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TR# Thottle Linkage fix?

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newmexTR3

newmexTR3

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Hey guys,

Murphy's law strikes again. Getting the car ready tonight to go a Triumph tech session on Long Island in the morning, I manage to break my throttle linkage. The pin that binds the thottle linkage shaft on the firewall to the linkage arm is the culprit. For some reason I can't see the sheered pin in the shaft to push it out, so I'm thinking of just drilling a new hole.

Sanity check- I'm thinking of picking up a bit extender, drilling a new hole and using a new pin. This is a parking lot fix, so I'd rather not pull the carbs or anything more involved (thus the extender so I can get at the shaft). Any other tips, tools, or tricks anyone can think of to help me would be appreciated.

Cheers,
Gavin
 
I wish I could help, but I don't have a clue about the TR3 setup.

But not to worry, Randall or Don or Tom will be around soon, if some other knowledgeable TR3 guy doesn't come to the rescue first.
 
Just a thought : if you can't see the pin then you probably don't have it lined up right. Redrilling with the linkage at the wrong angle is likely to cause even more problems.

Personally, I'd do a little more quality time looking for the hole, so I could stick a piece of wire or nail in it. Should be easy enough to pop the linkage apart at the front carb, so you don't have to fight the carb springs during the hunt/repair.

When you do get it fixed, note that there is supposed to be a stop under the pedal, which is supposed to keep you from applying excessive force to that pin (and the rest of the linkage).
 
I had the same exact thing happen on my 3 to me last summer when I was adjusting my throttle linkage. I was testing out the pedal throw, when "snap", and the pin connecting the arm to the shaft sheared off. I gasped momentarily, as I began to think I was going to have to pull the engine out to fix it (That acclerator rod is a trick to remove; I can't see how to remove it with the engine still in unless you press out all the pins, which would be nearly impossible on the driver's side.)

However, I didn't need to. I did have to remove the carbs and intake manifold and then the four little sheet metal bolts holding the bearing housing to the passenger side firewall. Then I took my Dremel tool with a little wire wheel attachment and cleaned about two inches on the end where the arm is, and cleaned off the area to locate the pin. Then, because the pin was sheared, I was able to slide the arm up the shaft (towards the driver's side) to get enough clearance to remove the arm from the plastic bearing. Once it clears, you'll have more flexibility and movement on the rod. Once free, pull the arm off the end, and punch out the sheared pins from the arm. To get the pin out of the rod, I used a drift punch with a C-clamp to basically press it out (You'll need three hands and a monkey to do this--The punch will be on one side of the pin, and on the other I taped a 3/8" nut to the c-clamp so that the pin will have space to slide out. Holding it all together with your left hand, tighten the C-Clamp with your right). Get yourself a new pin, which Moss sells for about $1, get everything back together, and using that C-Clamp press the pin back into place. Don't press the pin in until the arm is on the shaft, and located in the plastic bearing.

I couldn't imagine trying to drill a new hole in place; too much room for error. The rod seems too small to accurately get a larger enough pin through. You could probably do it you used a small bit, but then the pin would be too small and snap almost immediately. Good Luck!
 
Gavin - how'd you come out? I second (third?) the above suggestions, especially about *not* trying to drill a new hole in that very cramped space.

The wear in my setup meant the linkage didn't line up, so it was really tough to get it back together; visibility is not exactly premium down there unless you pull the bonnet and suspend yourself over the firewall.

Tom
 
I appreciate everyone's advice. I had one of those "who's going to win- the car or me?" moments, so I ended up working on it in the parking lot until 10 in the cold. I went for the drill method, which was pretty easy with a 12" extension on a portable drill. I'm planning on completely redoing that part of the linkage very soon, so this is a temporary fix.

Got it working and then drove 1.5 hours up onto Long Island on Saturday morning for a tech session at Ratco. Got to meet BCF member Art for the first time in person.

Car ran poorly up there, but with the collective help of the group we got my Curto carbs working excellently. Drove back in a new car.

Today drove up the Hudson River valley, car running great. I'm glad I persevered. It was a true TR weekend!

-Gavin
 
We discovered that one of the needles wasn't seated fully (.25" off in fact). Once we seated it correctly, it worked perfectly.

I guess maybe Joe was a bit distracted as I was in the shop chatting hum up while he was finishing them up.
 
Glad it was that simple, I've always heard he does exceptional work.

I hope you weren't really 'chatting him up' as that probably would distract him!
 
newmexTR3 said:
We discovered that one of the needles wasn't seated fully (.25" off in fact)...
Click to expand...

Actually, it was probably closer to 1/8" too low, but we didn't measure it. :smile:

Gavin pulled the car into the bay and it was running on only three cylinders. We pulled the plugs, and the rear plug was fouled. Sandblasted all of them, checked the gaps and re-installed. It was now running on all four, but we couldn't get the rear carb rich enough. We just about had the the mixture nut totally unscrewed, but when the piston was lifted, the engine would die. That's when we suspected that the needle might be too low. Reseated it, adjusted the jet down 15 flats and the mixture was now spot on. :driving:

I'll tell ya, Gavin is a hardy soul using his TR3 as a daily driver here in New York winters.
 
Technically it's not a daily driver as I walk to work. It is my only car though. If it's wet and wintry and there's salt on the road, I don't drive it. This weekend was the first in about a month that I had taken it out in fact, because the snow had melted away and the roads weren't looking salt encrusted anymore.
 
Must be nice to be able to walk to work. Glad you're keeping the 3 outa the salt, so many nooks/crannies
 
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