Failed Throttle Linkage

[HarryD]

I was doing an HPDE at The Ridge Motorsports Park in Shelton, Washington which is a few hour drive from my home.

On my second session, things were going great and all of a sudden I have NO throttle. My foot went to the floor, I felt no resistance and the car just kept slowing down. I was able to get the car safely off of the line and they black flagged the session to tow me off.

I jacked up the car and verified that all of the bell cranks I could see front to back were intact (I removed the pedal board to look behind the gas pedal). I pulled the hand brake, heater control, hand throttle assembly to see if there was something there. In the process I dropped the little hand throttle collar (Parts 90 and 91) into the tunnel (arrrrgh). I pulled the rear inspection plate in front of the rear seats. Nothing appeared out of place. I had some one step on the accelerator pedal and notice that everything up the little bellows (Part 12) under the car (and over the transmission mount) moved. Nothing from the bellows to the throttle body moved. After much fiddling around, it was apparent that something in the bellow was broken.

I disconnected the bell cranks at the accelerator pedal and outside of the motor (part number 11). I pulled the bellows off the car and found the broken piece. Part number 10 on this drawing.



It had separated into two pieces.





Being I need to be able to get my car home, I figured I needed a quick fix. Fortunately, AR Motorsports (Portland Oregon) was on site for driver support and emergency repairs. I showed them the two parts and how I needed to make them one. I asked if they had some safety wire so I can hold the two parts together. They said they did so I did that "arts and crafts" project.



I reassembled the car to a drivable state. I then drove carefully home (no abrupt accelerator movements).

Made it safely home. I was able to source a new coupling from my FLAPS with delivery the next day. It arrives as promised. Note the new part has the rubber encased on a metal sleeve to keep the ends from separating from the body.



I disassemble throttle linkage to install the new part. After several hours of "fun", good news, throttle linkage works again!

Bad news, I was unable to retrieve the hand throttle collar and longer have a working hand throttle. Also, at this point in time, I am stymied by how to get the linkage bellows (part 12) back on the opening to the tunnel on the car. These items will need to be addressed on a later day.

[bob joyce]

i think everyone has had that fail.
until they replace with the upgrade part

[HarryD]

i think everyone has had that fail.
until they replace with the upgrade part

But 50 years is a pretty good run.

[Chuck Miller]

i think everyone has had that fail.
until they replace with the upgrade part

I had my OE part fail on the way home from the track about 25 years ago ....

The only real DNF I've ever had in my old car..... ... Knock-wood ...

[nickb4]

I too dropped that same part into the tunnel and of course it found its way to the exact middle between the hand brake and shifter openings. Took a while of poking and prodding but I was finally able to fish it out.

As far as installing the isolator boot onto the car body, Ed Mayo had published some instructions on that a while back where he applies silicone paste to the end of the boot and carefully pries the boot back onto the body using a cotter pin extraction tool. It made the installation, in my case, fairly easy.

[zenithblue71T]

Well done on the macgyver fix. Congrats man. This is the first thing I upgraded on my 71T, 23 years ago.

I’m on my third clutch fork pivot bolt though. That part just keeps failing ever 8 years.
https://www.autohausaz.com/pn/91111677211

[HarryD]

I too dropped that same part into the tunnel and of course it found its way to the exact middle between the hand brake and shifter openings. Took a while of poking and prodding but I was finally able to fish it out.

As far as installing the isolator boot onto the car body, Ed Mayo had published some instructions on that a while back where he applies silicone paste to the end of the boot and carefully pries the boot back onto the body using a cotter pin extraction tool. It made the installation, in my case, fairly easy.

Thanks for the suggestions.

The boot is difficult get on when you are in your back with the car inches from your face.

I will need to do the fishing expedition as well.

I will be over to a friends place tomorrow who has a lift. It will get done.

[dummkopf]

I guess I need to check mine, although I think I have done this. Most problem I have had was a ball that popped of the carb linkage and needed help from a zip tie.

[HarryD]

Well done on the macgyver fix. Congrats man. This is the first thing I upgraded on my 71T, 23 years ago.

I’m on my third clutch fork pivot bolt though. That part just keeps failing ever 8 years.
https://www.autohausaz.com/pn/91111677211

Thanks.

It was that or a 2+ hour tow home. A very nervous trip home.

[HarryD]

Replaced the failed part and the three throttle rod bushes. All is well again.