Strange happenings in PTO-land

[dsholler 54]

Just did the first ever regular service on my WH 414-8. (did this when I got it, but this was the first time after use).. Cleaned the mower deck, sharpened the blades, greased everything, changed the oil, clean the air filter, painted the deck with the used oil etc. )

Put the deck back on this afternoon. Went to mow the lawn. When I engaged the PTO it worked fine, and cut for about 20 feet.. then it just stopped.. meaning the PTO pulley just stopped turning. I had not adjusted anything in that area, other than to get the mower belt on and off.

Turns out the clutch was not pushing it against the driven disk. I had to adjust the little doohickey (whatever that thing on the threads of the rod is called) nearly an inch to get it to lock against the disk. I have not started it yet, because it is pouring rain and the kids are asleep, so I do not want to fire her up in the garage (under the house) so I do not know if this actually works, but at least when the PTO is engaged now and I turn the pulley I can feel myself turning the engine.

The thing that is strange is that it has never shown any sign of slipping before.. and that it worked fine for those first 20 feet. I did check and the mower is spinning freely, I can turn it when the belt is on the pulley with one hand. It also did not make any noise (although I did have the earmuffs on) there was no squealing or anything like that, and while I have been running the belt to the outer pulley.. it does not appear to have frayed edges or be any cause of the problem.

Any ideas?

I realize it is probably not much help asking the question without having started it and seeing if it still slips with the adjustment.. but could it really have gotten that far out in that amount of time without something else being wrong?

[nylyon-(Admin) 7,232]

Maybe the snapping came off the doohickey center shaft?

[bk-scouter 93]

Adjusting the threaded PTO engagement rod should help in your problem. BTW., you should be running the belt on the inner/larger groove (closest to engine) on the PTO pulley so the deck blades can operate at the proper higher RPM's. Good luck.

-BK

[dsholler 54]

nylyon, I assume you mean a snap ring.. is that what holds the disk to the shaft? so the whole disk could have moved?

[nylyon-(Admin) 7,232]

On the outside of the shaft there is a snap-ring. It keeps the shaft from moving in too much. I have had one come off before, so it's something to check. (this is where TT's supposed to come in with a diagram)

[dsholler 54]

So if it is the snap-ring, then it will work for a bit wiht the adjustment until I go over a bump the wrong way and it moves again, yes?

[dsholler 54]

It does not seem to matter. I did not tighten it all the way to the end of the threads, but I tried several times, and each time it seemed to work for a few seconds, adn then started slipping.

Does anyone know if there is a good diagram (other than the standard parts diagram) of how to take the PTO apart?

Dan

[Duff 206]

This may be the "parts diagram" you've already found, but I've used it to figure out how things go together on my PTO's with some success:

Duff

http://www.partstree.com/parts/?lc=toro_consumer&mn=71-12K801%2C+C-120+8-Speed+Tractor%2C+1977&dn=803699-36990067-00022

[dsholler 54]

Thanks Duff, that is the one I have... I guess I will just need to get out the reading glasses and go to it..

[dsholler 54]

OK, now I am really baffled.

The snap ring was still in place, but somehow had gotten pushed out of the groove in the PTO shaft. It was looking a bit old and loose, so I got a new one and put it on there. I also cleaned some crud out of the groove (with a screwdriver, I did not take the rod out).

I then changed the PTO brake (mine was worn completely) and readjusted the PTO setting so that it was on the first thread where I could manually turn the engine when I turned the pulley (loosest possible). I made the brake gap from there, thinking that it would only need to go tighter. I then tried it out.. on that setting, clearly it was too loose, and was slipping from the get-go. I tightened it one thread, and did it again, and this is where I had the same problem as before..

when I engage the PTO, it spins up to full speed, but something about the spinning causes the snap ring to get pushed out of the groove on the shaft and slid toward the outside, allowing the shaft to drift in and the clutch to disengage..

I tried tightening the adjustment further (*more threads) but clearly that just created more pressure on the snap ring.

Is there something else for me to try? Do I need a new shaft? Anyone seen this before?

[312Hydro 474]

You can take the pto off and check the bearing. It may just need greased but I would check it .It could be starting to seize up and that might be what pushes the snap ring off. That groove,Is it square shouldered? Maybe it's rounded over on the outside shoulder? Just a guess.

[oldredrider 2,548]

The snap ring groove on the stub shaft is worn out. Get a new stub shaft and snap rings and all will be good.

[TT-(Moderator) 1,131]

(this is where TT's supposed to come in with a diagram)

Sorry..... my busiest time of the year & not in internet-land much.

