34 clutch linkage pin

JimG

JimG

Senior Member
I was suddenly having trouble with my clutch not wanting to totally disengage. Felt like something broke, as it came on suddenly. I took the car to a guy Charlie ny recommended, as I thought I was in for taking the clutch out. Turns out the pin that holds the clutch lever to the shaft coming out of the bell housing had broken. This is part number 352581-S off the enclosed diagram, but the diagram is for a 1935 car. Does anyone know what the original diameter of this pin would have been for a 1934 car, and what the material would be? The shop where I have the car said they have reinstalled a 5/16" hardened bolt in place of it. Said what was left of the old bolt looked like 1/4", which wore and eventually broke. Should I be concerned that using a hardened bolt (don't know if he is using Gr 5 or 8) would cause more wear on the linkage arm and shaft. If it is going to wear, it would be better if the bolt wears. They probably wouldn't be too happy if I asked them to change it to a regular bolt at this point. I only drive the car 500 miles or so a year, so maybe it doesn't make a lot of difference, but you do use the clutch a lot in normal traffic.
 

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352581-S is actually a rivet and would be a softer material than grade 8 or 5. The original rivet may have been removed to replace or repair something in the past. I've had to remove those rivets when working on one of my 35 transmissions, but can't recall now if they are 1/4" or 5/16".
 
Except for '32s which used tapered pins, from '33 on up 1/4" rivets were used for both that arm and for the fork near the center of the shaft with variations in length depending on the pedal configuration. A failure of one of those rivets is a pretty rare occurrence and it sounds like your original may have been replaced with a bolt at some point.
 
If there is no play with the new bolt installed, there is no need to worry
about the use of a grade 8 bolt. The original soft rivet would have been swedged real tight so as to expand it to literally "fill" the hole with zero play. Many years ago I actually drilled and tapped that rivet hole for a threaded allen head hex screw and nut. 40 years. No problems.
As John Lennon said, "Let it be."
 
Thanks for the quick replies, guys. The pin didn't look like a bolt in the drawing. Now that I think about it - 1930's - rivets make perfect sense. It was state of the art fastening at the time for many joints. A good rivet is as good as a body bound bolt. I didn't want to be an idiot over this, but also didn't want to install something that was going to give me more trouble down the road.
 
DavidG said:
Except for '32s which used tapered pins, from '33 on up 1/4" rivets were used for both that arm and for the fork near the center of the shaft with variations in length depending on the pedal configuration. A failure of one of those rivets is a pretty rare occurrence and it sounds like your original may have been replaced with a bolt at some point.
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DavidG, with all due respect...everything I've checked regarding specs on pn 352581-S indicates this to be a flat head rivet/pin, 5/16" dia. x 1-1/2" long. Also, a check of nos '35 clutch fork and clutch release arm that have, the rivet/pin hole diameters measure 5/16".

JimG said:
Thanks for the quick replies, guys. The pin didn't look like a bolt in the drawing. Now that I think about it - 1930's - rivets make perfect sense. It was state of the art fastening at the time for many joints. A good rivet is as good as a body bound bolt. I didn't want to be an idiot over this, but also didn't want to install something that was going to give me more trouble down the road.
Click to expand...

Jim, I have to agree with the other replies here that tell you to leave that 5/16" bolt in place.
 
John,


Thanks for the correction; right church, wrong pew. I'm still down south away from my car stuff so I used the top of my head, which is less reliable with each passing day.
 
Rivets have the advantage of filling the hole to a tight fit before forming the buck tail. They start out in a relatively soft state but work harden quite a bit during the driving process as the grain bonds are pushed closer together in the metal.

The key is a tight fit. Tapered pins were good for this but took special tooling and likely cost a slight bit of penalty in time to produce. It might have made a half cent of difference in production cost of the car but after a million cars, it starts to make more sense.
 
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