Hello out there....my clutch pedal action changed drastically recently and the usual is an old clutch cable giving out...well so far that is not the case and I even have removed my clutch pedal cluster thinking it was shot but now that it is out I compared it to my brand new pedal cluster on the shelf and they are identical in spring tension and other aspects...so basically my current pedal cluster is as good as new....so what to do next? I have heard of a problem with the braised in tubes in the tunnel for clutch/throttle cables that give out....can anyone please comment on this issue and how to fix? I am somewhat anxious about this repair and don't really know why....please someone tell what they know about this issue....thank you very much!!
gg

First look at the rear firewall to see if the end of the tube is solid there.

If so, then the other area is within the tunnel itself. Here are a few pictures I collected of the inside tunnel:



Here is a what it is supposed to be. This view is looking toward the back of the car.

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Here you can see how the tube has detached from the driver side of the center tunnel.

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Another shot of the tube being attached to the wall. Now looking towards the front, the tunnel having been cut at ~shifter level.

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Here this one seems to have been repaired with an extra clamp too.

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I had to repair mine but unfortunately I don't have pictures of it. What I did was to drill a couple of holes in the side tunnel where the u clamp is touching and I plug welded it. I was able to push back the tube in place via the shifter opening. Not sure this description is clear...

Thank you very much everyone....NEED MORE....not really getting the picture so to speak....maybe tomorrow it will clearer to me...thank you thank you thank you !!!!!
gg

Ok....I am starting to get it....I bought a borescope this week so I will give it a good look tomorrow.....the three A's as we say.....awareness-acceptance-action....who boy!!! Action should be a new experience!!
gg

My clutch tube was completely detached at the front end, so I cut an access hole in the tunnel and fashioned a clamp made from an electrical clamp part. Bolted on with 1/4" bolt
I also had to re-weld the tube at the firewall.

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This one is mine

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Tunnel was transplanted from a different parts car into my rustoration. Control tubes were fabricated from new metric tubing from Restoration design.

The clutch tube anchor is overkill. Belt + two pairs of suspenders . Two welded brackets + a couple dabs of braze above and below the tube directly to the tunnel. I wanted to make sure it never has to redone in the next 50 years because it’s such a miserable job to fix when it breaks loose up there.

R/R the shift lever assembly for access. Put a #2 phillips screwdriver in the end of the tube to stop the weld, drill holes then plug weld the tube to the side of the tunnel from the outside. No need to cut the tunnel.

The front is the most common detach point. If you unbolt the shifter base from the tunnel and rotate the base 90 degrees you can see the tube and its attach point. Step on the clutch pedal to verify its condition. If it is detached you can place a U-bolt over it to secure it to the side of the tunnel if you don't have a welder. If it has detached from the center section you can see it from the top of the tunnel directly aft of the seat backs. IIRC the wire bundle needs to be shifted to one side to expose the opening. That one can be re-attached with a J shaped bolt if welding isn't an option. The rear attach point can be checked at the point it exits the tunnel. Again if welding isn't an option you can rivet a drilled out plate to the firewall after sleeving the tube so that it protrudes into the engine compartment.

read the repair procedure in the tech tips 700 appendix


We have repaired them successfully for the last 48 years using this method

There's some pictures of the clutch tube in my thread. Follow the thread for a couple of pages for more pictures.

Spoke's Progress Thread

Here's a picture of the tip of the clutch tube. I cut holes out for access then speed nutted them back on.

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This repair is what I did some 4 years ago. Easy--easy fix.

Thank you all very much!!!! So my new favorite toy borescope showed me today that the clutch cable tube is intact in the exact place it is supposed to be....yay!!!! Thank you very much for posting the good pictures!!! I disconnected the clutch cable front and back and it does not budge in either direction...hmmm?? The back end of the cable shows no broken strands so I will remove the entire cable tomorrow....we shall see?? My current pedal cluster tested negative for any defects so what else am I looking at for the cause of my clutch pedal failure? Once I get the cable out I should know better but so far the cable looks in great shape....gotta' love these cars!!! I am relived that I may have dodged the tunnel repair but what the F is it!!
gg

As clutches wear the pedal pressure release force goes UP bigtime.

The BMW M3 has a problem with the plastic clutch pedals distorting so badly because of this the pedal often has to be replaced when you do a clutch job.

I tell all of my clutch recipients that initially the new clutch will have a pedal SO SOFT that they will think the new clutch is not strong enough.

I advise they will firm up quickly over the first month and all will be normal.

During use the increase in pressure plate operating force going up slowly most users do not notice the clutch takes twice as much pedal force as it did when it was new.

This additional force bends stuff, breaks clutch release forks, and wipes out cables.

You might have an old clutch that requires excessive force to release and it's trashing the cable.

You might just have a bad clutch cable. I thought you mentioned multiple cable failures, but that info is not in this thread.

Jumping from a car with a stiff clutch into a car with a normal clutch will easily demonstrate the difference.

If this is the first cable in a while, then replace and see how long it lasts.

I see the "stiff clutch" phenomena quite often.

I've also noticed clutches in the older cars (914, Z-cars, etc) would wear out in 50-70k and lots of new stuff lasts 150K+.

I have one customer who owns a 5 speed Toyota Truck who is the original owner on the original clutch at 540K!
It's stiffer than shit and feels "rubbery" during engagement.
I advised him to let NOBODY but him drive it as I believe it won't last a day with another driver...

I want to thank the previous posters in this thread. I was not aware of the second (in the tunnel) failure point and seeing all the different ways of addressing this issue is greatly appreciated!

The front tube repair in my 6. Put a drill bit in so the weld would not blow through

Bob B

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So making progress on my funky clutch pedal issue and dodged the tunnel/tube nightmare so still trying to solve the problem....decided to just remove the clutch cable and have a good look....well it won't come out the back end of the clutch cable tube??? I hear the end of the cable hitting the back of the tube but it won't come all the way out....hmmm? Must be something in there blocking the end of the cable from getting through....I wonder what it is?? Appreciate any thoughts?
Thank you very much,
gg

Try rotating/turning the assm while gently pulling and pushing it until it will pass. That fitting on the front end needs to be aligned with the offset in the tube. I didn't read where you confirmed the center spot weld was intact.

Maybe something went inside your clutch tube like old nut, that is blocking inside?

tunnel lines for your reference.

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It's possible someone repaired it before and at the back of the car where it goes through the firewall, maybe there's a piece of slag from welding. My picture above shows a drill bit put in the front of that tube so it wouldn't make slag. Don't know how you fix it for sure but if it was mine, I'd figure out how where it was knocking. Probably cut the cable and run it back out the other way and clear the jam up point. Measure it with a wire from the back.

Bob B

And maybe use inspection camera too to check what is in there.

We have also seen the inside of the tube corrode a little bit, preventing the ferule on the end of the cable from going through the tube.

Going the other way, some cables have ferules that are a little wider or longer than others. The longer ones can get stuck where the tube makes a very slight S-bend back near the firewall.

--DD

"The last 48 years" thanks doc

I don't have a suggestion for your next steps on the clutch but...this thread is a good nugget of information. I didn't know about the tunnel tube breaking off. Just ran a scope and see that mine needs to be fixed.




So the 914 shift tube started to need repair/replacement in 1975?

DaveB