Which Speedo Required?

[jmcar]

I have a '68 Traveller with the original 4:22 diff and wheels but a 5 speed ford gearbox conversion. - Any idea which is the correct/closest speedo out there to get? My current one has given up after much needle bouncing around! I have checked the run of the cable and that is fine so I'm guessing it's either the speedo drive gear in the gearbox causing problems or more likely the speedo head is so woefully wrong for this gearing setup that it couldn't cope with the tpm?

Any ideas would be useful as the Ford 5 speed is a fairly standard conversion.

I'll check later what the serial/tpm is on my dead speedo.

[Sidney'61]

I have a ford gearbox and 4.22 diff too, I used the original speedo for a while until it died, it was only about 5mph out across the range, now I'm using a speedo from a mini which is almost completely accurate, i cant remember the tpm (possibly 1348) but I'll check in the morning.

[jmcar]

Thanks,

That is a huge help - if you could take a piccie of the speedo face with all the numbers on and post here or just post the numbers themselves I can search one out for myself. Out of interest why did the original die? Was it like mine that it couldn't seem to handle the uprated setup?

[Sidney'61]

The numbers don't come out in the photo, its:
SN 4417 / 00
TPM 1376

Im not sure what model mini it's from as I bought it from an autojumble but it will be a later model as it has a black face.

I don't know why the original stopped working but I assume it had been working fine with that setup for quite a few years, the needle just jammed one day so it didnt give a reading at all.

[jmcar]

Hmm - after all this time, I have finally just replaced my speedo. To be more accurate, I have replaced the speedo drive gear, the cable and the head (new one is 1376 tpm). By my calculations, the correct tpm for my setup(ford 5 speed box etc) should be 1356 so i'm only something like 1.4% out which is fine for me.

The problem is the flipping needle is still bouncing around when driving along. If i'm cruising at 60mph the needle bounces between 55 and 65 for example.

I have checked the cable and it takes a pretty smooth run from the gearbox to the head. I've even removed the inner cable and made sure it has a small amount of lubrication all the way along before inserting it back in again.

I really am at the end of my tether with this - I've gone through 3 speedo heads, 2 drive gears and 3 cables but with no significant improvement.

Has anyone any more ideas as to what I can try? I am seriously thinking about trying to find some kind of electronic speedo setup if there is such a thing - maybe something off a motorbike!

[alex_holden]

A while ago somebody (Judge?) told me the cable supplied with his 5 speed conversion kit had an inner that was slightly too long. This puts an excessive force on the bearings inside the head and will quickly wear them out. Could that be a problem in your case?

[MarkyB]

Also the routing of the cable needs to be as smooth as possible, it is quite different to an electrical wire.
The symptoms you describe suggest the inner is catching and "winding up" until it overcomes whatever resistance it's finding.

[jmcar]

A while ago somebody (Judge?) told me the cable supplied with his 5 speed conversion kit had an inner that was slightly too long. This puts an excessive force on the bearings inside the head and will quickly wear them out. Could that be a problem in your case?

Interesting - not sure how i can check this although i may have an old inner somewhere i can shorten down. - I am on my third new cable!

Also the routing of the cable needs to be as smooth as possible, it is quite different to an electrical wire.
The symptoms you describe suggest the inner is catching and "winding up" until it overcomes whatever resistance it's finding.

I've routed the cable so that it follows the smoothest curves possible, so I'm not sure what more I can do in this respect - this is very frustrating