455HOGT37

Did a search and could not find "my" issue, so I'm apealing to the Collective...

2008 base coupe I bought new, and in the nearly 10 awesome years I've driven this thing this is my first "WTF was that?" moment.

110,000 mile freeway flier, original clutch which still seems to have plenty of life left. At 30k, the trans and tube were dropped for a warranty repair of the engine rear main leak. Other than that and a MGW shifter thats been there since almost day one (still perfect, btw), the car is as it left the factory.

Noticed the issue this morning backing out of the garage (cold trans). I have a slight bearing growl sound right at clutch engagement. I did some driveway troubleshooting and quickly realized that it seems to be related to input shaft rotation. In neutral and clutch engaged, I'll rev the engine to 2k, disengage the clutch and drop to idle. As the input shaft spins down it will "rattle" briefly just before it stops spinning. The noise is coming from my feet and only when the input shaft is free and spinning down. If I had to guess, I'd say it was the front bearing on the torque tube... But I have not been in one of these yet.

So in summary, no noise when driving, or when the clutch is engaged, and minimal/zero noise when warm.

I am fully prepared for a drivetrain drop, and will certainly replace the clutch, but does anyone have any wisdom for the actual source of the noise? Need to start ordering parts - would like to have them all in hand.

Many thanks!

Dutch08

FWIW ... my '05 49K does much the same thing (I think). If drive the car daily I don't hear it, but in cold weather I hear it. Usually quits after about 1/2 mile. I don't know if this is similar to yours, but just passing on information. I'm ignoring it for now.

455HOGT37

How long have you been ignoring it Dutch? I've resigned myself to the thought that its not leaving my garage until its fixed, but if its an issue that ca be deferred a bit then thats a bit of good news

Dutch08

I've been ignoring it about a year now. I haven't done anything about it (and don't plan to ), because it always goes away in about a mile or two. I figure (I hope) that it will become more noticable if something is about to fail.

Notes:

• This is an 05, 50K miles
• MGW shifter (maybe carries up more noise)
• Big Black Foam thing around shifter is removed (maybe carries up more noise)
• Using only the bottom shift close out, and not the top one (Yeah more noise maybe)

Keep in touch maybe we can help each other on this assuming its the same problem. I'm helping on a DIY new clutch on a '98 @ 100K right now, and I did notice the pilot bearing seems have a lot of wear. Do you think the noise could be that ?

455HOGT37

Noise source found-

Dropped the bottom out of the car and (almost) everything is perfect. Even the 111,000 mile clutch still has plenty of life left. That said, the input shaft pilot is eating itself alive. The bearing is a bit crunchy, but the shaft has substantial asymetric wear. Splines look great.

A little bit of research shows this input shaft to be about 650 bucks from GM, While the entire torque tube is ~ 1100.

Still exploring repair options, but I'd say if you hear this noise you are already in for an expensive repair.

Dutch08

I glad you found the problem, and a BIG THANKS for letting me know. That gives me something to go on for my noise.

455HOGT37

Well, the good news is that if you ignore it, its not likely to do much more damage for a while. The input shaft and pilot bearing are already toast; if it gets really bad you will wipe out the front torque tube bearing and maybe the front of the tube itself.

Thats not to say that you should ignore it - there is significant damage - but its unlikely you will have a catastrophic failure on the way to the shop.

Jfryjfry

Caveman74

Mine does the same thing. When cold it grinds really bad when the clutch is let out. It goes away when it gets warm. My car only has 60k on it. I was thinking maybe the throwout.