Hey guys, I have a 90 with the ZF 6 speed and for some reason it sounds like a can full of bolts being shaken while I am driving in the lower rpm's in 5th and 6th. When my friend was in the car with me he grabbed the shifter and it quieted it down a good amount. I need to figure out what is making the noise. I haven't really noticed it in the lower gears, but I only drove it a few days before putting it away for the winter. Any suggestions or things to check? I swapped my motor and rear over from another car so this was a project car. I have read that a lot of people do away with the dual mass flywheel and that there would be noise from that swap. This has an aluminum flywheel that isn't a dual mass system. I forgot that I had some lugnuts in the center console so that will be the first thing that I try, but it was pretty loud. This happens between 1,500-2,500 rpm's roughly. I'm just hoping it won't need a rebuild. Oh the trans also has a hurst short throw on it. Any ideas?

 

Probably you're single mass flywheel. Contact the ZF doctor.

http://www.zfdoc.com

 

The quieting when you grab the shifter makes me wonder about a loose C-beam bolt. Or even a worn tailshaft. Don't know how to check the later. Jack it up to check the C-beam.

SMF may cause this but a problem with one of the two above may exaggerate it.

Bill @ ZFDoc is the expert.

 

on my 90 the ashtray/drink holder door would rattle, but I think this maybe worse.

The single mass, if it is your issue, will rattle the worst with the clutch out at idle, and when you accel with a load.

you can try going in 5th or 6th up a hill. dont give it gas till you hit the hill. if you hear the growl it will be the single mass. I drove an LT4 with an aluminum flywheel and it would growl with a load on it.

If the C beam is loose... I could nail the throttle and watch the shifter come up about a 1/4 inch. could feel it in my hand as well.

I have not got around to putting my hurst in so I dont know if that holds any clues.

 

You know I wonder if my friend was resting his hand on the console when he was holding the shifter. That could make sense. I will have to wait and see as soon as the snow melts. Thanks for the ideas guys, keep them coming!
Brian

 

what kind of clutch do you have in there?

Is it an aftermarket sprung-hub clutch? Sprung hub will reduce noise vs. non-sprung hub on an SMF. Ive heard that non-sprung hub w. a SMF can be quite a racket. The stock clutch is a non-sprung hub disc.

Im very happily running the lightweight Fidanza flywheel combined with a SPEC stage III+ sprung hub clutch disc.

Someone mentioned lugging up a hill, yes, thats when I get the rattle noise. Its a reminder that I should prob to downshift. I personally enjoy the slight noise that is present under some circumstances. Adds to the thrill of it all.

A loose c-beam bolt will cause the shifter to rise and fall, not cause gear noise (I guess maybe it could if it was really loose). I learned this the hard way when I reinstalled the c-beam. The torque specs in the chiltons guide were not high enough for what I needed to torque that thing to. Im now using beam plates and those helped a bit.

Look for loose change in your console, and other sources of the rattle. I used to have an insane rattle that happened under full throttle. To me, it sounded like transmission noise. It took me a year to find it and it ended up being the ring pin on my fire extinguisher which is bolted to my roll cage (bolted to the harness bar part right between the LF and RF seat).

 

I installed a Mcleod street twin clutch into a customers LT4 C4, and after that the trans sounds like its got rocks rattling around when in neutral with the clutch out. And when accelerating through the gears it was also very noisey. I think your noise issue is due to the single mass flywheel. Unless it was all quiet before then one day the noise starts up, that would tell me that something else happened in the transmission.

 

in that boat myself

 

That is the problem though, I bought all this stuff used and out of the car. I'm not sure if it has done this since day one or not. I don't know what clutch it is, but it is a 6 puck clutch. It doesn't really make a lot of noise when in neutral. The only spot I where it is really noticeable is in 5th and 6th. I also need to get the car aligned and new tires on the back. I guess it could be a lot of things. I just need to wait for the weather to be nice enough that I can take it for a drive and try some things out. I'm hoping that it is the center console. If I can't figure it out then maybe I can take a quick video and post it so people can see what it is doing.