Transmission noise when clutch is out.

[alcyone]

Hey all:

I am having a "noise" issue that i would love some help diagnosing.

Car: 1994 awd 5mt wagon

Problem: When clutch pedal is pressed in, no noise. When clutch pedal is reliesed, there is a scraping/grinding noise. This noise occurs whether or not the car is in gear. It's gotten progressivly much worse over the past 300 miles.

I took it to a local garage, and the tech said it's probably an internal transmission problem and i should be looking into replacing the tranny. (This is after briefly listening to it) I thought I would ask you folks directly since you all know and love these cars so well.

Thanks so much in advance for any help!

Mike

[THAWA]

Is this before or after the input shaft bearing diagnosis? I would be guess it could be the throw out bearing or something like that.

[entirelyturbo]

Is the clutch adjusted properly? Maybe the throwout bearing is dragging on the pressure plate when the clutch is released.

[alcyone]

im asking this question after they gave the input shaft bearing diagnosos. im just trying to get other opinions before i shell out the money to have the trans replaced.

mike

[evolutionmovement]

Sounds like the bearing to me. That's what happened to mine at ~180k. It's cheaper and quicker to get a low mileage used unit than rebuild the old one.

Steve

[fishbone79]

I concur: this is a very common problem, I have seen it in 2 of my trannys. There are 2 carrier bearings on the mainshaft (input shaft). The blown one is the one in the middle, between 4th and 5th gear. You can drive it like that for as long as you like, it only increases the wear on the other gears, and eventually you will lose 4th (it is weird, you can shift into it, and its there, but the minute you put some pressure on it, its like a fish spitting the hook...gone!). There is a split-ring keeper on this bearing that serves to align the mainshaft relative to the lagshaft in the tranny; when the bearing is shot, it cannot align at all, and slips backwards. When you shift into 4th, it pushes the shaft backwards, and when you apply pressure, it kicks out.

To make a long ass story short, you should avoid 4th at all costs until you get it fixed (I'd rebuild it, at least replace that bearing and the synchros, another used tranny = another set of problems). 5th gear is not so hot either, but it can be jumped into from 3rd if absolutely necessary. Using 4th will make the problem exponentially worse, and cause more wear on the other gears.

Hope all that helps.

Cheers,

Morgan

[professor]

I'd drive it unless you can't stand it. A disentegrating bearing may go through several phases, some noisy, some not. So it may decide to shut up for another 10,000 miles.

My BMW has been losing its throw-out bearing for about three years, and I'll drive it 'til it breaks or clutch replacement , whichever comes first.

I'd also change out the lubricant, so as to remove any debris that it may have already spit.