[nboehm]

My dual mass flywheel is shot, and I was thinking about doing the lucky conversion, but then I would have to buy a new clutch because the clutch I have has no springs on it. My main question is, will a 6.9 flywheel work for this? I would rather use a solid cast part than bolting somthing together. With my luck, I could see the bolts coming apart and messing more stuff up than before. Im just trying to figure the cheapest, yet smart way to do this. Thanks alot

 

[94_turbo]

doesnt the lucky use nylock nuts--if so-and your still nervous--get regular locking nuts-they wont come loose--and if your still nervous--put a drop off blue loctite on the threads before you tighten the nuts---

 

[jrfastbanshee]

I second the 6.9 flywheel on the zf tranny question. Right now I have the dual mass mounted on a 6.9 with a zf behind it and I think things are a little out of balance. But it could just be me outta balance. /ubbthreads/images/graemlins/tongue.gif I would rather slap the 6.9 flywheel on there and be done with it.

 

[nboehm]

I want a long term fix. I just find it hard to belive that bolts under so much stress (espically from the way I drive and the stuff I tow) wont come lose or shear in any way, shape, fourm. I just think it would be easy as heck to just toss a 6.9 flywheel in their, that is, if it will work.

 

[Greg77]

Do some looking around. I didn't want to spend a bunch of money on my E4OD switch, I found a clean dual mass that had recently been replaced and the truck was parted out for $100.00. I know where there are a couple of more, so they are out there. Luk had the cheapest clutch kit for the dual mass and they have springs in the disk.

Greg

 

[jaybee]

According to Ford there is a difference in the counterbalance amount between a 6.9 and a 7.3, so you really shouldn't use a 6.9 FW on a 7.3. Having said that, I do believe some have done it....

 

[BenTaylor]

I tried the 6.9 Flywheel/springed clutch on the 7.3 with a ZF and it sounded like the transmission was going to fall out of the truck. Also the truck had a terrible miss from I assume it being balanced different..

 

[jrfastbanshee]

I have a stock 7.3 flywheel (dmf) on a 6.9 engine and there is barely a shake at 2000rpm. I have had worse shakes in the past...but I need to order up that springed clutch disc soon and put the 6.9 flywheel back on.

I wonder if the 6.9 flywheel just won't work with the zf5 for some odd reason? I have heard a couple horror stories now. I didn't measure them while they were side by side. /ubbthreads/images/graemlins/rolleyes.gif

 

[huskyhauler]

[ QUOTE ]
I tried the 6.9 Flywheel/springed clutch on the 7.3 with a ZF and it sounded like the transmission was going to fall out of the truck. Also the truck had a terrible miss from I assume it being balanced different..

[/ QUOTE ]

not sure of that one. the 6.9l as well as the 7.3l use the same crank and front balancer. both are internally balanced STEEL crankshafts, and have the same casting numbers. i have done quite a few 7.3l to 6.9l conversions on motors, and have NEVER had a balance or vibration problem. my 92 has a ZF tranny and a 6.9l motor in it. i have yet to feel a shake ever. i would take a closer look at the flywheel before i would rule a difference in balance.

 

[BenTaylor]

Are you still using the 6.9 flywheel between the motor and the tranny. I know you're saying you did 7.3 to 6.9. And I know from what I've read they're direct swaps, but in my case I used a new out of the box 6.9 solid flywheel, Spring loaded clutch set, new throw out and pilot bearing. When I started it up a freight train passing by had less vibration than what that truck put out. It also sounded like the motor had a awful miss, a "chug" noise. Kinda like what a swallowed valve on a 460 gasser would sound like. Just wondering if it works fine on a 6.9 but not for the 7.3L That'd be almost proof positive there is something different.

PS I have a rebuilt motor tranny and transfer case. Less than 31 miles on the rig after her revamp.

PSS: The noise and the miss left with the Luk Setup installed.