Triumph Repair: TR-6 Transmission Noise, british sports cars, shaft bearing


Question
QUESTION: My 74 TR-6 transmission makes a loud noise in any position when the clutch pedal is out, when the clutch pedal is  pushed in the noise stops. I think it maybe a bearing, but which one and is there an easy fix with out removing the transmission.  Thank you. Fred

ANSWER: Fred, "A noise" is useless information. What kind of noise? and does it make the noise when the clutch is out in neutral? Does it make the noise in every gear the same and at any speed? Does it make the noise on deceleration?

Howard

---------- FOLLOW-UP ----------

QUESTION: Howard, in response to your questions. The noise is like a growling sound and it makes the same sound if the transmission is in any gear and neutral, except when the clutch pedal is pushed in.  In fourth gear it doesn't seem as loud, but that be due to wind noise over taking it.
Thanks Fred

Answer
The noise then sounds to me to be either the laygear bearings, or the first motion shaft bearing.
It does not matter though. You have to remove the transmission to access any bearing in the gearbox.

"Wind noise over taking it"? that sounds like the transmission noise is slight then. If you are hearing this noise with the transmission tunnel cover off you should have a transmission man listen to it as that may be the normal sound a transmission makes before you remove the transmission to see what it is. Did you check the oil in the gearbox?

In the gearbox all the gears are rotating when the car is in neutral with the clutch out. The only thing that is not rotating is the mainshaft. All bearings except the rear main bearing and the tailshaft bearing are rotating. When in any gear all gears and all bearings are rotating. In 4th gear all gears are rotating but none are under load. The only bearing that is not rotating when in 4th gear only is the first motion to mainshaft bearing.

Many old British sports cars have noises coming from the gearbox and drive line that can be heard. You need to remember that in a British sports car you are sitting only inches beside the transmission and drive line. It is not like a domestic car that has the gearbox below a well insulated floor board. Before you take anything apart, you should find a local British car person to listen to it first as it may be the normal transmission sounds.

Howard