Aw !@#$%@ turned PTO shaft into licorice twist

mvoght · Jun 2, 2004

Boy did I ever screw it up.

I majorly have been doing it wrong, or different equipment needs different rules.

20 minutes into mowing with my new 93" finish mower, I disengaged the pto as the deck was catching a log (too deep grass), did NOT cut engine speed and had the deck raised a bit and re-engaged PTO and BAM. There went my mowing plans.

The shaft looks like a piece of licorice. The u-joint is busted, link gone. I don't THINK the mower was damaged. I'll check it more closely tonight. The twist happened on the mower side, not the tractor side. The tractor side unlinked quite easily, but was damaged. I left the artwork at my mechanic's last night and called him this morning.

60HP tractor requires different operation than 16 HP tractor.

The neighbor put it in perspective for me though. Nobody was injured and it is relatively easy to fix, even if pricey.

Mel /forums/images/graemlins/frown.gif /forums/images/graemlins/blush.gif

Nasty135 · Jun 2, 2004

mvoght, Don't feel too bad although I'm sure you do!
I'll tell you about my little problem which will make you feel a little better, Mowing grass with my 6' RFM on my old MF135 no problem,well I decided to try out my new MF1433v with the old mower ,get it all hooked up(never used electric pto before first use with this tractor) turn it on everything fine it kicks in blades start turning,OK good, now lets mow mowing along oh about 150' or so and I hear this clunking chatter quick turn off pto it stops. Get off check everything looks ok start again,OK good mow a little ways and same thing... Long story shortened , Evidently pto shaft had to be extended a little further on new tractor than old tractor not much but just enough to stress the shaft causing it to split on the end letting the inner shaft spin inside the outer (chatter)..The whole time I was thinking that my new first time used pto had a problem NOT,$150 bucks later I have new shaft that obviously isn't too short to start with /forums/images/graemlins/smile.gif

normde2001 · Jun 2, 2004

"$150 bucks later I have new shaft that obviously isn't too short to start with"

Did you make sure the new shaft is not too long? That can be just as bad.

hazmat · Jun 2, 2004

Did you make sure the new shaft is not too long? That can be just as bad.


Mel as Norm mentioned - check the shaft length on your mower. If you don't know how, have your dealer help you.

I'd be surprised that you could damage the shaft by starting / stopping the PTO. The shear bolt or slip clutch should let go first.

Much easier to damage it by lifting it up & having it compress on itself if it were too long - especially while spinning.

Most PTO shafts have to be cut to fit. Several threads here on how - try searching for cutting PTO shaft, or PTO length.

tawilson · Jun 2, 2004

You didn't say but by the capitilized NOT referring to cutting engine speed I assume you know now that you should cut the engine speed when engaging and disengaging the pto whenever possible.

Nasty135 · Jun 2, 2004

normde2001, Yes I did have to cut the new shaft to fit, it has enough play to absorb the movement of the RFM moving in&out with out putting pressure on the pto bearing, Thanks /forums/images/graemlins/smile.gif

mvoght · Jun 2, 2004

Hmmm, I asked if it could be the wrong length, he didn't think that it was. But, perhaps I should have him check.

It isn't a brand new tractor, the only new part is the mower. The tractor I got used, a lovely Case 585.

Thanks for the additional tips....and stories of others helps. My husband was starting to give me grief, but I had to cut him off because he NEVER mows or drives the tractor, so I feel he doesn't get to criticize me...especially when I said upfront, I messed up.

Mel

slowzuki · Jun 2, 2004

Hey I use a cherry 585 from time to time! Definately need to lower the rpms, it has an independant hydraulic pto that engages quite hard.

I used to think it had a 2 stage clutch but using the bushhog the other day it really slammed it into motion.

mvoght · Jun 2, 2004

( Definately need to lower the rpms, it has an independant hydraulic pto that engages quite hard.
)

Now I learn!

Whew. Expensive lesson. $240 or something like that. I need to investigate if other brands would work...are the PTO shafts standardized?

Let's hope my first replacement lasts me several years.

Mel

nicklan · Jun 2, 2004

mvoght,
I did a similar brain fade this winter with my snow blower, I thought I had cut back the power, but it was still running around 1800 rpm, engaged the pto and bam! broke the shear pin. Difference is I got off light "this time" (and I emphasize "this time") /forums/images/graemlins/grin.gif

Nick