How to resurface ZF-6 Dual Mass flywheel?
03-28-2005, 03:54 PM
#1
Racer
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How to resurface ZF-6 Dual Mass flywheel?
I am replacing the clutch in my zf-6 and wondering how you resurface the dual mass flywheel? It doesnt appear that it comes appart.
03-28-2005, 04:43 PM
#2
Burning Brakes
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Technically you are not supposed to resurface it, but if it is to be done, make sure use a place that is experienced in resurfacing dual mass flywheels and has the proper fixtures. This is not something that can be casually done or you'll have major balance problems.
03-28-2005, 05:21 PM
#4
Team Owner
Originally Posted by ALLT4
Correct me if it's wrong but I think I remember reading on the forum recently that the amount you can take off is REALLY minimal because of tolerances.
A DMF is good for about 100k~120k miles, tops, before the masses start to come apart.
03-28-2005, 05:24 PM
#5
Drifting
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St. Jude Donor '05
the guys at my local shop said they would spot weld them together and then resurface them and grind the weld off afterwards.
I've got a 59k dual mass flywheel sitting here if you want it you can have it
I've got a 59k dual mass flywheel sitting here if you want it you can have it
03-28-2005, 07:41 PM
#6
Melting Slicks
Originally Posted by Kehrer923
I am replacing the clutch in my zf-6 and wondering how you resurface the dual mass flywheel? It doesnt appear that it comes appart.
03-28-2005, 09:31 PM
#9
Race Director
The big thing I was concerned about with my 40K dual mass flywheel was the tolerances allowed for rotation between the 2 masses. Mine was out of limits and it was not reusable.
03-28-2005, 10:14 PM
#10
Team Owner
that's the thing, there are two factors to keep in focus, the thickness and the condition of the masses.
What I really wish is that they were rebuildable. Meaning, someone could take the two masses apart, replace the springs and reassemble with a new clutch face. If that could be done and sold for a fair price, more would stick with it. They work very well, actually... just a bitch to replace.
What I really wish is that they were rebuildable. Meaning, someone could take the two masses apart, replace the springs and reassemble with a new clutch face. If that could be done and sold for a fair price, more would stick with it. They work very well, actually... just a bitch to replace.
03-28-2005, 10:31 PM
#11
Le Mans Master
Originally Posted by bogus
....someone could take the two masses apart......
I was unaware that it happened, but a shop resurfaced mine when I took it in for a clutch job(that was before I found the forum)
03-29-2005, 12:21 AM
#14
Team Owner
Originally Posted by 89 Paul in Cal
Got that part done, dunno 'bout the rest
I was unaware that it happened, but a shop resurfaced mine when I took it in for a clutch job(that was before I found the forum)
I was unaware that it happened, but a shop resurfaced mine when I took it in for a clutch job(that was before I found the forum)
03-29-2005, 12:39 AM
#15
Burning Brakes
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There have been numerous tests and comparisons on lightweight flywheels as opposed to heavier/ OE flywheels. Under most performance oriented driving conditions (drag, circle track, and road racing) the lighter flywheels are always quicker or faster. They are easier on the engine and the drivetrain. The 40 pound slug of a flywheel on ZF6 cars was designed just for the ZF6. T56's and 4plus3's don't use them. By nature, the ZF6 is a noisy, rattling, but strong transmission. The gears are cut with a little less helical arc, making them stronger, but also noisier. At the time, and because of the ZR1, GM badly wanted an alternative to the 4plus3 and weak T5, and the German built, badass, ZF6 was the only useable and available option. The problem was the noise that the race inspired tranny made when not under a load (idling and light cruising in 6th). The dual mass flywheel was the answer. By design, it acted as a vibration dampener and noise 'shock absorber'. By luck, its liberal weight helped clutch engagement when the car was sitting still and allowed for relatively low RPM takeoff by using it's momentum to keep the transmission from stalling the engine. That meant any spoiled rotten, clubfooted teenager or 'numb below the waistline' rich, old geezer could drive the car without killing it at every stoplight. It was a smart idea, but it is grossly overweight and does not belong in a true performance car. I am confident we all know how to drive a stick in traffic, so buy a 12.5 pound aluminum flywheel (the clutch surface IS removeable/ replaceable) and enjoy 10 to 20 'free horsepower' and another 600 to 800 RPM. And when people ask what is rattling in your car, tell them it's your ultra-stout, super-expensive, German built, road racing transmission. Can somebody out there give me an "Amen, Brother!"?
