PTO disengages during mowing

[Mg181 4]

1991 312-8 w 42inch RD mower owned since new. First time I ever remember the PTO lever disengaging randomly. At first I thought heavy thick grass, but it happens on fairly easy heights as well. Where should I look first to solve problem? Thank you

[gwest_ca-(File Mod) 11,301]

Tighten up the trunnion at the front of the pto lever two turns and if more is needed 1 turn at a time. You will see the edge of the friction material on the pto. When they slip they wear. Don't let it go too far so it scours the plate.

[Rick3478 434]

It's an over-center design, usually pretty trouble free, but parts wear with age.  Clutch disk wears thinner and lever bushings get sloppier, so if it isn't tight enough it may fall out of engagement.  Check the condition of parts, if you're lucky may just need to tighten up a thread or two on the trunnion.  Also possible to have something jammed so that it isn't moving to full on position, like sticks or other debris, bent safety switch.

[8ntruck 7,496]

Check the C clip on the outside of the shaft that pushes the clutch to engage the PTO.  If that clip comes out of the groove in the shaft, the shaft won't be pushing on the clutch to engage it.

[lynnmor 7,645]

I bought two PTO bells from a good vendor on here, both had considerable wear on the outboard end, of course he replaced them.  I have seen others with this strange wear and finally came to the conclusion that folks run the PTO's with the pins or clips wasted.

 

[peter lena 9,140]

@lynnmor  agree with the functional detailing on  the lever set up , go from the starting movement point , on the battery rail frame , area, washered up , every  movement spot , steel washers / plastic , silicone grease . as said , that entire set up is a gold mine for improvement , also changed the trunnion to a HEIM JOINT , very solid smooth , pete

[aemsee 93]

I was just dealing with this after I installed my tiller for the spring planting. Then I realized I forgot to reinstall the lower clip on the pto horseshoe bar. Sucks getting old, lol.

[tunahead72 2,522]

I just encountered this same problem this afternoon while I was mowing.  I heard a noise, and didn't realize at first what had happened, and then when I engaged the deck again the lever snapped back hard into my sore thumb, got my attention real fast!

 

Tightening up the trunnion 2 turns like Garry suggested seems to have fixed the problem, but I do want to check things out more thoroughly before I mow with it again.

 

@Mg181  Did you get your problem fixed?