Slap on the dashboard gets the rev counter working

Whenever I go over bumpy roads, of which we have many in Johannesburg suburbs, my rev counter drops to zero or falls to the other side.



When this happens, I have to slap the dashboard, and the needle returns to the correct position.



My mechanic has cleaned the contacts, but suggests I should just get a new unit.



I can't afford to try and buy different parts as shipping from the UK will be too pricey.



Please let me know your opinion, including what part (number) I should get.

from the last news http://ift.tt/1EgppvU

via IFTTT