03-29-2005, 12:58 AM
#16
Drifting
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St. Jude Donor '05
Originally Posted by 500hp
There have been numerous tests and comparisons on lightweight flywheels as opposed to heavier/ OE flywheels. Under most performance oriented driving conditions (drag, circle track, and road racing) the lighter flywheels are always quicker or faster. They are easier on the engine and the drivetrain. The 40 pound slug of a flywheel on ZF6 cars was designed just for the ZF6. T56's and 4plus3's don't use them. By nature, the ZF6 is a noisy, rattling, but strong transmission. The gears are cut with a little less helical arc, making them stronger, but also noisier. At the time, and because of the ZR1, GM badly wanted an alternative to the 4plus3 and weak T5, and the German built, badass, ZF6 was the only useable and available option. The problem was the noise that the race inspired tranny made when not under a load (idling and light cruising in 6th). The dual mass flywheel was the answer. By design, it acted as a vibration dampener and noise 'shock absorber'. By luck, its liberal weight helped clutch engagement when the car was sitting still and allowed for relatively low RPM takeoff by using it's momentum to keep the transmission from stalling the engine. That meant any spoiled rotten, clubfooted teenager or 'numb below the waistline' rich, old geezer could drive the car without killing it at every stoplight. It was a smart idea, but it is grossly overweight and does not belong in a true performance car. I am confident we all know how to drive a stick in traffic, so buy a 12.5 pound aluminum flywheel (the clutch surface IS removeable/ replaceable) and enjoy 10 to 20 'free horsepower' and another 600 to 800 RPM. And when people ask what is rattling in your car, tell them it's your ultra-stout, super-expensive, German built, road racing transmission. Can somebody out there give me an "Amen, Brother!"?
Amen brother!!!!! I've got the Fidanza and it really wakes up the LT1 my car revs fast now
03-29-2005, 01:33 AM
#17
Team Owner
Originally Posted by 500hp
There have been numerous tests and comparisons on lightweight flywheels as opposed to heavier/ OE flywheels. Under most performance oriented driving conditions (drag, circle track, and road racing) the lighter flywheels are always quicker or faster. They are easier on the engine and the drivetrain. The 40 pound slug of a flywheel on ZF6 cars was designed just for the ZF6. T56's and 4plus3's don't use them. By nature, the ZF6 is a noisy, rattling, but strong transmission. The gears are cut with a little less helical arc, making them stronger, but also noisier. At the time, and because of the ZR1, GM badly wanted an alternative to the 4plus3 and weak T5, and the German built, badass, ZF6 was the only useable and available option. The problem was the noise that the race inspired tranny made when not under a load (idling and light cruising in 6th). The dual mass flywheel was the answer. By design, it acted as a vibration dampener and noise 'shock absorber'. By luck, its liberal weight helped clutch engagement when the car was sitting still and allowed for relatively low RPM takeoff by using it's momentum to keep the transmission from stalling the engine. That meant any spoiled rotten, clubfooted teenager or 'numb below the waistline' rich, old geezer could drive the car without killing it at every stoplight. It was a smart idea, but it is grossly overweight and does not belong in a true performance car. I am confident we all know how to drive a stick in traffic, so buy a 12.5 pound aluminum flywheel (the clutch surface IS removeable/ replaceable) and enjoy 10 to 20 'free horsepower' and another 600 to 800 RPM. And when people ask what is rattling in your car, tell them it's your ultra-stout, super-expensive, German built, road racing transmission. Can somebody out there give me an "Amen, Brother!"?
My suggestion is to use the GM F-body SMFW. this unit weighs about 20lbs. A nice weight for a street car FW.
Many drag racers have found that the fidenza is also too light for launch. I understand that the fidenza is great for road courses, tho.
03-29-2005, 02:15 AM
#18
Le Mans Master
Originally Posted by bogus
I was right! It IS a rubber membrain.
There is no dampening material inside that I can see being ruined by cutting fluid either. It's just a spring inside kept lubricated by grease.
03-29-2005, 02:39 AM
#19
Originally Posted by 500hp
There have been numerous tests and comparisons on lightweight flywheels as opposed to heavier/ OE flywheels. Under most performance oriented driving conditions (drag, circle track, and road racing) the lighter flywheels are always quicker or faster. They are easier on the engine and the drivetrain. The 40 pound slug of a flywheel on ZF6 cars was designed just for the ZF6. T56's and 4plus3's don't use them. By nature, the ZF6 is a noisy, rattling, but strong transmission. The gears are cut with a little less helical arc, making them stronger, but also noisier. At the time, and because of the ZR1, GM badly wanted an alternative to the 4plus3 and weak T5, and the German built, badass, ZF6 was the only useable and available option. The problem was the noise that the race inspired tranny made when not under a load (idling and light cruising in 6th). The dual mass flywheel was the answer. By design, it acted as a vibration dampener and noise 'shock absorber'. By luck, its liberal weight helped clutch engagement when the car was sitting still and allowed for relatively low RPM takeoff by using it's momentum to keep the transmission from stalling the engine. That meant any spoiled rotten, clubfooted teenager or 'numb below the waistline' rich, old geezer could drive the car without killing it at every stoplight. It was a smart idea, but it is grossly overweight and does not belong in a true performance car. I am confident we all know how to drive a stick in traffic, so buy a 12.5 pound aluminum flywheel (the clutch surface IS removeable/ replaceable) and enjoy 10 to 20 'free horsepower' and another 600 to 800 RPM. And when people ask what is rattling in your car, tell them it's your ultra-stout, super-expensive, German built, road racing transmission. Can somebody out there give me an "Amen, Brother!"?
Yeah I tell 'em it's a race tranny too! 
03-29-2005, 03:27 AM
#20
Team Owner
Originally Posted by 89 Paul in Cal
No, it is a thin metal. Like tin.
There is no dampening material inside that I can see being ruined by cutting fluid either. It's just a spring inside kept lubricated by grease.
There is no dampening material inside that I can see being ruined by cutting fluid either. It's just a spring inside kept lubricated by grease.
I wonder if it can be repaired.