The Triumph Dolomite Club - Discussion Forum

Hello all

My Sprint makes a rattle / knocking noise when pulling away from standstill. It appears to be something coming from under the floor in the transmission tunnel area, just at the rear of the front seats. It sounds like it could be the prop centre bearing at fault but the car has recently had a new bearing and prop shaft, so I hope not! I’ve also fitted a Volvo gearbox mount and I am pretty sure all is well there.

I need to get under there and have a look to see what’s going on of course, but wondered if there is something other than the centre bearing and gearbox mounts that I should be looking at. Also, I know that if the centre bearing is fitted with the bolts both going in the same direction then it can cause vibration, but would it be possible that that could cause the prop to rattle around like that?

All the best, Bish.

If it's an actual rattle and thump, i'd be inclined to suspect the 2 little tag brackets that support the centre bearing loose against the body, rather than something insulated with rubber. one of them is only secured by a single stud through the floor and can be a PITA to get tight without having all the seats and carpets out!

The (manual trans) Sprint has this peculiar method of fitting the centre bearing ears, one above and one below the little support brackets. There is a valid reason for this, fit both above (with bolts from below) and the prop CAN run too close to perfectly inline for comfort. The prop needs to be a couple of degrees at least out of perfect alignment to avoid resonances, vibes and premature front UJ wear. But having it perfectly in line wont make it rattle, something has to be loose for that! And any problems from TOO perfect alignment take time to show themselves.But because it's 70s BL car, production tolerances vary so much that the angle CAN be good even if it's been fitted incorrectly! Especially if you have the Volvo mount which changes the tailshaft height very slightly. You have to measure somehow to be sure!

Steve

PS, the only other thing I can think of involves a poorly fitting Rimmers sports exhaust, another can of worms altogether!

Axle tramp caused by deteriorated bushes in trailing arms and/or radius rods?