Sunday afternoon I was ready for a drive after having done a host of chores on the mostly 1923 Runabout. The motor started normally but suddenly stalled when moving the lever from the brake position to neutral to back out of the driveway. Three restart attempts were made and the car lurched forward each time. It was locked in high gear! Having finally figured that out, using the clutch pedal allowed the other heal to operate the starter. I had a pretty good idea what had happened and decided to have a drive using the clutch pedal for neutral. As it happened, I did not get too far for other reasons detailed in another thread and returned after just a few miles. Too bad as it was a lovely afternoon!
Here is what I found after removing the floor boards:
Here you can see where the shaft has been turning in the hogshead:
The high gear adjustment screw had been riding half way off the cam ever since the car went together and it was another detail that I had intended to look into once more basic stuff had been attended to. These things have their own will and this issue is now front & center.
I was able to free the jam by moving the lever all the way forward and adjusting the shaft by hand. What holds this shaft in position? How does it get fixed?
Vintage Paul, a pedestrian again
Often the clutch bolt will not line up with the center of the brake lever, so I bend the clutch arm until the bolt is in the center of the arm.
You asked what holds it in the correct position, not much, as far as I can see the forked arm is the only thing holding it in position...
Paul. a question for you, what's the hot spot on the centre of the drive plate, is the drive shaft welded to the plate?
Also the band looks askew. Scott
Paul - I believe it's just the clutch fork that holds the shaft in place. I don't recall any stops off hand. Perhaps the fork or shift slide is worn and allowing the shaft to move in and out.
Larry Blair at the Tin Shed did the machine work on my trans and then the hogshead. One of the things he did was to machine a new shaft for something in the hogshead. The old one was BENT! I got the hogshead back all painted and ready to install complete with new seals on the shafts.
Larry did the machine work on the trans, but I assembled it. One of the things he did was to weld some bits together so they wouldn't come adrift in service. Here is a pic:
I'm not sure what the brake band being askew means, I never noticed it before.
I wonder if some sort of collar might be fitted to the inside to hold that shaft where it is supposed to be?
I had that problem before. I solved it by turning the clutch arm bolt around and used the head to make contact with the cam. It has a much larger bearing surface which reduced the wear on the cam and actually made the cam action much smoother. Seeing the benefits, I now do it to most of the cars I work on for myself and others.
I like that solution. Have you ever had a shaft/cam move as far as this one has?
How are the ears on your hogs head? And are you using the wood blocks on them? If The one on the drivers side is bent or broken it will change the position of the clutch lever. Also if the frame is spread it could cause some alignment problems. Is the cam on the cross shaft straight? You might want to measure the distance from the drive shaft at the U joint from both sides of the frame. It should be the same if the engine and transmission are in alignment. Also what Tony posted. It could be caused by any of the above or a combination of them. When not quite as far off as yours, some have had success by reversing the bolt so that the head rides on the cam.
The bolt most likely slipped off the cam at some point. I can't tell if the cam is bent. Check to make sure the control shaft is bolted tight to the frame and that it isn't sliding back and forth instead of the clutch shaft.
Paul: Yes. Once The bolt was reversed, I bent the cam so it was perpendicular to the shaft as it should be. I also ran a file over the cam to remove any of the burrs and high spots that the threaded end of the bolt created. Once the cam was smooth, the head of the bolt found its own path on the cam and didn't appear to be as sensitive to any camber in the cam face.
When I had my bolt turned thread end down I had that happen. Just turned the bolt around. Don't forget to use the jam nut! I forgot and lost mine, 2x's! Before you put the bolt back in, round over the edges so it will ride up onto the cam easier.
Paul, why is the driven plate shaft welded to the plate? Were the rivets loose? Did you check the plate to make sure it was not cracked or warped as a result of heating it?
I found that the shaft would work it's way out and even after I put the bolt head down to ride on the cam it was off center enough to be a problem. I solved the problem by hooking a spring over the clutch arm and attaching the other end of the spring to one of the bolts holding the hogs head to the crankcase so the spring is always pulling the clutch arm sideways over towards the transmission. Works like a charm but it didn't do anything to keep the oil from weeping through the worn clutch shaft!
Val, I love that solution. I;ll see if I can rig up something like that after turning the bolt upside down. Do you have a picture of your installation?
Stephan - I o not think the rivets were loose but possibly Larry saw something he did not like. He did say he did this as a matter of routine. I did not think to check it for straightness. Would that affect the high gear jamming issue? The transmission otherwise seems to work fine.
No, the strightness will not affect the clutch but, it will affect how long your crankshaft lasts.
Paul, I will mention because no one else has, but the above picture only shows one cotter key in the clutch adjusting arms. I'm sure the photo was taken before final assembly and I assume you've got the other two in place.....
Paul, I am sorry but I don't have a picture and right now the care is 250 miles away. But I am afraid that even if I had the car with me I wouldn't be able to get you a picture as I have never been able to post pictures on the Forum because my grand kids tell me I am computer challenged.
Sure thing Joe, the other two were installed before final assembly.
I had a phone call yesterday from a fellow who reads but does not post on this forum. He had a similer problem and solved it by constraining the movement of the shaft with a couple of split collars, one inside, one outside.
With this and the simple spring we have two potential solutions. I still have to wonder what is supposed to hold this shaft in place? Most Model Ts do not have this issue, what's the difference?
that's an awful lot of movement...the bronze "horseshoe" collar floats in the groove and may well be worn enough to allow excessive side motion (Val you may be exacerbating that wear with your setup?).
As an aside, I'd suggest that you do not use the brake lever to pull into neutral...hold in neutral with pedal and allow the lever to then hold it there. The cam on the brake arm doesn't really seem to be designed geometrically to "cam" the clutch shaft into neutral without an awful lot of effort and torque on the cam. I wonder if along with inverting the bolt, this will solve your problem, as the shaft will likely locate itself where it wants...just bend the cam to match.
My hogs head is so worn that I am not worried about exacerbating the wear. I am just trying to keep the car on the road while I locate a replacement hogs head for my '27 that I can swap out for my worn one. Oddly the wear seems only to allow the shaft to move out from the transmission housing. With the spring the shaft centers right over the cam.
Saturday the bolt was removed and the threads chased and the head ground into a smooth arc on a bench grinder, file & with sandpaper.
Here is the new finish on the bolt:
After installation the action of the lever was much nicer than it had ever been before, nice and smooth. Adding some grease made it even better!
Here is the completed job:
I'm going to try it just as it is and see if a spring or collar will be needed to hold the clutch shaft in place. I wasn't able to drive the car this weekend as it is down for other work right now.