I converted my 97 PSD from a Dual Mass Flywheel DMF to a Solid Flywheel last week.
Have to say thanks to Cody for provising some valuable information and his friend Dan.
I must say that there is a substantial difference between DMF and SOlid flywheels.
The first is that fact that the ZF 5spd makes a lot of nise that the DMF dampens out. I have read here that some wonder what is happening. I was informed up front that this would occur by the company I purchased the clutch from.
It does change your driving habits. You will use lower gers more and as a result, your fuel mileage will drop some. Mine has dropped from between 17 and 18 to 15. I believe this is a two fold reason, one is the noise that the ZF makes when in hogher gers and low speeds as opposed to the dampened noise by the DMF. Second is the difference in rotating mass. The solid is some what lighter than the DMF.

I used a 13" heavy duty which may result in more noise due to the nature of the large springs of the heavy duty clutch. The clutch pedal feel is nearly the same as the DMF. Also, shifting wiull be smoe what less smooth in certain cases. More care need to be taken when changing gears to make sure synchronizers mesh well

I used a LUK flywheel and got the correct bolts with the clutch package. THey are shorter than the DMF bolts. THe alignment pin does not protrude past the surface of the Solid flywheel so thate is no issue here. I reused the ring under the flywheel bolts.

Used a new pilot bearing as furnished with the kit. The release(throwout) bearing was also replaced, that was the reason for opening up the project..it ddisintegrated into a dozen or more pieces. Sad part is that part of the bearing mount is plastic. Not a good place for plastic. This is part of the reason it failed.
No choice...all are the same.

The plessure plate was bolted tot he flywheel with new bolts also.

I dod the entire project without removing the down pipe..only unhooking it on both ends... Did remove the transfer case.

So far, have hauled 26000 CVW (Backhoe on trailer) and pulled out a dump truck that was stuck with half of load in bed (single axle dump) Clutch seems to work fine and other than the new sounds, no issues.
The DMF had over 300,000 on it and was a little loose. Not too bad. If you are only into pleasure and light towing, you may not want to change and if the DMF is solid, you may want to retain it. I have regularly pulled 26000 cvw with the DMF without any issues.

I know some have concerns after the swithch, and apparently no one told them about the noises.
Had a newer PSD drive by me today and it sounded just like mine. I asked him if he had swapped.. Answer..YES

One final note...when you idle in neutral, you will experience the most noise. Raising the rmp's slightly above idle will nearly totally eliminate the noise.
Am told, it should be reduced with clutch wear, especially the weaking of the disc springs.
ottom line..it is an individual preference. I will not recommend one way or the other.
I will answer questions regarding the project though.

Again..Thanks Cody and Dan.

 

i changed my last truck over to solid. the way i see it is it's a truck not a lincoln.if you want quiet buy a lincoln. are you sure your ZF isn't a little noisy because it's got 260,000 miles on it? bearings whiney? i changed the atf in my zf every 10,000 miles and i sold it with 211,000 miles on it and it was as quiet as a watch. it actually made more noise at lower rpms' when lugging it and such. i'd switch to solid again and not think twice about it. later, pete

 

the noise is due to the gears being whiplashed at idle , the engine at idle has significant power spikes at each firing cycle and accelerate the gears then slow them down in miliseconds its the reason the dual mass was used to begin with the ZF has massive gears which store a great deal of enertia

 

IMO, 300K miles is a perfectly acceptable duty life. Why did'nt you jsut stick with a new DMF?

 

how can you tell if a Dual Mass to Solid Conversion was done with out pulling trans my 94 idi make all kinds of nois at idle

 

You could pull the inspection plate on the bottom of the tranny/engine. Look up and turn the engine slowly. If it's a DM, you'll see the springs on the flywheel.

 

Two things I did to quiet mine down when I did the swap.

1) Just like racenitro said, bump up the idle. Mine is in the 750-800 RPM range and that made a big difference.

2) Use MORE and HEAVIER oil. I put 2 gallons of 15W50 Mobil 1 synthetic in mine. You can only put a gallon or so in if you're pumping it in through the fill plug on the side. I filled mine by removing the shift lever and pouring the second gallon in through the shifter "tower".

Between those two things, mine is as quiet as the original tranny EXCEPT when I lug it down to low RPMs - below that 750-800 RPM threshold...

 

at my work we had a roll back that used to eat up duall mass set-ups more often than single. truthfully the cost for single compared to dual alone made it worth doing the swap.

 

dual mass sucks hands down. you say a solid is bad? ask dave he has the old solid flywheel with the 4 speed and pulls alot more weight and makes alot more power than most people on here are making with idi's. i think you were just expecting way to much from something that has been known to make alittle more noise than a dmf

 

[QUOTE=racenitro] So far, have hauled 26000 CVW (Backhoe on trailer) and pulled out a dump truck that was stuck with half of load in bed (single axle dump) Clutch seems to work fine and other than the new sounds, no issues.

