Well, Mike, since you're the guy who controls the levers on this forum, and the guy who posted this non-Comet thread, I'll jump in with a tractor question of my own. It's sort of a mystery story that I'm looking for some detective input on.
I have a 1948 Ford 8N tractor. Ford tractors of that vintage are notorious for rear axle seal leaks that allow the brake linings to get saturated in oil, making them VERY hard to stop. Such is the case with mine. I was using a scrape blade near the pond at the bottom of a hill on our property, and started to climb back up the hill to park the tractor. I didn't have enough throttle set, and the tractor began to bog down as I started up the hill. I instinctively pulled in the clutch and stepped on the useless brakes and started rolling backwards down the hill. I let the clutch back out and popped a wheelie
, so pushed it back in and "feathered" it lightly until I could turn the tractor parallel to hill, at which point the engine stalled. After checking my pants and restarting the tractor, I discovered that the clutch would not disengage to put the transmission in gear. I finally cranked it in neutral, idled it fairly low and forced it into 1st gear, then revved it up and climbed the hill back to the house.
I thought I might have broken the clutch fork shaft or sheared the pin on the fork, but the shaft, which passes all the way through the casting, rotated equally on both ends. I didn't have a way to check for a sheared pin, but it acted like the throw-out bearing wasn't pressing far enough in on the clutch to disengage it. I decided to adjust the 3/4" free-play out of the clutch pedal so that all of the TO bearing's travel would go into disengaging the clutch, and see what would happen. If the pin were sheared, I could expect nothing. If it weren't......? To adjust the free-play, I had to disconnect the linkage, which allowed the fork to move away from the clutch more than normal. I reassembled it with no free-play, cranked it up and everything worked just fine!
I adjusted the linkage again to add the free-play back in, and everything worked just fine.
I turned it off, scratched my head and left it alone for a few weeks. The next time I tried to use it, the clutch wouldn't disengage again and I had the same problem all over again.
Now, after talking to some people, I've developed a hypothesis, which I offer for your critique and input. Hypothesis: When I popped the clutch on the hill, I tore a section of the clutch disc. The torn piece wedged between the pressure plate and an un-torn section of the disc, effectively making the disc twice as thick at that point and decreasing the pressure plate gap to zero.
Assuming the disc is riveted and not bonded, and that one end of the torn piece is still riveted to the disc, the torn piece could then rotate on the rivet. Further,
assume that if the engine stopped with the clutch disengaged and the torn piece at the top of the disc, the torn piece could rotate to fall between the plate and disc, locking up the clutch. If the engine stopped with the torn piece on the bottom of the disc, the torn piece would rotate away from the plate, allowing the proper gap between disc and PP. Now,
assume all this assuming were fact, and the engine stopped with torn section located at the bottom. When I adjusted all the free-play out of the pedal, it allowed enough additional travel of the PP to release the torn piece and rotate out of the way. I fire it up and everything works fine, centrifugal force keeping the torn piece rotated out of the way. I stop the engine, and the torn piece
happens to be on the bottom again, so doesn't rotate into the gap between disc and PP. I add the free-play back in on the clutch pedal, fire it up and all's well. I stop the engine again, and the torn piece happens to be on top and rotates into the gap again. I start it a few weeks later and can't disengage the clutch. Plausible hypothesis, or am I nuts?
I suppose the only way to get to the bottom of the mystery is to do the autopsy and see what I find. I've been putting it off since you literally have to split the tractor in two, separating the front half from the back half, to get to the clutch. I would be interested in any theories or suggestions you may have.
Jim
or it will be leaking like sieve.
