Grinding noise from transmission

[mrmojo1111]

I have recently noticed an intermittent grinding noise from the transmission that only occurs when slowing to a stop with the gear selector in 1st gear and the clutch pedal depressed. If I shift into neutral, the noise will stop, and then will usually not resume when I shift back into first. The entire drivetrain is completely stock. Any thoughts as to what this might be? Remedies?

[LGAFF]

throwout bearing?

[mike100]

my old 95 made a whine with the gear in neutral and the clutch pedal 'out'. It quieted down pressed in (clutch released).

sounds like the bearing for the 1st gear cluster or main/driven shaft bearing is getting old.

[mrmojo1111]

28K miles, no drag racing to my knowledge. Assuming Black label as it was in the middle of the MY 1990 prod. run.

[scottfab]

These steps work on any manual trans in any vehicle not just the ZF6 and does not matter what oil or how you've abused the tranny.

1. At idle and clutch peddle pushed it do you hear the noise?
If you let the peddle up does the noise go away? If yes to both it's the throw out bearing as others have said.

2. If the grinding noise only happens when peddle is out and coming to a stop but only in 1st but not in any other gear (no noise in 2nd) then try slowly coming to a stop in 2nd but start at a higher speed. If you do then hear it in 2nd doing this then I'd say the input shaft bearing is beginning to fail. If doing both of these "slow down" testes create the noise but not every time I'd say you have something (grit) floating in there. But unless you've done some maintenance on the tranny lately that's unlikely. On my first ZF6 rebuild I did have a bit of dirt that was left in and I had a grinding noise upon deceleration like you describe. It went away after I flushed the ZF6 and refilled with fresh oil.

Have you checked your oil level?

[GOLDCYLON]

throwout bearing?

Or low on oil both possibilities