Speedometer Erratic when braking -MR2 Turbo

[mattyboy44]

Hi

I have rev3 MR2 Turbo 1994, it has the mph clocks all changed but since I have had it I have noticed that the speedometer needle is erratic when braking going up quickly then back down like a surge of electricity has set it off. Sometimes when coming to full stop it can fly up to 100mph when I am doing like 5mph or completely stopped and back down again and then up and down a few times until it finally stops after a few seconds if that. This doesn't happen if I am not driving fir example if I start the car and put my foot on the brakes.

Anyone got any ides what might be causing this? Or can point me in the right direction please.
Thanks

[thomp1983]

Sounds like the nylon cogs on the gearbox sender are becoming worn

[mattyboy44]

Sounds like the nylon cogs on the gearbox sender are becoming worn

OK so can I replace or fix this? What do I need and where can I get it please?

[thomp1983]

If it's the sender then it'll be a case of sourcing a new or second hand one and swapping them, if it's the part in the gearbox ive no idea how easy it is to replace.

Start by inspecting what's already there