5-Speed Noise

[AZmike]

This problem started today at 191xxx miles. When the clutch is engaged and I'm coasting in 5th gear I sometimes get an unusually loud whine. It's only in 5th gear and only when using the engine to slow the car. First gear also seems to move the shift lever more than I'm used to, but it might just be that I'm paying more attention now. My guess was that one of the ball bearings in the transmission is about to go (or already has). Is anyone else familiar with this problem?

Thanks

EDIT: I just checked the transmission oil--it's full.

[Xulfiqar]

This only happens when you have really thrashed your trans with little or incorrect oil. Coz the 5th gear cog is at the last of the countershaft fed by a small amount of oil through a tiny hole. If the oil is low or too thick the pinion does not get full lubrication.

What kind of oil are you running in the transmission. You may try running an SF grade 15W40 oil caltex delo 400 (diesel)

[AZmike]

Ok, I fixed it. When I removed the transmission end cover I found that the countershaft nut had come most of the way off. The noise I heard was the nut rubbing against the inside of the end cover. This produced a lot of play in first gear and kept me from shifting into fifth (only would grind). All the splines were still fine but since the countershaft fifth gear had cut up the shift fork somewhat I went ahead an put on some spare parts I picked up at the yard.