Experience Dealership line mechanic on MG, Triumph, Jaguar for 15 years, Instructor in commercial mechanics school 2 yr. Product information manager for piston and valve manufacture, Instructor & hotline answer man for import car parts importer 15 yrs.
Organizations Associate member SAE
EAA member
Publications Import Car magazine
Education/Credentials ASE Master Auto with L-1 certification up to 2000
Question My 1972 spitfire 1300 has recently and suddenly started vibrating a great deal at the rear end. The vibration builds from around 40mph to 50, I daren't go faster, everything is shaking. Visual check everything appears ok, the diff does leak but was recently topped up. On stands everything seems to move freely enough. Recent work - 200miles ago new gearbox rear mount bushes. On the 200mile trip during which this started, it was intermittent lasting for about 20mins each time, stopping 1st of its own accord and again when I stopped for petrol.
Any ideas? thanks, Marcus
Answer Hi Marcus,
A vibration in the rear can be any of a dozen things so you need to put the car either on stands or on a lift and run the speed up to 40+ MPH and look to see if you can see what is vibrating. A wheel, either axle or the driveshaft??? This car has "U" joints on the driveshaft and one on each axle. You should check to see if the front flange of the differential has any play up and down or any movement in either side flanges out from the differential. Look for signs of rust at any "U" joint. Check for any free play in the outer wheel bearings. It is not likely a tire problem as you said this can come and go and a bad tire is always bad.
Let me know,
Howard
