Originally Posted by windmill
Here's a Gravely slip clutch, dont have one loose to weigh, but I would guess it is under 4 lbs.
Looking at the "teeth" on the Gravely, it looks like it only works in one direction. I imagine the matching part also has the saw tooth cut.... err, I guess when enough torque is applied the teeth ride up on each other and force the clutch to open, tightening the bolts increased spring pressure to resist opening the clutch...
So if the wheel driven by this unit (hack wheel) has traction and the tug wheel doesn't, this might actually work against you if the spring pressure is set too low. (Cutting power to the high traction side.)
And since there is no way to disconnect power to the tug wheel alone, sharp right hand turns are still going to pit your turning efforts against a locked differential, while left turns should allow the Gravely to work. (This is where I start wondering about consistency, I don't see it performing the same in mud as it does on hardpack... it's too dependant on the spring pressure, although maybe there's a happy medium??)
Uhg... I need to go look at one again. It's been years since I've been near a tractor.
But... I do have something similar out in my shed. Instead of having the saw tooth shaped teeth they are triangular, so will slip in either direction. Not sure what it came from, but it's only about 2" in diameter with a 3/4" shaft.