TR6 TR6 Throttle Linkage Bent?

[Webb Sledge]

My throttle linkage has been really screwed up recently. The accelerator pedal bar slips inside the control lever, and I think it's because my "control rod" is bent. I'm talking about the piece of bar that connects the control arm and the pedal running across the engine bay to the rest of the linkage. Is it supposed to be bent? The bend in mine is fairly signifigant, and I think it might be part of the reason my pedal isn't returning properly, and why I can never seem to get the linkages set right so I get full throttle when it's floored.

 

[swift6]

Yes there is a fairly significant bend in that rod. The TR throttle linkage was not Triumphs best hour in design. Or five minutes for that matter. Meticulous set up described in the Bentley can nearly optimize it but it's still a pain. Also, make sure the bolt in the firewall below the accelerator pedal is not out to far and preventing full throttle. /ubbthreads/images/graemlins/cheers.gif

 

[Brosky]

How are the bushings going through the firewall on each side that support the throttle shaft on each end? Is it tight and not moving up and down in these bushings?

 

[Webb Sledge]

The bushings are tight and brand new. I don't know... my linkage is out of wack. It's not the bolt under the pedal that's holding it out, but I'll have the pedal at like 3/4 the way down, and the carbs will be at 3/4 throttle, and then I'll push it the rest of the way down, and the carbs will stay at 3/4 throttle (I've watched it do this with the car stationary). Something is binding or just not right. Half the time the throttles don't want to return, either. I have the correct spring on their, and the carbs and new and have good springs in them, but something on the linkage is keeping them from popping back. I can put my foot behind the pedal and pull out on it, and it returns to a normal idle, but that gets old quickly.

 

[Guest]

Webb, if we are on the same page, I don't think that the rod running along the firewall is supposed to be bent at all. Maybe you are talking about something else and I don't understand. At any rate, disconnect the carbs (I think you are running DGV's) and watch the mechanism work without any resistance (carbs holding back) and see what is happening. If all looks normal, you might do as I have done, resort to stiffer springs both the one ones above your foot and the one at the end of the shaft where the linkage starts. My triple carbs are a little balky and I needed more return-spring-action to prevent an open throttle. Use lots of lubricant.

Bill

 

[swift6]

Lets make sure we are all on the same page here. By "control rod" I'm assuming you are meaning Moss Part #676-030 (first catalog that I grabbed NFI). The Control Rod Assembly. This piece is bent. The rod that runs parallel to the firewall, through the bushings and all is considered one part with the accelerator pedal. This should be straight between the firewalls but can often be bent if not removed during engine installation or removal.

Further up the linkage, the control rod assembly attaches to the bell crank lever. There is a throttle stop that keeps that bell crank lever from "going over center". If that throttle stop is gone and the bell crank goes over center, it will not return on its own.

On the other side of the bell crank is the "control link" this is what pulls down to make the throttle shafts rotate. the control link and the control rod should both be adjustable. They can all contribute to lack of full throttle. The Bentley does have a good section on this and how to set it up properly.

If you are running DGV's then I don't know what is the same or different from the standard triumph linkage.

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