PTO adjustment?

[Searcher60 209]

On the engine pulley PTO, with the PTO disengaged, is there any specification for the air gap between the pulley face and the friction material? I have about 3/16”, and my friction material is about 1/8” thick, maybe a little more. Is the 3/16” air gap normal? Do I adjust the ASM bracket clearance to .012” with the PTO engaged? Thanks!

[Lee1977 7,052]

The 3/16" should not make and difference. I normally run my loose never measured it.. The rod adjustment is to adjust the clutch so it doesn't slip when engaged.

Here is two of mine. One looks to be 1/8" and the other close to 3/16" both have decks and I had to pull the bell out by hand to see the gap.

[lynnmor 7,607]

You adjust that little PTO brake pad so that it has .012" clearance with the PTO engaged, that way you will never have more than .012" clearance and the brake will stand a chance of slowing the pulleys when the PTO is disengaged.

[Gasaholic 257]

Yup. Lee and Lynnmor got it covered pretty much - If your machine has PTO brake, the way I always did it was, you adjust the pto engagement lever just enough to engage PTO without slipping under load (Over-adjusting it causes excessive side loading on the engine bearings and PTO center bearing as well as stub shaft bearing and PTO components, which is undesirable) , and then if it has a PTO brake, with PTO engaged, adjust brake to a .010 - .015 clearance , which when PTO is disengaged should bring the PTO stack pulley into the brake pad. Not all machines had the PTO brake on them... so those that did not have one, PTO was just adjusted to apply enough pressure to engage without slipping (and worn or burnished clutch linings often lead to over-adjustment to "fix" slipping, which usually made things worse than better - Like Heavy duty trucks having to stop at the top of a long grade to allow brake cool down - hot brakes or friction linings , and manual clutches, or those that got oil on them were decidedly ineffective.)