MG Car Repair: rev counter fault on 1955 TF1500, reduction gearbox, rev counter

Question
hi just had rebuild but rev counter keeps flicking had new coil and electronic ingnition the car is atf 55 1500 can you advise please

Answer
Hi Barry
The 1955 TF1500 has a mechanical rev counter.  It is driven off the back of the dynamo, via a reduction gearbox.  A wavering needle can be caused by:

o Lack of oil (EP90) in the reduction gearbox
o Gearbox faulty or loose where it attaches to the back of the dynamo
o A loose fanbelt
o A sticking cable
o A faulty rev counter.