Speedometer Cable Drive MOD

[V Mad]

Does anyone have experience of problems with the cable drive at the gearbox. I have a Mk1 MOD with A-type OD which has a right angle drive adapter at the gearbox. It is not easy to access so I am looking for some clues before having a go.

Cable is good and new and I can feel from the speedo end that it locks into place when pushed down and so will not turn when stationary, but neither does it turn when wheels are moving.

Any ideas?

[new to this]

chris

there is green worm gear in the gear box that wears,the cable also wears at the ends,

[V Mad]

OK Dave. The cable is brand new so it must be the worm gear. Can we get replacements for the A-type and can I replace it without pulling out the box?

[V Mad]

If its the worm gear, Rimmers shows two speedo drive pinions: 154015 x 15 teeth is the only one now available and is on offer at £2.40. But why would they list two types?

[Firept]

Chris.
Have you tried a new 90deg drive?
I had problems with mine. when I was rebuilding the Gbox I knew there was a problem with the speedo take off I had already replaced the speedo cable so I knew it was not that, rebuilt the speedo so it was not that only leaves the 90deg or the gear in the o/d. So I thoroughly cleaned out the 90deg drive washed it air dried it never took it completely apart and then re-lubed it but it still played up bought another from Peter and all was fine.
The different gear colours define the ratios for the speedo calibration, may be worth a look at some of the MG ones as I assume any type A o/d will have the same take off arrangement.

Paul.

[71Stag]

Mine chewed it's drive pinion a couple of years ago you can get to it (Just) I dropped the rear mounting down and disconnected the Prop shaft to do it and even then it wasn't much fun.
Best of Luck
Bruce

[new to this]

If its the worm gear, Rimmers shows two speedo drive pinions: 154015 x 15 teeth is the only one now available and is on offer at £2.40. But why would they list two types?

chris

you can replace the worm gear without taking the gear box out,but check the angle drive first,also check the speedo its self

dave

[V Mad]

Speedo is fine, so is cable. That leaves two suspects, the drive gear and the right angle drive. I think the drive gear is plastic so is the most likely to break and is only about £2.40. R/A drive is £36.00. I think I will buy a drive gear but not a R/A drive, then have a go at the repair.
Cheers