So I have developed a terrible new noise. I mean it sounds horrific. I installed a new spec stage 3 clutch, fidanza billet aluminum flywheel, and RAM slave. I used the throwout bearing that spec sent as it looked beefier and of better quality than the one with the slave. All was fine through the break-in period. 500 miles of violently engaging but quiet clutch assembly. During the last day of break-in I started hearing this noise when leaving a stand still. It sounds like a metallic binding or twisting noise.

It does not happen if I let the clutch out really slow and take it really easy getting started. It does not happen if I smash the gas, though I spin tires in 1st and 2nd. And it does not happen if I slam through gears while drag racing. It only happens when engaging the clutch from a stand still under normal or more load. The clutch holds power (H/C car) and does not seem to slip. I have no strange feelings in the clutch or anything, so this leads me to believe it is not the clutch. I have removed the bellhousing inspection cover and all seems well in there. I have removed and retorqued my exhaust manifolds and the h-pipe. (It really sounds like the exhaust is binding right under the center console). I have even removed the 2 bolts connecting the front of the h-pipe to the bellhousing to see if the noise changed, but I didn't notice a difference.

I really dont want to have to tear the car apart AGAIN. (The car has seen more time in pieces than together in the past couple months) I am hoping that someone says, "HEY! I had that exact same problem and this is what it was!" Wouldn't that be nice... Any ideas folks?

I really wish I could post a video but I don't own a video camera and I don't know how to get video from my phone to this forum. I know it is hard to imagine a sound that someone tells you about. My girlfriend says it sounds like a car horn But I think it sounds like air brakes on a semi.

 

I assume since you had the driveline apart, that you inspected the torque tube and replaced the pilot bearing.

 

I didn't replace the pilot bearing because I couldnt get it out. I tried using a puller and everything. Even a few old school tricks for stubborn pilots. So I gave up and left it, rather than potentially doing damage. And as for the torque tube, I found out about the crappy rubber bushings AFTER I did the install so I have been leaning towards checking the front one. I didn't know there was anything specific to check when I was doing the job. This is my first vette, I am used to driveshafts with U-joints.

 

Well, that certainly leaves some unanswered questions. Unfortunately, there is only one way to know for sure. Pick up a service manual for next time.....salvation lies within.

 

HAHAHA, I know, I know. I asked around on the forum for a little while about the clutch job and I used a couple different write ups. Thought, I was well prepared. Guess not. Anyone else have any ideas before I tear this all down again?

 

man im goin thru the same problem right now, i had just installed new clutch, slave and pilot and i did not think anything of the input shaft moving when i was doing the swap, which has led me back to taking apart again... looks like bushings were the cause for failure of the slave and the pilot, just my guess. but mine made the same noise for a while then died on me, hopefully you can take it apart before this happens, if it is in fact the same issue.

hey look at it this way, u enjoy doin the work at least right? its a learning experience for me and i would rather do the work myself even if i could get it done for free

 

Did you by any chance use the old school method of packing the bearing with grease using hydraulic pressure to remove the bearing?

 

Doug,

I've never been able to get that technique to work, it's just frustrating as, well, you get the picture.

To the OP: Can't tell without hearing the sound, but the conditions under which you hear the noise is very similar to my '94 Z-28 when the clutch started chattering. Just a very loud, horrific, vibration-inducing noise. Treat it gingerly, no problem. Let it out aggressively, little or no problem. Clutch never slipped under full throttle load, say in 3rd gear (tires would slip in lower gears).

The only way I fixed the problem was to replace the clutch/PP and have the flywheel resurfaced.

Frankly, I hope I'm wrong, it would be a real bummer to replace that many parts and have them die within 500 miles. Could it be a break-in procedural error (don't know, since I'm not familiar with those specific parts).

HTH, and have a good one,
Mike

 

The reason I mentioned it is that there is a crankshaft oil gallery plug behind the pilot bearing that can be knocked loose. While this method sometime worked in my day it should never be used on LS1 engines.

 

Yes, I did try that method... but abandoned it quickly. Man, I hope this is not what is wrong. That would for sure mean new clutch disc. Although I would like to upgrade to the 3+ anyway. Wouldn't oil contamination cause slippage though???

Well, looks like I will have to take it all apart...... dsipos05, yes I do enjoy doing my own work, but I just did clutch, then heads and cam a week later, then had to take it all back apart to replace my crank pulley bolt a few days after the H/C. In the past 2 months I think my car has been off the road more than on and it's my DD. I don't get much time out of my day to work on it, so a one day job turn into a one week job.... UGH sorry for the rant....

 

Ouch! Didn't see that one coming......

 

If you knocked the welch plug out of the crank or damaged it using the grease methode you would know for sure as there would be lots of oil coming out of the bell housing

 

I think mine might be making the same noise, but I've had my textralia installed for almost a year now. Does it sound like metal to metal grinding? Maybe a worn clutch with the rivets hitting the flywheel?

 

It is the pilot bearing. Its the only time it will make that "errrrp" noise. Its the lateral play of the input shaft against the pilot/crank at two different speeds. The fact that you tried to remove it , made it worse as it was probably damaged.

 

My clutch sometimes makes a squeeling noise just as it is engaging. The clutch is a high performance one of unknown origin. It was in the car when I bought it and if I'm using it hard like drag racing or autocross it quiets down but never slips. It has done this for two years and hasn't gotten any worse. I've heard that some severe aftermarket clutches are noisy. To me if you had a pilot bearing problem it would make noise whenever the pedal is down because that is when the pilot bearing is turning.

 

i had alot of difficulty removing the pilot as well, after an hour of hammering that *@#$, i ended up ripping out the center of the pilot, so we stopped for the day came back the next and after about another 30 minutes of hammering, making sure that the bearing was the only thing i was hitting, it finally came out. just got to really get a feel for the tool and expand the protruding hooks so that theyre tightly squeezed around the other side of the bearing.

man i totally understand ur frustration, my vette's my dd too and ive been driving my wife's ford... oh no!!!!!!!!!!! i cant believe i said it... hopefully my treason wont last long

 

WRONG The pilot bearing is turning whenever the engine is running. It is pressed into the crankshaft; and the input shaft runs in it.

 

I'm glad you brought this up. Could you please explain this in more detail, I think more of us would like to understand better....

 

What he means is that the pilot bear is "turning" relative to the input shaft. When the clutch is engaged there is no relative movement between the crankshaft and the input shaft (both are rotating at the same speed). When you depress the clutch that rotational relation disconnects and the input shaft starts "spinning" within the pilot bearing/bushing.

HTH, and have a good one,
Mike

 

It sounds like you have seen this before... is that true? "errrrp" is an excellent interpretation. If you have dealt with this before and it is more than just a guess, I will plan to do it tomorrow.

And no, I have no oil leaks from the bellhousing. I don't think I damaged the plug as I didn't really have much room to swing a hammer to compress the grease anyway. The pilot bearing puller I was using broke 4 or 5 times while trying to remove the bearing. I kept welding it back together but finally just gave up and put the car back together.....