Is My PTO Clutch Worn Out?

[chesbaycruiser 82]

I have a 1975 B-80 that has recently been put back into commission. The other day, I started to use it to mow with for the first time, and when I engaged the pto, the deck came right to life, however as soon as the mower blades encountered any grass of substantial thickness, the PTO slowed down and in some cases, stopped all together.

The engine runs and pulls strong. I'm guessing the PTO clutch is worn. Does this sound right? Any other possiblities, or ways to confirm?

Assuming it's the clutch plate, I've perused the Toro site looking for a new one searching on my B-80 model number (1-0141). That returned parts for a B-100, including "94-6650- ASS'Y-CLUTCH PLATE" for $60.76.

I'm assuming the B-100 parts will fit the B-80? Anyone know of other sources for new parts? (Don't really want a used clutch plate!)

Any feedback will be appreciated.

Thanks,

Chris

[kpinnc 11,877]

Your clutch probably just needs adjusting. All of the PTOs have an adjustment to tighten the contact with the PTO bell, regardless of the type. I would also check the tension in the mule drive, if your tractor is equipped with one.

I've also had the PTO bearing sling grease out onto the friction disc. It will slip for a while until the grease is cleaned off.

Kevin

[Docwheelhorse 2,660]

Take the PTO clutch bell off and make sure you haven't worn the plate down to the rivets. You may not have rivets and that would be a pleasant surprise, smear a bit of grease into the roller bearing when you are putting it back together and then tighten the trunion on the PTO engagement rod a couple of turns. That should fix it and have you mowing in no time. The only clutch disks I have ever replaced where the ones that the rivets have been exposed and where being ground down. If you have an epoxied clutch face it will last forever.....

Tony

[Don1977 604]

The clutch disk I replaced throw the lining out in little pieces. It wasn't near the rivets until it exploded. :drool:

[Tony S 2]

I rebuilt the engine on my C-125 and replaced the clutch lining, and when I went to use it last week it slipped. I tried adjusting it to no avail, and then I remembered reading on here that if you put the crankshaft pulley on too close too the crankcase it affects the clutch operation. I moved the pulley away from the engine block so that the sleeve that the PTO pulley runs on protruded over the end of the crank by about 3/16" rather than the crank poking out through the end of the sleeve by 3/16". I then re-set the clutch adjustment and it never slipped at all. It was the first cut of the season and the grass was thick and clumpy and I cut a bit low but there was no stopping it, it really made the engine bark, awesome! :omg:

[hodge 6]

Also check the belt tension, and adjust it at the mule drive. If the belt tension isn't right, it will slip, causing the deck to slow down.

[WheelHorse_of_course 99]

See Q&A here:

http://www.wheelhorseforum.com/index.php?showtopic=3464

:omg:

[JoeMonag 1]

I recently rebuilt the PTO clutch, on my 1988 310-8 . I ordered through a local dealer over their internet site, and then pick up the parts. the clutch plate was 58.00,the oil seal was 4.18, the needle bearing was 19.72, and the ball bearingwas 13.09. I had to pay sales tax, and and some ups charges. Just after I bought all the new parts, I saw a bunch on E-Bay. I think I get another 20 years out of the rebuilt PTO, so I didn't mind paying for all new parts. Some have found the bearings for about 1/2 of what I paid, from bearning suppliers. I was surprised my dealer prices were better than the Toro site. I'm glad to have it repaired, as I use it to power my belt driven generator, which is my emergency back up power for my sump pump, and heat. The previous owner ( I bought the tractor in 2007) it appears ran a snow thrower and tiller. My clutch plate was down to the rivets, and the rollers fell out of the roller bearing when I took it apart. At the suggestion of my fellow wheel horse buddies I thoroughly greased and lube the assy. during the rebuild. I also replaced the brake pad assy.

good luck finding a good dealon the parts. Joe in Norton

[chesbaycruiser 82]

Thanks to everyone for all the great input! I had tried adjusted the mule drive and also the PTO trunion...with no appreciable change.

I've been sidetracked with family-related committments the last few days, but will try some of the other suggestions this week.

If no joy, then I guess I'll be shopping for the new hardware.

Thanks,

Chris

[WheelHorse_of_course 99]

Thanks to everyone for all the great input! I had tried adjusted the mule drive and also the PTO trunion...with no appreciable change.

I've been sidetracked with family-related committments the last few days, but will try some of the other suggestions this week.

