Dual Mass Flywheel failure
10-20-2012, 01:26 PM
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Dual Mass Flywheel failure I have searched the forums and I have not found anything like this.
Symptoms:
Car will not engage into any gear with the motor running.
This started as a difficulty to get into reverse, but one day none of the gears would engage well, reverse being impossible.
With the motor off, everything shifts fine. Not buttery, but fine.
Clutch began to have a strange pedal feel around halfway through engagement. The best explanation was the engagement was not consistent.
Shop claimed it was a tranny issue, so I decided to pull it. My initial guess was pilot bearing or slave cylinder.
Tranny was interesting to pull. The shifter was a PITA and Kooks 1 7/8 makes tranny pulls VERY tough. It limits how much the motor can angle to get the bellhousing bolts and the bellhousing will not come off around without loosening the drivers side header. So once we tore it all apart, this is what we found:
The bolts and the holes do not allign for removal. Additionally, it is hard to see from the pictures, but the flywheel is not square to the pressure plate. There is a larger gap at the bottom than at the top.
Has anyone ever seen this?
Symptoms:
Car will not engage into any gear with the motor running.
This started as a difficulty to get into reverse, but one day none of the gears would engage well, reverse being impossible.
With the motor off, everything shifts fine. Not buttery, but fine.
Clutch began to have a strange pedal feel around halfway through engagement. The best explanation was the engagement was not consistent.
Shop claimed it was a tranny issue, so I decided to pull it. My initial guess was pilot bearing or slave cylinder.
Tranny was interesting to pull. The shifter was a PITA and Kooks 1 7/8 makes tranny pulls VERY tough. It limits how much the motor can angle to get the bellhousing bolts and the bellhousing will not come off around without loosening the drivers side header. So once we tore it all apart, this is what we found:
The bolts and the holes do not allign for removal. Additionally, it is hard to see from the pictures, but the flywheel is not square to the pressure plate. There is a larger gap at the bottom than at the top.
Has anyone ever seen this?
10-20-2012, 02:24 PM
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Flywheel failure is guaranteed with the stockers in these cars. Most of us just bite the bullet and go aftermarket. The LS7 clutch is popular, I'd recomend the ls9x from katech with the single mass 12lb flywheel that I have. Buttery smooth and problem free after 10k. I would look into shifter bushings and a new trans mount from cs to solve some of the shifter slop.
10-20-2012, 08:54 PM
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You can get a pry bar and line up the holes to get the bolts out. I had to do that when I changed the clutch/flywheel in my car. They all fail, it's just a matter of time. Mine was like that with 65k on it.
10-20-2012, 10:53 PM
#4
You are probably going to have to cut the outer portion off to get to the bolts. I would not suggest anything lighter than the 26 lb flywheel if you are going with a larger cam in the future. People have had issues with keeping them idling as there is no inertial force in the flywheel. Just saying.
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10-22-2012, 02:47 PM
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So the car is back together. Hardest tranny swap in my life and I have done plenty. Every little thing was a hang up:
Header flange bolts were siezed, had to cut it off by spinning the bolt with an impact and hold a saw blade to cut it.
Shifter was a **** to remove, easily took 2 hours.
Bellhousing wouldnt get past the kooks headers, had to remove the drivers side header. It was still a pita even when it was loose.
We had to cut the flywheel to remove it.
Pilot bearing took almost 2 hours, we had to grind the puller numerous times.
Everything went back together ok. Put the LS7 in with a remote bleeder. That was a must. All in all, we expected to be done in 4-6 hours.... took the entire weekend and numerous trips to the store. Almost a 12-15 hour job, and this isnt my first rodeo.
Runs great now. Clutch has a little more play at the top than I would like, but it does engage near the floor which I like (I guess sometimes you cant have both). I will post pictures of the aftermath of the flywheel.
Header flange bolts were siezed, had to cut it off by spinning the bolt with an impact and hold a saw blade to cut it.
Shifter was a **** to remove, easily took 2 hours.
Bellhousing wouldnt get past the kooks headers, had to remove the drivers side header. It was still a pita even when it was loose.
We had to cut the flywheel to remove it.
Pilot bearing took almost 2 hours, we had to grind the puller numerous times.
Everything went back together ok. Put the LS7 in with a remote bleeder. That was a must. All in all, we expected to be done in 4-6 hours.... took the entire weekend and numerous trips to the store. Almost a 12-15 hour job, and this isnt my first rodeo.
Runs great now. Clutch has a little more play at the top than I would like, but it does engage near the floor which I like (I guess sometimes you cant have both). I will post pictures of the aftermath of the flywheel.
