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View Full Version : Flywheel Replacement Cures Engine Vibration



crafty
08-29-2002, 18:25
On July 31st I got my truck back after getting the Flywheel replaced. It was done to cure the "vibration" condition that I was experiencing sometimes when the truck was sitting at an idle. This problem only happened occasionally, about once or twice a week. In the month since then I haven't had any recurrance.
This seems to be a 6 speed problem only. The fix was reccommended by GM Powertrain after they were sent data and a description of the problem. The work order states that an updated flywheel was installed so there may be a problem with some of the other flywheels as well.
I would suggest that if you are feeling your truck shake or vibrate when stopping at stoplights or just idling in the driveway, ask your dealer to look into a new flywheel. You will know when it does it because the gearshift shakes and if you pop the hood, the whole engine is shaking too. All the shaking stops when the engine is put under load or you barely touch the throttle.
:D :D :D

MEP
08-29-2002, 19:02
Crafty,

I believe you and me are the only ones who have experienced THIS vibration. (Not to be confused with the "Lopey Idle") Mine has gone away for the time being, but I'm sure it will come back. I'm going to hold off as long as I can before I go to the dealer. Maybe there will be a service bullitin out documenting this problem.

MEP
DP member # 739

Landscaper
08-29-2002, 20:11
Hmmmm I've noticed something similer but chalked it up to being a diesel. I'll have to pay more attention.

Is the updated flywheel a 1 piece? Or is it another dualmass piece of junk.

[ 08-29-2002: Message edited by: Landscaper ]</p>

crafty
08-29-2002, 20:20
I never got to see the new Flywheel before it was put in so I don't know for sure. I'll talk to the tech the next time I drop by the dealer and ask him if it is a Dual mass or not.

1BADDMAX
08-29-2002, 20:30
I've got 34k on my truck and haven't had any type of vibration. How many miles do you all have on your trucks?

crafty
08-30-2002, 04:08
I've got 35,000 kms and the tech was told that it has been showing up at the 30,000 mark. If you have made it past that, it's a good bet that you may be alright. :D :D :D

elowe1
08-30-2002, 12:04
Love that flywheel.
I had a problem where between 1/4 and 3/4 clutch travel it would make a terrible grinding sound.
The flywheel was replaced at 12000 miles and the problem went away. Now at 24000 miles It has been replaced again for the same syptoms.
I hope this one lasts

MEP
08-30-2002, 17:20
My vibration showed up at 24,ooo miles.

Landscaper, if you have this problem you will definatly notice it!

MEP
DP member #739

CPMac632
08-30-2002, 22:26
My truck also had a terrible grinding sound between 1/4 and 3/4 of the way down. Have put about 3K on it since and no further problems. They replaced my flywheel with another Dual Mass. Does anyone have a flywheel that is bad that they kept or can still get a hold of if so e-mail me.

MEP
10-21-2002, 18:40
Crafty,

It's been a while but has that flywheel replacement you had a while back permanently cured your engine vibration problem?
I still have mine and I've let the dealer flash the ECM twice and both times the problems came back a week later. I'm going in for the third time this week. Do you or any body else know if there is a service bulliten out on this?

MEP
01 Dmax/ZF

Wally
10-21-2002, 19:46
Is there any relationship to this and the delayed clutch release? Delayed clutch release you ask? I don't know what the heck it actually is but sometimes when I push in the clutch especially in a situation where the driveline is loaded, uphill downhill etc., it doesn't seem to disengae immediatly and when it does it is accompanied by a driveline/motor mount rattle that sounds like everything has just hit the solid portion of the flexible mounts. I have heard other members report the same phenomenon.
I am getting very disgusted with this manual combination.
It has no bullet. Wouldn't pull a string out of a cats butt below 2 grand.
Rattles slams and bangs.
The entire clutch system feels like an engineering after thought!!!
Two dealers in my area and both say its perfectly normal. No way this rattling, bouncing, gutless pile is normal!!!! :mad: :mad: :mad:
Yes I did drive two before I ordered the manual and neither one acted like this. Stuck in an area with two marginal dealers. I will never get this resolved.
Sorry for the rant.

spctr13
10-21-2002, 21:32
Dual mass replaced @ 35900 and again @ 52000 miles . Now @ 57500 . Total of four flywheels sent to the dealer , two came through "busted " .

Mac

C J Fairall
10-21-2002, 22:48
Wally;
The noise and conditins you just described match what my truck was doing, especially declutching during deceleration. I changed the dual mass flywheel and cured the problem. When I took the flywheel out I found the cushion springs had collapsed, allowing the two halves of the flywheel to move in opposite directions at the same time. What a loud rattle noise and embarrassing too. This had been going on for about 10K miles, the truck now has 36k miles and is now quiet with smooth shifts again.
My service manager where I work told me about an adminsitrative message on the topic, so I expect to see a bulletin soon.
Jim

needbigtruck
10-22-2002, 02:59
Crafty, I don't know if you were having any problems with the "hard" clutch pedal (kind of like what Wally says) after driving for a while then having to push in the clutch. I have a new master/slave cylinder waiting for me at my dealers, but I am not convinced they are the problem. I believe heat is being created down there and that is affecting the hydraulic fluid, so the new cylinders are not the solution. If there is something wrong with the flywheel then that could be the culprit?

DieselsRule
10-22-2002, 15:00
NEED BIG TRUCK

Just got mine back for the hard clutch when hot.
Had pressure plate and slave cylinder replaced. Still makes those crazy sounds from hell like it is going to fall apart with all of that banging around down there but I tell you what, when I release the clutch now, this thing really locks up solid. What a difference with the way the truck launches. I can really feel all of that torque in this motor unlike the Alli, it is direct and this thing will run like hell when you bang through the gears. Not like the sloppy POS feeling I had before (I was almost sorry I got the ZF-6). I beleive it was the slave cylinder as the fluid would always turn black.

My only complaints now are -- slight clutch chattering when starting from a stop and all of that noise. Now that I hear about the flywheels collapsing, I will bring it to my dealers attention and get a response from them.

Service writer wrote up -- Slipping clutch on the ticket.

[ 10-22-2002: Message edited by: DieselsRule ]</p>