Dual Mass Flywheel again?

[crafty]

It appears that I may have a problem with the Dual Mass Flywheel again. Tonight the truck started to shake while at an idle when I was picking up the mail. It has been almost 6 years since they replaced the last one.
So, am I asking for trouble if I keep driving it for a while if the shake continues?
When I do replace it, should I go with another DM flywheel or look at trying to convert it?
Also, would you go to the dealer for this work or would you go to a Transmission shop? We have a very good one in town and I think I will get their opinion no matter what but I wanted to see what people here thought as well. It is CAA approved and has been around for over 30 years.

There is 207400 km on the truck and the clutch was replaced the last time as well so it was all new in August 2005. I think I own the only 6 speed my dealer has sold but they did a great job when they worked on it last time.

Any advice would be greatly appreciated.

[Kennedy]

That's a tough one. Not many ZF'ers out there. South Bend has been the name in clutches, but be prepared. I hear stories of how great their customer service is, BUT that is because there was a problem with the product. Where have we seen this before?

I would ditch the DMF in a heartbeat although you seem to be doing fairly well with it. There was a guy several years back went by CPmac632 on the forums. He pioneered much of this stuff and had a reputation for quality, just lacked production and business financing as i recall.

As for driving with the shake, it's hard to gauge without seeing and feeling it, but it's the near equivalent of having a failed harmonic balancer so I would be inclined to park it.

[More Power]

The early manual transmission-equipped 6.5L turbodiesel powered trucks originally came with a dual-mass flywheel. They failed in large numbers too, and GM eventually designed a new single-mass flywheel and matching pressure plate and clutch.

GM didn't learn from their previous mistakes... I was a bit perplexed when the first 2001 Duramax/ZF trucks arrived with a DM flywheel... Those fw's failed just like those on the 6.5's did.

The single-mass flywheels used on the 6.5 had a pretty good track record, as I recall.

Always replace the pilot bearing when the truck's apart.

Jim

[rapidoxidationman]

and check the input shaft of the transmission too... Mine was egged after the DMF had it's way with the pilot bearing.

[crafty]

Thanks for the replies and suggestions so far. Tonight is a week since it had the shake and it hasn't done it again. I called the dealer parts dept last Wednesday and got prices for doing the repair just so I could break it to my wife :eek: I had to tell her on the weekend because she asked me straight out how much money I may have to spend on the truck in the coming months. She took it better than I thought.
Yes, I think I'm doing okay with the flywheel. Six years isn't too bad but when I had my 6.2 standard I went 15 years and 315,000 kms and never had to repair anything in the drivetrain at all. I suppose I could just assume that it will happen every six years and live with it.

So here are the prices for all the parts. The number in brackets is the list price.

Flywheel - $880 ($1100)
Clutch - $650 ($812)
Throw-out Bearing - $340 ($425)
Bolts (8) - $48.00
Pilot Bearing - $88 ($110)

Labour - Approx 6 hours $550

So, when you add it all up with taxes etc it will be about $2900 to replace everything. I don't know if the clutch will need replacement and I do have the clutch from the last time that I could always put in to save a few bucks. It is still in good shape. Does the amount of time to do the work sound about right?
I will keep you informed of what happens.

[More Power]

I don't know if the clutch will need replacement and I do have the clutch from the last time that I could always put in to save a few bucks. It is still in good shape. Does the amount of time to do the work sound about right?
I will keep you informed of what happens.

We've R&R'd an Allison in a 4WD truck in about 4 hours - a few times. I haven't had an opportunity to work on a ZF...

Are you replacing the DM with another DM? Do they make a single mass flywheel for the Duramax? I know that when replacing a 6.5 dual mass flywheel with the newer single mass flywheel, it requires a matching pressure plate and clutch plate.

Jim

[rapidoxidationman]

Tonight is a week since it had the shake and it hasn't done it again.


As the DMF on my '96 6.5 was failing, I would feel a shake only every now and then and it would go away if I did a serious engine brake or blip the throttle in neutral. Until one day... The shake wouldn't go away. Dealer said it felt like the engine was missing. I felt the engine ran fine, so I drove away.

Took it to someone I trust, tranny got pulled, and the DMF had lost about half of the bearings seperating the two masses, causing the two disks to have centers that were no longer on the same axis.

That was an expensive fix.


If there was a way to lube the bearings, DMF's might be a good idea. But there's not, and they're not.

My $.02