The DMF had over 300,000 on it and was a little loose. Not too bad. If you are only into pleasure and light towing, you may not want to change and if the DMF is solid, you may want to retain it. I have regularly pulled 26000 cvw with the DMF without any issues.

[QUOTE]

How can you make such a broad, sweeping statment. DMF does NOT suck. It sounds like racenitro got VERY good service out the OEM DMF.

Personally I would not go with a SMF. The DMF is there to protect your $2k ZF tranny. The deisel compression spikes will eventually wear the gears/bearings.

If you shop around, you can find an OEM Valeo DMF for around $550-600

 

i can say that because ive seen and pulled tons of dual mass flywheels from trucks with less than 200k and they are already shot maybe there have been people out there that every so often get alot of life out of a dmf setup. if not running a dmf is so bad for a transmission how come the cummins doesnt use one on their old setups. im just mearly stating that the statements against the solid flywheel are a bunch of non sense. my truck still has a dmf setup that the guy before me replaced and im going to run it till the clutch is gone, then ill probably either convert to a solid or convert to a e40d

 

I guess the people that designed the ZF tranny know nothing about flywheels?

I see trucks all the time that have very satisfactory service out of the DMF.

I'd say the people that don't get good life out them, prolly abuse the clutch. Prolly driving like a 16 YO.

 

when in my statement did i say the people who diesigned the zf no nothing about flywheels? im just telling you its not going to hurt running a solid flywheel. its like liberals and global warming scare they say one thing about it getting a tick warmer in temp for 1 month out of the year and get everyone in a panic. same with not running a dmf. basicly take what ford trans tech said and read it again. you would think he would have said not to run one if it was such a bad thing. don't like my oppinion thats fine. I never said the dmf is garbage. i just said it sucks hands down compared to switching to the cheaper solid setup.

 

There are several things that enter into this that have not been stated.

I would be willing to bet that 40% of the F 250 and F 350 trucks sold in the last three years have never been loaded to Fords max capacity.
If you were to back the calendar up to 1994, I bet the same statement would hold true or be very close to true.
Many of the trucks sold have nothing to do with working, it is a making a statement kind of thing.
The people that buy trucks to make a statement, don't want to have to spend money repairing a transmission bushing or a rear axle bushing.
The power spikes in the drive line will take out the bushings and bearings if you lug the engine down low on a regular basis.
They also do not want the transmission to sound like a dryer full of bolts when it is idling.
Enter the dual mass flywheel.
Transmission was quiet, warranty repairs went down on the transmission and rear axle.
Now the original buyer has traded the truck of on the newest latest greatest gotta have vehicle, and he was happy with the truck he traded off.

By now the warranty is expired, so the second owner who was probably looking for a truck more for work related duties.
He will also most likely keep the truck longer than the original owner did.
He is the one that will be mad when the dual mass needs replaced.

The fact I have a solid flywheel does not enter into this equation at all.
In 1986, the OEM flywheel was solid.
The transmission was cast iron.
And even though I have a cast iron transmission case, I did have to replace that 3 dollar bushing on the counter shaft.
I heard the whine in first and third gear and knew that if it was not fixed as soon as it started, it would cost a lot more to fix later.

Now if you really want something to think about, the extra fuel I burn with my 4 speed will pay for many dual mass flywheels since they were in trucks equipped with overdrive.

Why don't I swap to a ZF 5?
I don't think the ZF aluminum transmission case can stand up to me and what I do with my truck.

Fact of life, nothing is perfect for everyone.
What is perfect for me, some people would not find acceptable.
The same statement works the other way as well.
A while back, I was over at the Ford dealer, he had a nice 4x4 7.3 Stroke crew cab sitting there.
Leather seats, plush pile carpet, heated seats, automatic tranny, automatic hubs and all that fluff stuff.
Salesman comes running over, I can put you in this for.....
I just looked inside, if I had that truck out on a jobsite and had to run for parts I would do 2500 in damages just getting in, mud up to my waist.

I want rubber floor mats, vinyl seats and manual everything, that is just the way I am.

 

The IDI is in very good company with a DMF. I've worked on BMWs that came equipped with dual mass flywheels from the factory. It's not a poorly thought out design, they work very well . I can only imagine the failure rate is due to driver error, very few people really know how to drive a manual transmission properly, even less know how to do it right with a diesel. The cash heavy crowd who walked into dealerships and bought these things new, for the most part, had no idea how to operate a diesel and many tried to drive them around like a sports car. I'd be willing to bet that has more to do with the failure rate than the design.