When my car is at idle with the tranny in neutral and the clutch out, I am hearing a whirring noise coming from the transmission. As soon as the clutch is pushed in it goes away. This makes me thing something is going on with the clutch release bearing. I did a search and found a few threads that pointed in this direction.

However, I just put a new ACT Street/Strip Clutch with HD Pressure plate in, replaced the pilot bearing and seal, new clutch release bearing and shift fork, and made sure to grease all points that the FSM points to with molybdenum grease, I also changed the fluid in the tranny while I was at it.

I have driven the car a few times since putting these in. I always warm the car up before driving it. I do so with the tranny in neutral with the clutch out and I have not noticed it before. Today was the first time I heard it. I had just gotten home, didn't notice any problems while driving, and was letting the car cool down when I heard it.

The clutch feels fine. It does engage rather quickly off the floor.

One of the threads pointed to a bad main bearing on the transmission. There was no noise before today. Could the main bearing have gone out that quickly?

Any ideas on what could be causing this?

Could the clutch pedal need some adjustment?

 

Well I pulled the transmission service plate today. Everything looks good. When the clutch is pushed in everything seems to be working fine. Here is a pic of the release bearing and the collar. Does everything look ok here?

 

When the clutch is depressed the noise goes away - this says that the noise is in the trans, and the input shaft bearing is (one of) the most likely culprit(s).

If it were the release bearing, it would likely be silent with the clutch engaged (no load on the release brg) and noisy when the clutch was disengaged (release brg loaded). Same thing for the pilot brg - when the clutch is engaged, the pilot brg just is along for the ride.

 

On my Rx-7 it is the complete opposite...

I´m so lucky that I know that it comes from the twin plate Ogura and it has to sound like that

the same sound here on this S2000

sorry. No additionional info for you here. I just had to pose around with my super parts
I´m ashamed about myself!

 

Damn, how the hell could the main input bearing go out so quickly? I didn't hear it at all, then all the sudden its a problem......

The noise in the video is pretty much what I am hearing, its only a lot quieter.

 

That right there usually means input shaft bearing. It's internal to the tranny.

I think your clutch is fine.

It's possible that the problem was the input shaft bearing all along. Mine has a bad input shaft bearing and it usually makes noise when the car is cold (and all the oil's drained from that bearing). Give it some time and monitor things.

Changing the main input shaft bearing does not require a full tranmission rebuild but it does require a somewhat specialized puller and you've got to drop the trans again to do it.

Dave

 

Is there anything I could have done to cause it to go out?

I have only put 70 miles on it since I got it back together.

I would think the input shaft wouldn't go in but, could it be the clutch disk not aligned properly? If this were the case could it be wearing the bearing in an odd fashion causing it to fail?

I made sure to bolt the bell housing up to the motor (flush) before putting the ppf on. I lined the ppf up to the diff and then to the tranny. I made sure that it sat flush on both the transmission and the rear diff. If these were not lined up properly could the input shaft be at an odd angle causing uneven bearing wear?

Could some dirt have gotten into the main bearing when I replaced the front tranny seal and scored it? If this did happen, why did it take 70 miles for it to go out? I did notice the oil between the bell housing and the main housing was very slimy and had metal particles in it. I did clean it all out before putting it back together.

I am running Red Line MTL 70-80. It is a slightly lighter oil than the FSM calls for, but it does not get very hot around here. Could this oil be to thin to properly cool the bearings?

Maybe I am just obsessing over a 14 year old bearing with 100k miles on it, but I gotta ask.

Does this just require removing the bell housing and pulling the bearing? Or is it a little more involved than that?

 

Case closed. This is solid evidence the bearing is shot. Metal particles from any other part of the transmission are not likely to migrate and collect here.

I would not run the MTL, it's too thin. The MT-90 is a better choice for this application.

Yep, but to pull the bearing you'll need a large 2-jaw puller with narrow hooks and a rig to keep it from popping apart off the snap ring.

I've got a perfect rig if you want to borrow it.

 

You know, I thought that looked kind of bad when I got in there. It does make perfect sense that it would be that bearing going out. The fluid that came out of the drain plugs looked nice and clean.


Sweetness, I will PM you when I get back in there.

Is this something that needs to be taken care of right away? There are only about 2 more months of decent driving weather here before the roads start icing over. When that happens she is getting parked until spring and much work will be done in that time.

I wanted to get some NEO 75-90 but there is not anyone around here that sells it and I really didn't feel like waiting to get some in. Plus I got the Redline for free so.... Free + right now is much better than paying and waiting. I will be changing that out over the winter.

In the last year is when I really started working on cars. I have always wanted to and only recently gotten the means to do so. So thanks for your help and putting up with my ignorant questions.

 

I've run on a noisy input shaft bearing for about 15k miles. Not that it's the best idea, since the metal particles in the transmission oil accelerate wear elsewhere, and it's caused a minor front seal leak to develop, but nothing catastrophic is likely to happen.

Dave

 

Changing to the thinner trans lube probably made it more audible - thicker lube tends to muffle trans noises in general.