PTO Clutch adjustment

[repete]

I have a couple clutches on implements and was wondering how folks go about adjusting theirs. On mine I use a point and shoot thermometer. I run the implement hard and see that the clutch warms up some indicating a slip. Then back down the load and see that it cools again.

When my brother picked up a tiller he said it would kill his engine if it was asked to do too much. I thought it was odd that it did not slip but maybe it was set for a higher HP tractor. We loosened all the bolts that set the spring pressure and it still did not release. We told the dealer of the issue and they gave us a new clutch saying they had never seen that happen before... It was rusted solidly together. It was a new tiller but was left outside in the rain at the dealer.

 

[wmfamily]

The slip clutch should have specific settings based on the brand. There should be settings documented in the user manual. The slip clutch on my mower calls for a 4mm gap between the front plate and the back plate with the clutch plates sandwiched in between. Every spring I loosen it up all the way, run it for a bit to scrub the junk off, and then set it again. If they sit outside too long without cleaning the crud off the clutch plates can get too rusted and require replacement. After years of use they will need to be replaced. The setting wouldn't be based on the tractor HP since the implement should be sized for the required HP, not too much or too little.

 

[SmallChange]

he said it would kill his engine if it was asked to do too much

I think this isn't good enough, because there's inertia involved too. An ordinary lawnmower (with the blade bolted directly to the crankshaft) will stall the engine if you hit something very strong and immobile, such as the edge of a manhole cover. But it may do plenty of other damage at the same time, because the parts are moving so fast. The forces could briefly become tremendous. It depends how suddenly circumstances would require the engine to go from operating speed to zero.

The PTO clutch limits how big the forces can get anyplace upstream, and provides partial relief anyplace downstream.