solid flywheel?
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Posting Guru
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From: Quesnel, BC, Canada
Originally Posted by Dave Sponaugle
87 6.9 with the ZF5 had a dual mass flywheel.
All of the ZF 5 equiped trucks had them.
I have run a 6.9 flywheel and clutch disc behind a 7.3 turbo motor with my 4 speed without problems, it bolts right up. (same crankshaft in the 7.3 and 6.9 motors)
All of the ZF 5 equiped trucks had them.
I have run a 6.9 flywheel and clutch disc behind a 7.3 turbo motor with my 4 speed without problems, it bolts right up. (same crankshaft in the 7.3 and 6.9 motors)
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Had Mine Replaced Last Year This Month. The Guy At The Tranny Shop Said I Had A Smf And Should Be A Dmf So They Put In A Dmf [$1138.00]. Also Replaced Pressure Plate. Had A Bad Chattering Prob. After The Repairs, Seemed To Fix The Problem. How Long Should I Expect The Dmf To Last?
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From: Quesnel, BC, Canada
How you drive, and how smooth you shift will determine the lifespan of the DMF. My trucks a 96, had 230,00km on it when I bought it in 2005 and the DMF was gone then. I wouldnt plan on getting more then 10 years out of one. It might not be shot in 5 years but I'll bet its tired. Now Im no expert, someone more knowledgeable will chime in if Im innacurate.
Post Fiend
Joined: Nov 2003
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From: Nutter Fort, WV
Since we all live in different areas and do different things with our trucks it would be hard to estimate DMF service intervals.
I load very heavy, drive rather fast and live in the mountains.
I got 250,000 miles out of my original clutch, and it was just starting to slip when the throw out bearing died. So I replaced the clutch disc and pressure plate with the throw out bearing.
I have friends that have dual mass flywheels that haul almost as much weight as I do, they are lucky to get 15,000 out of theirs.
I load very heavy, drive rather fast and live in the mountains.
I got 250,000 miles out of my original clutch, and it was just starting to slip when the throw out bearing died. So I replaced the clutch disc and pressure plate with the throw out bearing.
I have friends that have dual mass flywheels that haul almost as much weight as I do, they are lucky to get 15,000 out of theirs.
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I Do Not Haul Much At All. Using As Daily Driver For Now, Hoping To Change That Soon. I Only Drive 26 To 30 Miles Round Trip To Work & Back Home, Church On Wed. & Sunday, And Whatever Other Running Around I Do. My 7.3l Doesn't Like Cold Weather. When It Drops Below 25 Degrees I Try To Leave It Pluged In. Don't Like To Start When She's Cold. My Only Transport For Now. Try To Get Another Vehicle B 4 Winter. Bob.
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From: South West Michigan
I just pulled my zf out of my 91 f350 7.3. The clutch did not disengage easily and chattered when engaging.
The flywheel looks good and the springs on the ring gear side of the dmf look o.k.
I thought that I would just replace the throw out, disc and pressure plate. Am I making a mistake by not replacing the fly wheel based on visual inspection. ???
mf
The flywheel looks good and the springs on the ring gear side of the dmf look o.k.
I thought that I would just replace the throw out, disc and pressure plate. Am I making a mistake by not replacing the fly wheel based on visual inspection. ???
mf
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From: West Valley Utah
Personal view.....there is no way I would go to the trouble of pulling a trans and not get rid of the duel mass flywheel, especially one that had a few miles on it.
People drove trucks and pulled heavy loads for years and years, why do we suddenly need to be protected from ourself in the form of a fall apart flywheel? Maybe just me but I don't get it!!
People drove trucks and pulled heavy loads for years and years, why do we suddenly need to be protected from ourself in the form of a fall apart flywheel? Maybe just me but I don't get it!!
Post Fiend
Joined: Nov 2003
Posts: 21,285
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From: Nutter Fort, WV
mistaken ID,
Most of the reason is this.
When the trucks were equiped with solid flywheels the transmission was made of cast iron, AKA T 19. That is probably the most bullet proof transmission Ford used behind a diesel engine.
Then with the ZF 5 and ZF 6 the transmission case was aluminum, we all know that aluminum is no where close to being as strong as cast iron. So since the transmission was not as strong, the metal was much softer, we needed to protect the transmission from strong torque pulses at lower RPM. So we design a flywheel that has extra springs to dampen the pulses.
I would not tear one down just to get rid of the dual mass flywheel.
But if I had to buy a new dual mass flywheel, you can bet a solid flywheel would replace it.
Most of the reason is this.
When the trucks were equiped with solid flywheels the transmission was made of cast iron, AKA T 19. That is probably the most bullet proof transmission Ford used behind a diesel engine.
Then with the ZF 5 and ZF 6 the transmission case was aluminum, we all know that aluminum is no where close to being as strong as cast iron. So since the transmission was not as strong, the metal was much softer, we needed to protect the transmission from strong torque pulses at lower RPM. So we design a flywheel that has extra springs to dampen the pulses.
I would not tear one down just to get rid of the dual mass flywheel.
But if I had to buy a new dual mass flywheel, you can bet a solid flywheel would replace it.
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Ok, I've had a couple glasses of wine but this dual mass fly vs a luk set up seems like a no brainer to me...right now I have a 6.9 non turbo IDI with a 4 speed, eventualy upgrading to a 5speed...from what I have read there is some noise issues with the luk setup but have read nothing but horror stories about DMF's...not once have I read that a solid fly wheel resulted in a failure of any drive line, pinion, tranny etc...so gentlemen, please correct me if I'm wrong [the wife says I'm brainless, but what does she know, she married me] SMF is the way to go?!!