I've been having this noise for a few months now. Just seemed to start one day, but it may have been gradually making it until it got loud enough for me to notice. Bill and I have looked at it, and it seems to be definitely coming from my clutch in some way. It sounds like a bad bearing. It's just a steady "tsstsststss" (that's the best way I can describe it), like a bad bearing that keeps turning. We thought for sure it was the throw out bearing, so I brought it to Bill's shop last night and we pulled the tranny and replaced the TO bearing with a known good one that came from Bill's ECSB truck. Put everything back together, and to my disappointment, the noise was still there when I started it back up. It is definitely clutch related, because it only makes the noise when the clutch is DISengaged....when the clutch pedal is out. The noise abruptly stops when the clutch is pushed in, and abruptly starts when the clutch is let out (in any gear and in neutral). This is a valeo style clutch, PP, and solid flywheel that we got out of the parts truck that I originally used for my e40d to zf5 swap, so we have no ideal how many miles it has on it.

Hopefully this describes it well. Any ideas or personal experience with this? Would a bad pilot bearing cause this? Maybe a bearing in the transmission? Or could it be something in the pressure plate or clutch disk itself? I'm afraid the only way to know if it is in the clutch or not is to replace the clutch, which would not be ideal for me right now.

 

Sit in the truck w it running and in neutral. Take the shifter without touching the clutch pedal and gently move it into gear(obviously it won't go so don't force it). If the sound goes away when you're doing that it's a high chance that it's the springs in the clutch disc getting ready to give up their places in the system.

 

I'll have to try that this evening. What would that do to cause the sound to stop though?

 

As it was explained to me -

Trying to engage a gear while the PP is not released will start putting pressure against the clutch disc because of the spinning motor. Since you can't actually get it in gear(and shouldn't really be trying) the truck won't try to move but the tension in there now will be enough to pull enough slack to stop the rattle.

My old LUK clutch started doing that and I asked the trans guy I used to use. He had me do that process and the sound stopped and he immediately said it was the springs in the disc. I swapped the clutch out a few weeks later and sure enough those things were damn near about to fall out.

 

Interesting. I'll try that tonight.

 

You might want to look at the input shaft bearing on the tranny. It spins all the time the clutch is ingauged. I have never had one go bad in a ZF, but had 2 go bad in a T18 transmission in an 86 gasser.

 

No, it makes the noise when the clutch is engaged. The clutch is disengaged when you push the pedal in

It's either the clutch or the input shaft bearing. When you try what Jacob suggested let me know what it does.

 

What's the word Tyler?

 

I don't know if he tried it or not Jacob. I talked to him a few hours ago and he hadn't mentioned it. He will be here in the morning, we'll try it then.

 

...Whatever... I should have said when the clutch pedal is disengaged. There, happy now?

Tried it, no difference. Tried in a few different gears, and it made absolutely no difference. I still don't see what that would affect on the clutch disk, but it was worth a try.

 

This is a very odd noise..hmm my e4od never has done that lol

but seriously. if your foot is off the pedal my thinking is its internal trans.the input is spinning and countershaft.the clutch eliminates pilot brg when foot off pedal if noise goes away...eesh...my head is spinning now.going back to work..stupid fork trucks

 

No joke right. At least it's not a dodge. You'd never have engine problems but you would know what's going on because you'd have dealt with it 18 times by now.

How much clutch pedal do you have to give it to make the sound stop?

 

This maybe out in left field, but I know when we had the clutches out of the heavy off road equipment, that sound was similar to the sound made when a clutch friction puck was coming loose or a rivet/bolt had worked its way loose and the "puck" was rubbing where it wasn't supposed to. It just needed to be replaced, and it quieted down. Like I said, it maybe a long shot. My 2 cents....

 

I have a dodge also

 

If you had the trans down, why didn't you look at the clutch