My '92 has developed the rattle that says, "flywheel needs help." Since the original LuK part is long since n/l/a- what are others doing? Changing to a conventional wheel is, of course, not first choice. Is there a reliable rebuild service for these wheels?

 

I looked and could not find a company that was still doing it. Every now and then you can find a lie mileage one on eBay.

 

Thanks- I've cruised online as well, no luck either. Funny thing is- due to the first owner's ignoring the poor clutch function (due to bad slave cyl), I had to do a trans rebuild in '04 when I bought it, with 60k miles. At that time, the clutch and wheel were plenty good. Five years ago, with 97k on the clock, we replaced the clutch and wheel. Now the car has 100k and I'm getting a sporadic and irregular noise like tapping on the bellhousing with a small hammer or suchlike, as well as a substantial trans rattle when killing the engine. If the flywheel is in fact failing, that would be just 3k miles!

 

Given all that you've said about this so far, I'd wait for a solid diagnosis before searching for a DMF. With only 3K miles on the one that's in there, it seems as though the odds would tilt strongly toward something else being wrong.

Live well,

SJW

 

My thoughts exactly. By scouting for a replacement I am trying to cover all the bases. Of course, it's tough to diagnose a noise without hearing it, but for those reading this thread I can say that, as the noise increases in frequency and volume, the wheel sounds more and more like the source. Especially telling is the loud rattle from the area of the bell when the engine is shut down.

At this point, I'm trying to disprove this diagnosis by coming up with an alternate one.

 

Suggest the guru for our transmissions and clutches:E-mail billb@zfdoc.com or call Bill Boudreau at (602) 319-6575

 

Thanks for posting- yes, I know Bill and we have an email thread going. He is truly an asset for these now-old cars.

 

Bill is one of the truly great people who can help with these issues.

Given that there have been so few miles logged since the last clutch and flywheel were installed, I can't help wondering of the flywheel bolts have come loose, or some such. A new DMF should have never failed so quickly.

I'd disassemble and inspect, then take it from there as required.

Good luck with it. Let us know what you find.

Live well,

SJW

 

Actually, I'm going to take it a little further before disassembly- tomorrow I plan to make an audio file of the noise and send it to several experts, Bill included. Haven't done it yet because my past experience is with Win7 which we abandoned last year in favor of Linux Mint (btw- still can't get used to how much better Mint is over MS!). This will be the first time recording with Mint using a mic.

I agree with your strategy, only wrinkle is that if parts are needed the shop will have to leave the car outside and vulnerable to trophy hunters and vandals.

 

That adds a new wrinkle to the picture. I'd gotten the (mistaken) impression you were doing the work yourself. I can now see why you'd be checking out the available options.

I'm still highly skeptical that what was a brand new DMF would have failed after only 3K miles. Curious to hear what they find when they disassemble.

Does it behave any differently with the clutch disengaged, either while running, idling, or during shut-down?

And, has anybody stethoscoped it to isolate the general location of the noise?

Live well,

SJW

 

I''d think that a physical inspection just removing the flywheel cover would be the first move. The audio file thing I can't say I'm particularly fond of. SJW's suggestion of 'stethoscope' certainly sounds like a very good idea!!

I'd think the first response of anyone who you send the audio to is going to be > remove flywheel cover and check this!!!

 

just out of curisoity,.... would a luk DMF/clutch set up be worth in a good used condition? i just took mine off and was thinking of going to a single type flywheel and clutch. it says LUK stamped right on it

 

Actually my history is 95% hands-on, repairing my cars as well as the trucks and heavy equipment that were integral to my business when I was still working - my garage has a lift and a fairly complete set of tools and electronics. As with other vehicles past and present, I have a (well-used) Factory Service Manual. But this is not a 1-person undertaking, and I'm no spring chicken. In recent years I have been the "assistant" to my long-time friend and Chevy mechanic when the Corvette was in his shop.

Really not necessary to scope this one, as the sound's source is no mystery. I, too, am finding it hard to imagine that the wheel has failed. The noise is at idle only and is the same with the clutch in or out, which narrows down the source. On shutdown, there is an unmistakable rattle from that area. If I am successful in recording it, I'll post it here.

 

There is no inspection cover.

 

That dm setup is there for a reason- if it's good, you are well advised to keep it in service. The dm technology is used on several premium Euro makes and smooths trans and clutch operation when there is some distance between the input shaft and secondary shafts in the trans.

 

What is #3?

 

I stand corrected- haven't been under there in a while, but I recalled that there is no stamped-type 3-dimensional cover, the kind that looks like half a bowl, in this setup. Forgot about the flat plate. But given that the clutch is recessed into the flywheel, I don't think there is much to see by removing that plate, on the engine side of the wheel. Possibly we can tell if there is any play there. I do have the wheel/ clutch that was removed, in working order, and we'll look at that before disassembling the car.

 

Given the situation you're faced with (possibly having to leave the car outside at the shop, where it's ripe for pickings), and that you have a shop with a lift, if I were in your shoes I'd buy a decent transmission jack and have at it myself at home. It's not a horrible job if you have a full-height lift. OTOH, I can't recommend doing it on your back. I did mine on a Kwiklift, and promised myself I'd never do that again. The ZF is one heavy beast of a gearbox, but if you can remove it with a trans jack, and leave it on there while dealing with whatever else is necessary, that becomes a non-issue. Mine stayed on the jack for the duration of the work I was doing.

Good luck with it. Let us know what you find after the teardown.

Live well,

SJW

 

Yes, I was involved in the trans rebuild back at the time, and even with full garage equipment and a tranny jack, that ZF box is a handful.

My thinking on this noise has changed somewhat, due to the fact that it comes only after the car has been driven a few miles. Yesterday I let it run in my garage for several minutes, long enough to get completely warmed up, and the ticking noise did not happen. Then I went out and drove for 5 miles or so, and by the time I got back the tick was there. Also it seems to me that there would be some difference in symptoms with the clutch engaged or not, but once it begins, there isn't any such change.

The flywheel/clutch theory was suggested by my mechanic friend, who subscribes to a diagnostic site that is apparently a compendium of oddball problems and solutions for the auto repair trade. He found a case, described only in words, of course, where a dm wheel failed at about 50k and had the same symptoms as mine. But given that mine has just 3k on it and my issue is temperature sensitive, and also that the case in that archive is just that- one case- I'm not yet convinced my problem is there.

I'm headed back to my mechanic friend's garage this morning to continue investigating, and I now suspect something is amiss in the cats or elsewhere in the exhaust system, externally or, more likely, internally- the cat(s), with the greatest temp change, being the prime suspect(s). I expect we'll run the car on his lift and listen underneath, then have someone in the car kill the engine while we look for the source of that staccato tick on shutdown.

Further details when available.

 

Pulled my gearbox the other Weekend and used the HF transmission jack. Made it really easy.

https://www.harborfreight.com/automo...ion-jacks.html