Technical Another gearbox input shaft bearing diagnosis

[dumbledore]

Since I changed my clutch a few months ago I have developed some sort of drive problem. Vibrations that seems to have stabilised, i.e. not gettig worse, and now an increasingly noisy transmission. Initially I thought diff or driveshaft are going but now after considerable listening I am not sure if that is the case.

The noise I am getting seems to follow the engine speed, which means it cannot be diff or driveshaft. But the noise is still low pitch and is noisier under load both accelerating and decelerating. Putting the box in neutral and let the car cost the noise also disappears.

It all points now that I have the common fault of a worn out input shaft bearing. The only concern I have is that the noise is not there when car is stoped and engine running with clutch pedal depresses or not. I suspect that the noise will be there once the bearing wears out more.

Also since I changed the clutch I seem to have a gearbox oil leak too. Which is not that much as I refill the box to make sure it does not run out of oil.

My question is. Can I safelly assume that this is a input shaft bearing issue, and how long can I drive the car in this state before I fix the bearing?

 

[fingers99]

Also since I changed the clutch I seem to have a gearbox oil leak too. Which is not that much as I refill the box to make sure it does not run out of oil.

My question is. Can I safelly assume that this is a input shaft bearing issue, and how long can I drive the car in this state before I fix the bearing?

A leak will tend to conform the diagnosis in so far as a fubar bearing will kill the oil seal.

There has to be some risk of oil contamination to the clutch or a small leak turning into a bigger one pretty quickly.

So, the only real answer is to do the work as soon as practical.

 

[dumbledore]

Yes, I am planning to do this over christmas now.
Some more diagnossis is that the noise seem to be worse in low gears when I try to accelerate. The only gear that appears OK seem to be 5th, which is good as is the one I currently have to use most. So my assumption is the noise is actually a gear noise that is created by the movement in the input shaft as the bearing is not able to stop the shaft movement when the shaft is under some stress when I accelerate. I believe the 5th fear is located behind the rear input shaft bearing (one that is still OK, front bearing assumed bad) which is why the input shaft movement is better controlled causing less noise.