Has anyone heard about the reliability of the LUK single mass flywheel conversion for 94-97 PSD? I installed a couple of them in my work trucks because they have a lot of idle time and I was tired of buying 800 dollar flywheels. I have heard the single mass is bad for the ZF, but I've had no problems so far. Just wondering if I should continue to switch over John

 

As far as I know the only problem with the use of the single mass flywheel is increased gear noise from the transmission.

 

There are also increased engine vibrations from about 2400rpm and up.

Les

 

The Luk upgrade is a tremendous improvement over the stock unit. If you have installed a few in work trucks and have taken the time to drive one of those work trucks you will be able to tell a considerable difference in the feel and driveability. As for the trany you do have the possibilty of gear rollover noise. This sound is not harmful to the trany, in fact it is present with the dmfw, you just don't hear it because the noise does not transfer from 1 side of the dmfw to the other. Gear rollover noise occurs to some extent in eery ZF trany be it in the Ford diesel or the BMW car. I currently have in excess 2,500 unit in the market without any problems.

 

What's this about engine vibrations over 2400 RPM's? Tell me more Powerstroke250. I have a '93 which is going to need a new clutch fairly soon and I was planning to put the LUK kit with the solid flywheel in it. Is this not advisable due to this vibration? Also are there any upgrades to the tranny I should consider while I have the tranny out? I tow about 8-12thousand pounds when I tow with the truck and I plan on keepin' her for a while.

 

Jackson,
I don't know anything about the 1993 trucks or what flywheel is in them. I do know that on the 1997 PSD truck I drive at work, the vibrations are present at 2400rpm and over. Much moreso than with the DMFW. Afterall, that was the purpose of the DMFW, to reduce engine vaibrations and torque spikes to the drivetrain. As for longevity of the drivetrain components I cannot comment on, I've only got 5000 miles on the LUK unit.

Les

 

Mine does have the dual mass flywheel on it. Is the vibration enough that you are disappointed in switching over?

 

The vibration is more pronounced from 1st to 3rd gear then it smooths out somewhat in 4th and 5th. The vibration is no reason not to get the LUK. It IS a good setup with a super light clutch pedal effort.

Les

 

Thanks for your input Powerstroke250.

 

I'm also going to have to replace my dual mass flywheel very soon (like immediately!!). From what I hear, the LuK is the way to go.
If the only thing I'm giving up is a little peace and quiet, and I'm
getting a stronger, easier-shifting unit, then that's great. If the LuK is harder on the tranny, then I'm not so sure. Mr. Clutch, what's your opinion? Anybody else have one?

rotorhead

 

Rotorhead
I have heard a few talk about a vibration and in some trucks this could be possible. As for being harder on the trany I doubt it. I have somewhere between 2500 - 3000 units in the market place with several already having replaced the clutch and to this date no problems. I believe the vibration is a result in some cases of either end play in the crank or input shaft brgs. When the dmfw goes bad many owners continue to drive their trucks with no idea that the dmfw is no longer working properly and in many cases they may become slightly unbalanced due to loose pieces inside the 2 halves. Now you have a 70lbs mass being run for sometimes thousands of miles in some case an unbalanced state. This can cause damage to main brgs and or input shaft brgs. This may be the vibration culprit because only a handful of owners have mentioned any vibration. If the clutch and or flywheel were unbalanced causing the vibration it would be evident on every installation. The Luk unit is a far superior unit to the dmfw unit in performance, torque capacity, driveability, and cost. As powerstroker mentioned the pedal feel is more like a toyota car than the stiff pedal you have been accustomed to. I hope this helps. If you need any further explanation, information, or help email me directly or give me a call.

 

Sorry guys, I've been on sabatical, I have installed 2 LUK conversions in 93 F-450's with the 7.3 non-turbo, both have about 10,000 miles and 2 in 95 and 97 F-450's with the DIT. One only has 5,000 miles, but the 97 (which broke the tranny case due to the dual mass going bad) has about 40,000 with no problems. The person who drives this truck every day says the worst thing was getting used to the soft pedal as he kept letting the clutch out too fast and killing the engine. It is a remarkable difference and the noise is minimal. I think most of the noise from our trucks is because of the 5:13 and 4:88? gear ratio. When I first posted this I didnt realize I had that many miles on the 97. It was constantly in for clutch repair, and no problems since. Oh, and I also found out one of the worst things you can do to a DIT with the dual mass is let it idle, and our trucks do a lot of that, so I think the new setup will be nice.

John:7

 

I like your signature, John. I'm going to have to write that one down.