Triumph Repair: speedometer cable relacement, speedometer, cable

Question
QUESTION: I want to relpace the speedo cable on my 1979 Spitfire. My book states I can remove the old one from the transmission from under the car. I looked at it and it seems like there's not much room. So, can it be done this way? Any helpful hints?

thanks, jan

ANSWER: Jan,

Easiest way to work on anything transmission related is to pull the trans tunnel cover and do the work from within the car.

It's not necessarily a fun job as you'll need to pull out at least one seat (I prefer pulling the passenger side seat) and the dash support, then pull the carpeting and trans cover.

Once you've pulled the cover replacing the cable is a piece of cake.  While you're there it's not a bad idea to check the trans oil and maybe even bleed the clutch hydraulics.

And don't forget to seal the transcover to the bodywork, it'll prevent engine/exhaust fumes and heat from coming up under the dash.  Yes, it's a convertible, so you can't totally escape Eau de Castrol.

Cheers,

Jim

---------- FOLLOW-UP ----------

QUESTION:    Now the speedometer works, but both odometers don't. I'm thinking this is something I can't fix under my shade tree?

   I don't know if this can be a follow-up question or not. My car is a 1979  Spitfire1500. It has an electronic distributor. It has a vacuum advance thing on it, but no vacuum hose attached. Is this right? I also have a single Weber downdraft carb if that makes any difference.

Thanks, jan

Answer
Jan,

What's possible is that the speedometer cable isn't pushed all the way up into the speedometer.  Sometimes it's a loose connector, sometimes it's just poor workmanship on the cable itself.

One thing to try is to:

a)  make sure the cable end is tight onto the speedometer
b)  remove the transmission end of the cable and gently push on the inner cable while twisting slowly
c) put the transmission end back on and go for a drive.

If that fixes the problem permanently, great.  

If it works for a while then fails, it's possible to shim the inner cable by inserting something (I used a cut finish nail) into the plastic drive gear.  Keep in mind that if you put too much pressure on the speedometer it is possible to cause damage, so it'd take some trial and error.

It's also possible that the odometer has packed it in.  After all, it is 29 years old.


Cheers,

Jim