slow speedo reading, HELP!

[james280779]

Hello peeps, I am in need of some technical advice regarding the speedo reading on my 1972 Avenger. I have replaced the original 1500cc engine and auto-box with a Vauxhall 2litre 8v. unit and 5 speed box. It is now all up and running, but one of the few remaining niggles is that the speedo reading is now well out,ie: reading far too slow . I would prefer to use my original speedo, but if necessary I will go with something else, so if anybody has any suggestions I would very much appreciate your input, many thanks, Steve.

[miniman]

I suspect the speedo is driven from the transmission which now has a different final drive ratio so it is under-reading.

Speedy Cables will recalibrate the speedo for you: www.speedycables.com

[Motown Junk]

http://www.speedycables.com/

Not used them myself, but may be able to help.

[Motown Junk]

tsk - too slow - damn my pudgy fingers

[james280779]

many thanks guys, I`ll contact them, regards,Steve.

[DickyC]

Or do what everyone else does. Follow a mate with a newish car and a decent speedo at set speeds and stick teeny bits of the peel off bit from a car park ticket on the speedo at the appropriate points. Possibly with biro marks on the stickies for added accuracy.

No? Not everyone else? Just me, then.

[oldoiler]

miniman said:

I suspect the speedo is driven from the transmission which now has a different final drive ratio so it is under-reading.

Speedy Cables will recalibrate the speedo for you: www.speedycables.com

They will need the tyre circumferance and how many turns the speedo cable revolves to complete one tyre revolution - if my grey cells are correct, this allows them to adjust the speedo head metal disc/magnet gap to give the correct MPH.