speedo

[rizzo]

Hi guys my 74 bedford has a speedo problem it jumps around and i have now idea what speed iam going has any one got any ideas thanks rizzo out

[Jeff]

I'd say about 85 tops.......

This can be a sign that the cable is frayed. It keeps sticking and letting go , giving a jumpy movement.

[LS120]

if it has a holden gearbox it could be the gears in it as mine did that until i put the right gear in the speedo cable end on the box. thers was a red/pink & greenish one & i used the greenish one  from memory as the pink one did the jumping around this on me..

[petrolhead]

First lets do the easy bit, undo the speedo cable from the speedo, now pull the core out and check for damage, if no damage wipe clean, apply wheel bearing grease and re install, if damaged take sample to Flexi Drive get a new one and install, if still bounces it'll be the gear

[rizzo]

Hi and thanks for the info iam pulling it to bits now rizzo out

[ben]

First lets do the easy bit, undo the speedo cable from the speedo, now pull the core out and check for damage, if no damage wipe clean, apply wheel bearing grease and re install, if damaged take sample to Flexi Drive get a new one and install, if still bounces it'll be the gear

spot on!!!! this makes a huge difference!

[Sweet Shock]

I changed my cable because of this problem and it has improved but it still moves a bit and I have a red one and my speedo is out a few ks so if anyone knows the correct colour one for a 253 trimatic  with 14 diammeter wheels let me no thankx

[cfjeff]

So far as I'm aware there are at least 5 different speedo cogs for holden gearboxes, I have a red, a green, a white and a yellow/orange one. And apparently there is a Gray one. The difference is the number of teeth on each which is what alters the speedo reading. Apparently you can get them from rare spares new.

Cheers Jeff

[ben]

what diff ratio pete? diff ratio makes a lot more difference to the speedo than wheels or motor

there is also adjustment on bedford speedos altho ive never tried using it.

[Sweet Shock]

I thing mines 2.75,