If no joy, then I guess I'll be shopping for the new hardware.

Thanks,

Chris

Chris,

THis has probably been mentioned but I would confirm you deck doe snot have a problem that is increasing the load.

The easiest way to do that it to try turning the PTO bell by hand with the Engine off and the PTO disengaged.

Depending on the size of your deck it should be reasonably easy to turn by hand. Also turn several revolutions and see if the the effort required varies (if so that is a bad sign).

I'd like to throw something else into the equation - I Have noticed that the PTO brakes use brass rivets. I have also looked at brand new PTO brakes and there is NEVER more than 1/32 inch depth before the top of the rivet.

This leads me to believe that on the PTO brake wearing to the rivets is a normal condition and since the rivets are brass they do not damage the mating surface.

I wonder if this may be true of the PTO clutch (and I believe at once I have seen brass rivets) it is entirely possible that wear down to the rivets might not be a big deal.

That said, if the head of the rivets wear fully down you would have the exploding PTO phenomenon once that happens.

Anyway, best of luck getting this sorted out.

:drool:

[chesbaycruiser 82]

Hey All,

Thanks again for all the great input. I pulled the PTO apart and inspected the friction plate, which appeared to be OK...no rivets showing, and about 1/8" thickness.

After removing the the friction plate, I could see wear on the belt cover, which seemed to like it might support Tony's notion of the drive pulley being to close to the engine block.

I loosened the pulley and pulled it out about 1/8" to 3/16", tightened it, and put the whole thing back together. It ended up giving me a lot more adjustment with the trunion, which appears to have soved the problem. I did some quick testing in the yard and all worked well, athough my grass is not very tall right now. It was getting dark and starting to rain when I finished, so I'll test more when I have more time and taller grass, but I'm pretty sure I'm good to go.

I've attached a few photos of the work. (Note the Red Square reference materials.)

Thanks again,

Chris

---------------------------

PTO with the housing off

PTO Clutch Plate Thickness (with Quarter for reference)

Drive Shaft and Pulley showing belt guard wear

Using Red Square Input!!!

[Tony S 2]

Hi, your tractor looks really good. I wish I had a garage / workshop like yours. Hope all is O.K. with your PTO clutch now.

Regards

Tony S. :omg:

[chesbaycruiser 82]

Thanks Tony, for your great suggestion about the drive pulley, and for the kind words about the garage. Actually, you are looking across the tractor at the overly-clutterd (wife's) side of the garage!

OK...to be honest, some of the clutter is mine (note the 60's vintage Flexible Flyer in for repair). The garage does make working easier, especially after I installed a couple of sets of 8' flourescent tubes to brighten the place up!

Thanks again,

Chris

[hodge 6]

There's your problem- you had a quarter stuck in the clutch!

[chesbaycruiser 82]

:omg:

"Is that a quarter in your clutch, or are you just happy to see me?"

[Warning:Unsupervised 81]

What garage? Is there a garage in that beautiful Wheel Horse photo?

[TDF5G 2,069]

On 4/12/2009 at 4:32 PM, Tony S said:

I rebuilt the engine on my C-125 and replaced the clutch lining, and when I went to use it last week it slipped. I tried adjusting it to no avail, and then I remembered reading on here that if you put the crankshaft pulley on too close too the crankcase it affects the clutch operation. I moved the pulley away from the engine block so that the sleeve that the PTO pulley runs on protruded over the end of the crank by about 3/16" rather than the crank poking out through the end of the sleeve by 3/16". I then re-set the clutch adjustment and it never slipped at all. It was the first cut of the season and the grass was thick and clumpy and I cut a bit low but there was no stopping it, it really made the engine bark, awesome!

I had the same problem with my B-80.  Moving the drive pulley out from the engine block put me back in business.  I fought it for a few years before I figured it out.

[heysavoy 16]

On 4/12/2009 at 12:05 AM, kpinnc said:

Your clutch probably just needs adjusting. All of the PTOs have an adjustment to tighten the contact with the PTO bell, regardless of the type. I would also check the tension in the mule drive, if your tractor is equipped with one.

 

I've also had the PTO bearing sling grease out onto the friction disc. It will slip for a while until the grease is cleaned off.

 

Kevin

 

I am having the same problem as Chesbaycruiser.  Can you tell me how to adjust the PTO? Mine is a 1990 and the tractor model # is 31-12KE01