TRIUMPH 1500 VIBRATING NOISE
Q
I have a 1971 Triumph 1500 which has developed a strange and disturbing noise at certain revs. The noise is not there when driving around at 30mph, but starts to develop above this speed, reaching its maximum level at 50mph. Once you’ve gone past this speed, the noise decreases, and disappears if I reach 70mph. I do like to drive nearer the 50mph than the 70mph mark though, giving due deference to the car’s age. Another point that may be related is that the gearbox has a slight chatter on the overrun, though this is something it has had for a while and is not in itself so disturbing.
Graham Steer
AThe noise you describe does sound like one I have experienced before on both the 1300 and 1500 front wheel drive Triumphs. This is normally due to the clutch assembly, but can be for a number of different reasons – the clutch cover retaining bolts may have become slightly loose and are allowing the cover to move fractionally under certain revs, the clutch release bearing may be vibrating against the cover due to wear, or the clutch may have a broken pressure spring allowing the strange vibration. To check for any of the above conditions will require the clutch to be examined, but before doing this, one other point is to check that the air cleaner housing is not running too close and touching the offside inner wing. This is something I have also come across, and it can be due to corrosion allowing the engine to dip slightly.