@dsholler: In addition to checking the outer bearing, I'd be looking at the condition of the groove in the stub shaft. It has to have a sharp, square shoulder to adequately hold the snap ring. The snap ring also has to be the correct strength/thickness. (not a "Chiwanese cheapie")

[dsholler 54]

Well, the new snap ring I bought appears to be thicker and stiffer than the one that has been on there all this, time, so either the groove is worn out or the bearing is going.. so will check them both..

At the risk of displaying my profound ignorance of things mechanical, I have never replaced a bearing before it was really ready to go (i.e. squealing).. I assume I just need to clean it, grease it, and make sure it rolls easily.. is there something else that one should do to determine whether it is time to replace?

[312Hydro 474]

Well, the new snap ring I bought appears to be thicker and stiffer than the one that has been on there all this, time, so either the groove is worn out or the bearing is going.. so will check them both..

At the risk of displaying my profound ignorance of things mechanical, I have never replaced a bearing before it was really ready to go (i.e. squealing).. I assume I just need to clean it, grease it, and make sure it rolls easily.. is there something else that one should do to determine whether it is time to replace?

That's what i did . The bearing started to make a noise and I caught it in time , greased it .

[Kelly 1,029]

push on the stub as you turn it, if it feels bumpy or rough it's time to change it, it may spin nice with out putting pressure on it.

[dsholler 54]

well, the front bearing appears to be sealed.. it runs smooth, but it does make a bit of noise. Not fatal, but I figure it will need to be replaced one of these days. The PTO shaft on the other hand was full of crud... so I cleaned out the grooves.. the front groove was pretty square, but wear could be seen when compared with the rear groove. Also, the end of the shaft (where it sits in the bearing) was showing some wear as well.. I greased the needle bearing up and put it back together.. we will see if it holds tomorrow. Hopefully it will cut the lawn a few times, and in the meantime I will order a new stub shaft, and maybe a new front bearing as well.

Thanks to the folks who hang out on the chat room here late at night, for some quick and invaluable advice on how to get the thing apart.

[dsholler 54]

Thank you all for being patient with my silly questions. Now the only thing that seems out of whack is that the PTO gets quite hot. The snap ring is staying in the groove, and the PTO works (*just went and cut some of my lawn, it came out well, and I could not discern any slipping on the PTO clutch) but when I touched the thing after I parked it.. the PTO was very hot.. you could put your finger on it, but only for a second or two..

Is this normal from belt friction? or is there something wrong? I am asking because of course I have never noticed this before, but it may be what always happens and I am just ignorant of it.

I did test it once before, and I had mis-adjusted the brake so that it was still in contact with the disk when the clutch was engaged.. that made the PTO hot as well, of course, but this time I am sure I did it correctly.. and I tightened the adjustment on the linkage..

[312Hydro 474]

Thank you all for being patient with my silly questions. Now the only thing that seems out of whack is that the PTO gets quite hot. The snap ring is staying in the groove, and the PTO works (*just went and cut some of my lawn, it came out well, and I could not discern any slipping on the PTO clutch) but when I touched the thing after I parked it.. the PTO was very hot.. you could put your finger on it, but only for a second or two..

Is this normal from belt friction? or is there something wrong? I am asking because of course I have never noticed this before, but it may be what always happens and I am just ignorant of it.

I did test it once before, and I had mis-adjusted the brake so that it was still in contact with the disk when the clutch was engaged.. that made the PTO hot as well, of course, but this time I am sure I did it correctly.. and I tightened the adjustment on the linkage..

I'd say you have a bad bearing. That front bearing is probably dry, judging by the noise. You can carefully pry off the shield with a small screw driver and lube the bearing and replace the shield. Or,If you have a needle for your grease gun,carefully insert it under the shield ,grease and rotate the bearing grease again and rotate. This will buy you some time until you replace the bearing.

[dsholler 54]

Thanks Rich.. I think I will just let the lawn be long for the few days it will take to get the part. Is it possible it is the rear bearing? I wonder if I should just be paranoid and replace both of them..

[can whlvr 993]

i would replace both bearings,get good quality ones,dont buy the cheap ones that some places offer,and the heat is normal,thay do get fairly warm,as long as its not so hot its melting seals or the belt,but theres alot going on there so some heat is normal

[dsholler 54]

I think I will just get them from the Toro dealer. Presumably those will be of decent quality, and the extra few $$ would be worth that.

[Sparky-(Admin) 21,290]

I think I will just get them from the Toro dealer. Presumably those will be of decent quality, and the extra few $$ would be worth that.

Good move!

Mike...........

[dsholler 54]

Will I need a press to get the rear bearing in?

[Don1977 604]

Will I need a press to get the rear bearing in?

Check out this thread: