Replacing PTO forward cam.

D

Dan Stuckey

Well-known member
Well let me start out by saying that I have recently changed over from the original Farmall cub to a lowboy 154. So today while mowing I went to pull up on the PTO lever to disengage the blades and I ended up with a whole lever in my hand. Taking the back plate off behind the rear PTO pulley I found that a portion of the forward PTO cam had broken off and was still attached to the PTO lever. So I have a order in for the new Kim and was just wondering if this is much of a job to place this into the PTO assembly.

I know I might be in for a job getting the pulley off the end of the PTO but I will deal with that with a little heat. And does anyone know if there is a diagram of the PTO. I spoke with Bob at Hamilton Bob’s and he recommended looking at a exploded diagram and putting the PTO back correctly as so many of them that he looks at are not put together correctly on previous repairs. I appreciate any input on this
 
I just rebuilt my 185 PTO clutch today. Really not a bad job at all. Hardest part was getting the pulley off, which took a little Kroil, a prybar, block of wood and small hammer. Remove the PTO cover sheet metal.Three 1/2" bolts hold the PTO clutch bracket to the top of the rear end. Remove them and the 2 bolts that hold the linkage to the forward cam and slide the whole PTO clutch assembly out.
Once out, just remove the spiral clip and disassemble in order. Mine was put together correctly, but I'm sure Hamilton Bob's has seen them put together wrong. On mine, the forward and rearward cam bearings had locked up. Also the friction discs were worn. I replaced the cam bearings, friction discs, steels,wavy washers, rain band and handle spring. All parts were from Hamilton Bob's and were excellent quality, as everything has been that I have bought from them over the years.
Service manual from MTD:
http://manuals.mtdproducts.com/mtd/Publ ... doSearch=Y
 
FSJNut":2rhrls37 said:
I just rebuilt my 185 PTO clutch today. Really not a bad job at all. Hardest part was getting the pulley off, which took a little Kroil, a prybar, block of wood and small hammer. Remove the PTO cover sheet metal.Three 1/2" bolts hold the PTO clutch bracket to the top of the rear end. Remove them and the 2 bolts that hold the linkage to the forward cam and slide the whole PTO clutch assembly out.
Once out, just remove the spiral clip and disassemble in order. Mine was put together correctly, but I'm sure Hamilton Bob's has seen them put together wrong. On mine, the forward and rearward cam bearings had locked up. Also the friction discs were worn. I replaced the cam bearings, friction discs, steels,wavy washers, rain band and handle spring. All parts were from Hamilton Bob's and were excellent quality, as everything has been that I have bought from them over the years.
Service manual from MTD:
http://manuals.mtdproducts.com/mtd/Publ ... doSearch=Y
Click to expand...
.

Thanks for the great info. Waiting on parts from Hamilton Bobs. He was great for info and offered his brain help anytime. My pulley was impossible even with me torches, Kroil and blocks of wood. So told Bob to throw a pulley in the box with my other parts as I was getting some distortion on the old one. So broke out my grinder and cut off the old pulley.

So while waiting on parts, did a engine clutch adjustment today which was needed along with the brake clutch which was not even close to proper adjustment. Glad to be learning the different stuff that is different from my 49 Cub.
 
Wow, it sounds like your pulley was really on there!
Well, I'm waiting on parts also from HB. I got my PTO clutch together and all looked good, I thought. It lasted about 20 minutes. Wouldn't stay engaged, and was smoking. Totally my fault. Apparently, just guessing here, when the original rear cam plate bearing failed, it got the spring plates very hot and took the spring out of them. They were totally flat. I did not realize this when I put it together. When the plates are flat it allows the outer race of the rear bearing to rub, creating massive amounts of heat. Turned the bearing and spring plates blue. I have ordered from HB new plates, bearings, snap rings, etc. Hopefully this second pass will get things working properly.
Hope things go better with your rebuild.
Even though this has been a bit frustrating, it is still a pleasure to work on things that were built heavy duty, and to have a great supplier of parts, Hamilton Bob's, to make repairs possible.
 
I find that the most important item is to check the lock vs. unlock distance. Must be 0.050" for clutch to work properly. This is covered in the technical manual. It can be adjusted by adding or removing shims.
 
FSJNut":30jlql6r said:
Wow, it sounds like your pulley was really on there!
Well, I'm waiting on parts also from HB. I got my PTO clutch together and all looked good, I thought. It lasted about 20 minutes. Wouldn't stay engaged, and was smoking. Totally my fault. Apparently, just guessing here, when the original rear cam plate bearing failed, it got the spring plates very hot and took the spring out of them. They were totally flat. I did not realize this when I put it together. When the plates are flat it allows the outer race of the rear bearing to rub, creating massive amounts of heat. Turned the bearing and spring plates blue. I have ordered from HB new plates, bearings, snap rings, etc. Hopefully this second pass will get things working properly.
Hope things go better with your rebuild.
Even though this has been a bit frustrating, it is still a pleasure to work on things that were built heavy duty, and to have a great supplier of parts, Hamilton Bob's, to make repairs possible.
Click to expand...

Sorry to hear of your problem but at least you figured out what caused the failure. Got mine all back together and checks out ok. I did have some scraping from the new cam plate flange against the clutch basket but all I had to do was bend the flange away from the basket.

Saw a bit of a problem with the clutch plate as I was checking things out. Seems the rivets are loosening up that holds the center hub to the clutch plate. Hoping it holds out til winter. Nice project then.
 
I received my parts from HB quickly but haven't had a chance to work on it until recently. I replaced the new cam bearings and spring plates. When I got it all put back together the PTO clutch wouldn't disengage. Couldn't get anywhere near the .050 you are supposed to have between engaged and disengaged. I ended up putting it back together with the old friction discs and it worked but would still slip under heavy load. So, I did the smart thing you did Dan and called Bob. He was super helpful. Told me that a thick washer that was installed right behind the spiral clip was not supposed to be there. Only the spiral clip and shims before the pressure plate. So when I out the clutch together with the new friction discs and no washer I could get the .050 with no shims and it would disengage perfectly.
I mowed with it today and the PTO worked great. Engages/disengaged perfectly and no slip in heavy grass.
I would do this again, especially now that I am familiar with it. Heck, I timed myself removing the PTO clutch. 8 minutes from first belt cover bolt to PTO clutch on the bench. Next time I would make sure the spring plates are still cupped and not flat as mine were.
 
Merpa1680":1lsn0eqm said:
How long does the whole process take? From disassemble to reassemble?
Click to expand...
It's been years since I reworked my 154's PTO clutch. No real answer. Just the PTO, maybe 2 hours, maybe less, if no problems are encountered.
 
You must log in or register to reply here.
Back
Top