Is this working correctly? Hand throttle?

L

Late31ugh?

Junior Member
Hi I have a question about how the hand throttle is supposed to work. If I remember correctly the hand throttle actually adjusts the throttle 100% through its travel. Mine currently only works in the upper 10% of travel. The rest 90% of the movement has no impact on the throttle. The linkage coming off the steering column seem to move correctly. Then we come to the linkage that goes behind the engine. I think this is were the problem is. The linkage behind the engine and gas peddle do not move untill the hand lever is at the full throttle position. That seems wrong. Any thoughts of were I should start looking? Also the rod coming off the column touches the starter rod in the lowest throttle position I don't remember this happening before either. This is on a late 31 sedan. I had some work done could they put the wrong year linkages or rods on it?
 
Late31ugh? said:
Hi I have a question about how the hand throttle is supposed to work. If I remember correctly the hand throttle actually adjusts the throttle 100% through its travel. Mine currently only works in the upper 10% of travel. The rest 90% of the movement has no impact on the throttle. The linkage coming off the steering column seem to move correctly. Then we come to the linkage that goes behind the engine. I think this is were the problem is. The linkage behind the engine and gas peddle do not move untill the hand lever is at the full throttle position. That seems wrong. Any thoughts of were I should start looking? Also the rod coming off the column touches the starter rod in the lowest throttle position I don't remember this happening before either. This is on a late 31 sedan. I had some work done could they put the wrong year linkages or rods on it?
Click to expand...

There are differences in the throttle control assemblies over the years, but they all work basically the same way and there shouldn't be any effect from using the wrong one. The control rod lengths are the same in all years.

On a 30-31, the steering column can be slightly rotated. Perhaps yours was adjusted? If you had the steering column rebuilt or reinstalled, it's possible that the spark and throttle control lever arms are in a different starting position than before. This can cause the bell crank on the throttle control assembly to start its rotation far away from the accelerator pedal arm. This would cause the behavior you describe, where the hand throttle doesn't start pushing on the accelerator until quite late.

Bottom line, inspect the linkage between the bell crank, throttle control rod, and throttle lever arm. A common workaround, if you don't want to do surgery on the steering column, is to bend the control rod – this both shortens it and helps it clear the starter switch rod. Not strictly kosher but I've seen it in many cars.
 
Late31, as mentioned above there are several things which could cause trouble with the throttle assembly. If the foot throttle and spark advance work correctly through their full range, your steering column is probably rotated correctly. If the foot throttle works correctly, the rods and spring are probably OK.

Check out this thread from last year when I had the same problem:

https://www.fordbarn.com/forum/showthread.php?t=296545

In my case the problem was the vertical pin and the bell crank were worn badly. The play caused the problem you described. I cannot find a machine shop that will fix it so my solution has been to cut a small piece of brass shim stock and wrap it around the pin. I placed the bell crank over that and it now works as it should.

Let us know what you find with your car
 
If the throttle control bell crank has a good return spring on it then it can be difficult for the little short lever on the crank assembly to pull the main throttle arm much. A person can help it some by pushing the foot control to where you want it and then setting the upper throttle rod lever to hold it there. Keeping this stuff well lubricated does help. There is also the serrations on the control lever quadrant that can get worn and not hold position as well.
 
X2 on the above, I would also verify that the spark advance is working properly at the distributor to give the full 20 degrees there. I'm thinking that would verify the control column is correct???
 
the linkage can be bent with a clumsy motor extraction. The travel of the linkage to the carb
Should have adequate sweep to fully open, or close down the throttle.
I have cold bent the arm using the eye of a medium crescent wrench, probably better than using any heat IMHO.
 
Update and questions hopefully there is a simple solution. I was able to spend the afternoon working on the linkages. What I found was if I pull the pins from the two rod linkages that are on the end of the hand control leavers I can rotate the rod linkages and properly position them so everything lines up and moves as it should. The problem is now the pin holes in the rod linkages and hand levers no longer line up properly to lock it all in place. Has anybody else come across this?
1. Are the pin holes in the hand control levers different for the throttle and distributor? Can the levers be installed backwards in the steering column causing this problem?
2. Has anybody found the pin holes for the reproduction hand control levers and rod linkages not to be drilled correctly?
3. If the reproduction parts are not drilled correctly what is the best fix or who sells proper parts? Redrilling the correct holes looks to be the fix but the new holes will be to close to the existing holes weaken the parts or make elongated holes so I'm unsure how to proceed.

Any ideas?
 
Get a helper. Have the helper advance the handle about 25% and observe the little ball coming out of the steering column where the linkage attached. Then ask the helper to pull that handle down more, then all the way down. Work your way over to the carb from there. If that little pin that holds the arm on the shaft is sheered, the throttle pedal will work normally, but the handle will not. I bet it is something simple.
 
The pins are definitely not broken i pulled the out. im hoping the spark and throttle rods can be reversed in the column and the pin holes are drilled differently.
 
Late31ugh? said:
Update and questions hopefully there is a simple solution. I was able to spend the afternoon working on the linkages. What I found was if I pull the pins from the two rod linkages that are on the end of the hand control leavers I can rotate the rod linkages and properly position them so everything lines up and moves as it should. The problem is now the pin holes in the rod linkages and hand levers no longer line up properly to lock it all in place.
Click to expand...

I had this exact problem in my '29 coupe after the steering column was rebuilt. I don't know the root cause. Because it's a coupe, I couldn't pull the control rods without removing the entire column. And I just didn't have the energy to pull the steering column again with no guarantee of a fix.

What I did was, rather than drill new holes in the rods, I drilled new holes in the levers. I filled the existing holes with JB Weld and then marked and drilled new holes that lined up with the holes in the rods.

The risk when doing this is that it's pretty hard to drill new holes in the lever arms that are exactly aligned through the center and exactly the size of the pin. If the holes are off-center, the pin won't go through; if the holes are too big, the lever arm will slop back and forth on the pin and you won't have precise control.

The way I solved this was to tap the holes in the long control rods. Then I drilled oversize holes in the lever arms and replaced the pin with a machine screw. Tightening the screw then holds the lever arm in position.

Having said all that, if you're able to swap the rods and do more root-cause troubleshooting than I did, that would definitely be a better approach.
 
Hi i thought I'd post the fix we came up with in case somebody else has this issue. I made a template of both ends of the steering column and marked the position the hand levers and pins for the little levers needed to be in. Then we pulled the hand control rods out of the column and locked the engine end of the hand control rods in a vice and heated up a small section of the shaft with a hand torch with Mapp gas. The rod got hot enough to allow us to use the 90 degree bends as a levers to twist the rod so the pin holes lined up were we needed them. Now the pins line up as the originals did and the little levers on the end of are in there correct location and the hand throttle and spark now work properly.
 
From time to time I have to check, adjust on my '31 due to the steering column slightly rotating out of position, I don't know why, I have it cranked down real good, but it gets a few degrees out, and it becomes obvious it needs adjusted again, only takes a few minutes to do, but it's a necessary procedure.
 
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