The Stovebolt Site Forums The Parking Lot Big Bolts 1966 GMC Tilt Cab throttle linkage help

Hey guys,

I dragged home another toy. Its a 1966 GMC tilt cab with a 305 V6. Shes in overall pretty good shape. Runs but I'm pretty sure has blown head gaskets or something worse. Smokes white pretty bad.

Anyway, my problem at hand is the throttle linkage. When I press on the pedal, nothing happens. I think the pedal rod is compressing into itself - see the video and pictures below

Does anyone have a tilt cab they can take some pictures or better yet a video? Its been kinda of difficult to find any information on these.

Thanks for the help.


Video =>

Hy campbell45, I can't get access to any of your pictures or the video.

Camp
I have a 67 GMC tilt cab and have had that problem also. It works after some back woods Cobboligy was used and some homemade parts.
Get your links to work and I get some pictures of what I did after this weekend.
The best cure would be to rig up a cable linkage that doesn’t have the sliding rod system.
Read the story of this truck in my sig.

Don

OK I watched the video and I used a small hose clamp to make a stop when the cab is lowered. Also clean and used a light grease to lube the slide.
That worked for a while and then it acted up again. Made up a new pipe and slide rod. Repaired the foot pedal, it was bent when the stop was set in the wrong place. I also had to add a return spring or else the throttle would not return.
I have a full weekend planned and will get back to you Sunday?

Don

Found a couple pictures of my setup. This truck has the Magnum V-8 so it may be different from your V-6.
The whole linkage seem to be cobbed up from the previous owners before me.
Small town Volunteer Fire Department.

Don

My 69 Chev fire truck has a cable and I do not recommend it. The cable has way too much friction and even after spending a lot of time getting it as straight as possible and lubing it carefully full length, its only a little better.

From looking at Don's truck above and your pictures, I think yours is mostly correct. Like Don's, I think yours is missing a stop. The telescoping part is to allow the cab to tilt up, when it is tilted down, the linkage should bottom out telescope wise.

Make sure all the pivot pins are good, the linkage is in the right holes, nothing is bent. You may be close to working fine but missing a half inch somewhere that prevents the message from getting to the carb.

Don't go cable. I am working on a hydraulic setup but I don't know when it might be finished. I put one in a 65 Chevy Van I had, worked great. That one was made out of an import car clutch linkage and some cobbled up brackets.

Post more pictures, maybe someone will spot the problem.

I could not get your links to work here either, but they worked fine in the email notification.

sweep
Thanks for the heads up on the cable set up. I do know some later model vans had cable linkage that worked good.

On a side note, my first vehicle was a 65 Chevy van. Had a lot of fun in that van back in the 70’s.

Don

Guys,

Thank you so much for the help! I just tried to edit the pictures and video. I uploaded the video to youtube instead so hopefully you can see it.

Based on Don's pictures, that setup looks very similar to mine. I'll give a hose clamp a shot. I wonder what the original clamp looked like?

Be careful with the hose clamp. I set mine wrong the first time and when I lowered the cab, it bent the linkage bad.
So I had to fab up a new one.

Don

Got time today to take a few more pictures. The slide travel when the cab is raise is 6 inches.
As I remember, the tubing is 1/4 schedule 40 stainless. Then just a 1/4 rod that slides down the tubing when the cab is lowered.
Your V-6 may be different on the slide travel.
Hope these pictures help.

Don

Guys, thank you so much for the help.

I feel silly that it was such an easy fix... I switched the throttle rod position on the carb to a lower hole. Gas pedal works fine now other than a few small binds. I'll disassemble, clean, and lube.

Thanks again for the help!