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Dual Mass Flywheel
#1
Does anyone have any experience with Dual Mass Flywheels in Diesel Fords ?  I've got a 1997, non super duty, F350 7.3 Powerstroke in need of a new clutch. I bought it used, so don't know what is in there currently and it has over 300,000 miles on her, so the clutch / flywheel may have been replaced before I got her.

Anyhow, the truck originally came with a Dual Mass Flywheel, which is no longer made by Ford. After Googling around, and looking at Ford Truck Forums, there is a log of conversation about converting to a Single Mass Flywheel. The Dual Mass was basically designed to smooth out the vibration and noise from the Powerstroke Diesel from getting to the transmission, a 5 speed manual. But apparently, there were many issues with longevity and other problems because of the inherent complexity.

When I got the truck, it had a ball in the bed for a goose neck trailer. It is only 2WD so I assumed that it was used for hauling a trailer of some sort, camping or horse, etc. Since it has so many miles, and if it is still the original Dual Mass, it would prove that there is nothing wrong with putting another back in. If there was an Ford replacement, I would not even hesitate, but now I don't know which way to go.

There are a lot of Dual to Single conversation kits out there, But I finally found a couple places that can supply Dual Replacements. They are more expensive, but i am willing to pay that in order to keep the noise down. The truck has plenty of engine / transmission noise already (but maybe that is because it already has a Single Mass, or the Dual Mass is getting ready to blow, which makes them noisy. )

Any advice would be greatly appreciated.


[Image: IMG_0195.jpg]

73 ragtop, 1999 Mustang Bright Atlantic Blue Paint, Phoenix Engine 302-335HP,  Edelbrock Carb & Performer manifold; c4 with 2000 stall and shiftkit; 3:55 auburn limited slip differential, Hedman shorties; Car Chemistry Exhaust

Classic Air; Tilt Steering Wheel; 1999 Chrysler Sebring bucket Seats ; power windows;
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#2
mudbilly, your truck was the predecessor to the 99/Super Duty Series (F-250 through F-550) and was as tough as they came. The 6.9  and 7.3 diesels set the bench mark for light truck diesel performance.
The  dual mass flywheel (DMF) was a well engineered but complex and expensive part of the clutch system.  it was designed to absorb vibrations from the engine through the transmission and on through the rest of the drive train. These vibrations while always present in diesel vehicles were more noticeable in the smaller pick up size trucks. The DMF also helped  minimize gear roll over noise generated in manual transmissions that were filled with the thinner less noise absorbing automatic transmission fluid. It's called a dual mass flywheel because there are two plates joined by a bearing and damping spring assembly that also included a friction pack. The first plate mounted to the crankshaft and had the starter ring gear on it. The pressure plate bolted to the second plate.
These type of flywheels for the most did as they were designed to do for several hundred thousand miles. These flywheels were not recommended to be used with any high performance applications or towing where the weight of the towed load would exceed the recommendations of the vehicle manufacture. I have seen Super Duty's so overloaded that they actually busted and broke the center of the clutch disc out!!  
The replacement cost of the DMF was originally in the $500.00 range. When discontinued by Ford they were at $1686.73 (Ford part# F7TZ-6477-DA)
I would suggest looking at "LUK" replacement parts. I have purchased parts and kits from them for shop use when converting back to the single solid flywheel.
Another thing to keep in mind if you do decide to stay with a DMF (if your truck still has one) is that you have to replace the  DM flywheel when doing a clutch job as they can not be resurfaced.
Hope this has helped some and not made making a decision worse!!     Big Grin

Steve

No Officer...I really don't know how fast I was going, my speedometer stopped at 140!
[+] 1 user Likes secluff's post
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#3
Secluff-

Great info !!!!!

From my perspective sure sounds like an auto trans would be better behind a powerstroke!

So are the automatics preferred or better?

Ray

1971 Boss 351  
1972 Q code 4 speed convertible 
1971 Mustang Sportsroof  351-2V FMX 
1973 Mach 1 (parts car)
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#4
Ray, at the time mudbilly's truck was built, a large percentage of  Super Duty's were M/T. The C6 was the only A/T choice and was fine unless you were concerned with fuel mileage. The C6 was tough as nails but was a 3 speed and didn't offer the fuel mileage advantage the 4sp manual did and was more trouble to install a PTO such as wrecker drivers needed.
Another thing a furniture store owner told me was the difficulty of hiring new drivers that could drive a manual transmission truck! The trucks he did have with M/T and in combination with some "Cowboy" drivers were always in the shop with clutch and transmission damage. So the A/T is preferred and better for fleet owners that were looking for less maintenance since the new automatics were actually "Truck" transmissions.
The transition to all automatics started in 99 when Ford released the E4OD which was a specifically designed truck 4sp automatic transmission. There were many engineering changes and upgrades over the years while the manually shifted trucks slowly disappeared from sight. Now you can only get a six speed TorqShift automatic in all Super Duty trucks except the F650/750 series!

Steve

No Officer...I really don't know how fast I was going, my speedometer stopped at 140!
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#5
Well, I wound up ordering a new Dual Mass Flywheel & clutch kit. I am just afraid to do the Single Mass Fly wheel conversion because of the noise & vibration concerns.

Now I just have to find a shop that will install it.

73 ragtop, 1999 Mustang Bright Atlantic Blue Paint, Phoenix Engine 302-335HP,  Edelbrock Carb & Performer manifold; c4 with 2000 stall and shiftkit; 3:55 auburn limited slip differential, Hedman shorties; Car Chemistry Exhaust

Classic Air; Tilt Steering Wheel; 1999 Chrysler Sebring bucket Seats ; power windows;
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