throttle cable replacement

[ched]

Can you pull in a new cable with the old one if the old one is not yet broken?

[Ol'fogasaurus]

Ched, if you have an air supply (compressor and hose with a nozzle) you can knot the end of some string then introduce it into one end tunnel then using the air source blow the string down the tunnel. When the string shows up at the end give yourself some extra then cut and tie the other end to the cable then pull the cable down the tunnel.

Tying the cables together can cause the tie area to be too thick for the tunnel because of the knotting of what you are using to join the wires.

You could possibly tie the string to the old cable and pull it through also but I haven't tried that way before.

Lee

[ched]

Thanks for the reply the last suggestion of tying a string to the old cable ( using the old cable to pull the string through) and then using the string to pull the new cable through seems like a good idea. And yes I do have a compressor as an option also

[SCOTTRODS]

Honestly, if we're talking about an unadulterated VW beetle... pull the old one out.... slide the new one in... Easy job for the most part. On occasioin the throttle cable tube in the engine tin may move and cause misalignment, but even that isn't much trouble to get past. In my daily job we pull long runs of Heat trace wiring and connect the old to the new using a crimp connector, and it goes through the opening pretty well... but I suspect the cable we're pulling is more difficult to run, where the beetle throttel cables are much nicer to work with due to their length.

[ched]

Actually it’s a 1974 Ghia. The cable is original and was thinking it might be a good idea to replace it “preventively”

[Ol'fogasaurus]

Back in the old day (we're talking about the late 50's now) there were a lot of vehicles and other things that had cables run though different types of tubes/housings, some with ribs allowing bends because the tubes were coming out off the firewall to under the body (they had a real frame), not straight like the gas pedal line on a VW, and this was the way I was taught back then. Feeding lines, especially old ones through the tube by hand can work or can be a pain in the Poo-poo.

Lee

[Max Welton]

FWIW, I use 1/16" "wire rope" available cheap at the local farm supply store to make throttle cables. It's quite flexible but I've never had any issue pushing it through the tube.

1791264.jpg

Max

[Ol'fogasaurus]

Max, based on the pix only I think your loop needs to be smaller and/or your fastener needs a bigger or different style of head or the addition of a washer. That loop looks like it could drop off the fastener easily which could be bad if it does at the wrong time.

I wonder if the "shank" could be drilled so the "wire rope" could be threaded through it but that brings up other potential problems. I did a search to see if anything like this was available but I only found the threads drilled or the head drilled for locking devices; the stock style of VW cable runs from ~5$ and up. Stock is a simple "Z" shaped slide through a hole like your bolt does in this connection.

Lee

[Max Welton]

A more useful view. Never an issue with it slipping off.

1791263.jpg

If I remember correctly the cable cost 9 cents/foot some years back ... in pretty much any length up to 50'.

I ran this setup for several years without issue. I actually made up a kit (extra ferrules, crimper/cutter, 25' of cable) that came in handy on long cruises for other people's cars. Never had to use it on mine.

Max

[Ol'fogasaurus]

Max, usually, when there is a wear potential like you have here even when it is so small, there would be an inside liner to protect the wire strands from wear. Not saying it is a really bad way of doing it just something that when I was working (checking others work and designs in this case) I would be concerned about it (design wise) enough to check with an engineer and/or a specialist engineer as that was my job for many years, but I was also working in aircraft where the rules were very strict too.

Anyway, in this pix it looks better than in the first one I saw.

Lee

[Max Welton]

The bolt and bushing could have been made longer, allowing for a straighter shot for the cable. There's room for that. And if I'd had a problem with it slipping off that is exactly what I would have done. It may help that I favor a pretty light return spring.

But the failure would present as nothing more than the throttle dropping to idle, just like the common broken cable syndrome. So this is certainly something I'm comfortable using my own design for. It isn't an airplane and it isn't the brakes.

The car was my full-year daily driver from 2007 to 2016. No problems with the throttle.

Anyways, my post had to do with the cable and the lack of difficulty it presented feeding it into the tube. A stiffer piano-wire throttle is even easier.

Max

[Ol'fogasaurus]

Wasn't picking just stating what I have seen before especially when cable stretch is involved which they do.

As I said, I don't ever remember doing or seeing anything like that on an airplane but I have seen it done on cars and trucks before so I just kissed the subject. Just something to think about and that was about it.

Lee