically the same measurement.

The Operator's Manual has one additional measurement, 1/4" release. Check to see if the pressure plate fingers move inward 1/4" when the clutch pedal is depressed.

New clutch brake plugs?

Re: trouble with new clutch

Sat Jan 05, 2013 11:50 am

If the clutch is working correctly with the clutch brake removed, try reinstalling the clutch brake and adjusting it out until it does not press against the pressure plate. Then you can gradually adjust the brake back in until it stops the pressure plate from turning when the clutch is engaged.
If you have installed new brake pucks, the clutch brake setting needs to be adjusted quite a bit or it will be pressing against the pressure plate before the throw out bearing presses the fingers in far enough to make the clutch release. This is the way I always make the clutch brake adjustment after installing new brake pucks.

Re: trouble with new clutch

Mon Jan 07, 2013 10:18 am

When I replaced the pressure plate on my 184 (different design but same pressure plate) it took some use and re-adjusting before I got it to work properly. When newly installed, I couldn't get the clutch to release cleanly and still get the clearances to work out. I had to start the tractor (in gear) and work the clutch on a hill a bit. It took about 10 minutes of work to get it to release completely. (kept wanting to creep up the hill with clutch in).
It limbered up, but still didn't work well so I took it back to the shop and adjusted it again. This time all the clearances worked out.
Now it works perfectly.

Re: trouble with new clutch

Thu Jan 17, 2013 4:51 am

sorry it took a bit of time to get back but any way I've taken out and reinstalled the clutch 4 times now thinking I was doing something wrong. any way the last time I put the old pressure plate and friction disc back in (they were not in bad shape at all) and set the clearences and it worked perfectly. I have no explanation what is up with the new pressure plate. So until spring its going to be just fine, I was going to contact Hamilton Bob's Cub and see if he has any ideas about this. I can't thank you guys enough for your help and support. I know I have a few more projects coming up so I know I'll be intouch. thanks again Bob