2000 M6 FRC With horrible drivetrain vibration
10-24-2018, 10:55 PM
#1
Heel & Toe
Thread Starter
Member Since: Oct 2018
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
2000 M6 FRC With horrible drivetrain vibration
Ok so here’s the story. Bought a car with some issues for what I thought was a good deal. 🤦🏻*♂️ The car has two main issues I need help with over anything.
Heres a break down of the car.
Prc heads 1.5
btr stg 2 cam
fast 90
200 kit on top tuned for spray
the seller says he took the car to the track and started having these issues then.
When the car is idling there’s no vibration but wether it’s in gear or not clutch engaged or not once it gets about 1800+ rpms the entire vehicle starts vibrating like crazy not much different in gears and driving ether.
Another jssue is he said the car wouldn’t go into 5 or 6. The shifter wouldn’t even push over. During the test drive I went to go into 5 (habit) and it grounded a second first (then I thought o yea) tried again then it went into gear and pulled under load.
Alsoooooo the clutch as I move it around the yard and in the garage I’ve noticed a reddish fluid drip looking like it’s coming from the clutch area and when using the clutch moving around as stated the clutch gets to have no pressure to active the clutch.
PLEASE HELP 🤦🏻*♂️🤦🏻*♂️🤦🏻*♂️
Heres a break down of the car.
Prc heads 1.5
btr stg 2 cam
fast 90
200 kit on top tuned for spray
the seller says he took the car to the track and started having these issues then.
When the car is idling there’s no vibration but wether it’s in gear or not clutch engaged or not once it gets about 1800+ rpms the entire vehicle starts vibrating like crazy not much different in gears and driving ether.
Another jssue is he said the car wouldn’t go into 5 or 6. The shifter wouldn’t even push over. During the test drive I went to go into 5 (habit) and it grounded a second first (then I thought o yea) tried again then it went into gear and pulled under load.
Alsoooooo the clutch as I move it around the yard and in the garage I’ve noticed a reddish fluid drip looking like it’s coming from the clutch area and when using the clutch moving around as stated the clutch gets to have no pressure to active the clutch.
PLEASE HELP 🤦🏻*♂️🤦🏻*♂️🤦🏻*♂️
10-25-2018, 01:04 PM
#2
Check engine mounts, harmonic balancer. If it's not either of those, could be a flywheel/pressure plate imbalance, but that seems less likely since it should've been there the whole time, and won't just spontaneously happen after going to the track...but it depends how much you trust the word of the guy who sold it to you. There are no red fluids in the engine bay of a manual C5 unless somebody topped off the power steering fluid with ATF. Sounds like you'll be dropping the drivetrain anyway, so you can investigate then. Good luck.
10-25-2018, 02:10 PM
#3
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
Received 2,180 Likes
on
1,583 Posts
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If I had to guess, (and its a pretty good guess) I would say you have a shredded Torque Tube (TT) rubber coupler.
The 2000 has the smaller diameter rubber couplers and they get old and crack and if used hard (200HP SPRAY LOL! ) they pop! It will look like a rats nest inside the TT!
YES, you will have to pull the drive train out to service the TT. You might as well replace the clutch disk, Pressure Plate, throw out bearing slave cylinder and the pilot bearing while you have it apart. Also add in a remote bleeder and replace the master cylinder also. It gets full of clutch dust slime and will most likely fail soon after you have all that new clutch stuff installed.
The 2000 has the smaller diameter rubber couplers and they get old and crack and if used hard (200HP SPRAY LOL! ) they pop! It will look like a rats nest inside the TT!
YES, you will have to pull the drive train out to service the TT. You might as well replace the clutch disk, Pressure Plate, throw out bearing slave cylinder and the pilot bearing while you have it apart. Also add in a remote bleeder and replace the master cylinder also. It gets full of clutch dust slime and will most likely fail soon after you have all that new clutch stuff installed.
Last edited by Bill Curlee; 10-25-2018 at 02:10 PM.
10-25-2018, 02:15 PM
#4
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
Received 2,180 Likes
on
1,583 Posts
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If it were me, I would drain and refill the transmission with new fresh ATF to see if that helps shifting. Contaminated old fluid can and will cause shifting issues. Is a cheep check. The MN6 and MN12 takes 3.75 quarts of ATF. Suppose to use DEXTRON III but you will need to find a compatible ATF.
If its never been changed it will look like dark red metal flake paint when it comes out!!!
If its never been changed it will look like dark red metal flake paint when it comes out!!!
Last edited by Bill Curlee; 10-25-2018 at 02:16 PM.
10-25-2018, 02:18 PM
#5
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
Received 2,180 Likes
on
1,583 Posts
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Can you shift into 5-6 when the engine is OFF?? Is it difficult with the engine off?
10-25-2018, 02:21 PM
#6
Heel & Toe
Thread Starter
Member Since: Oct 2018
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Haven’t checked with the engine off.
If its the torque tube couplers, why would it vibrate when the car is sitting still, while in neutral while not engaging the clutch? What’s the reason for it to be rotating at that point?
If its the torque tube couplers, why would it vibrate when the car is sitting still, while in neutral while not engaging the clutch? What’s the reason for it to be rotating at that point?
10-25-2018, 04:28 PM
#7
That's why I did not suggest the torque tube couplers as a possible culprit. If it vibrates when you rev it with the clutch pedal on the floor, the driveshaft inside the torque tube would be decoupled from the engine and not rotating, which rules it out as the source of the vibration.
10-25-2018, 10:46 PM
#8
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
Received 2,180 Likes
on
1,583 Posts
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I read "NOT ENGAGING THE CLUTCH" as you did not have it depressed. If you have the clutch DEPRESSED and engine running, then the TT Prop shaft should not ne rotating. Is that the case?
10-25-2018, 11:40 PM
#9
Team Owner
My guess is the symptoms you are experiencing are from a clutch failure but are the result of a torque tube that is worn.
I lost a spring out of the hub of the clutch disc when a torque tube was degrading but had not completely failed. It caused all sorts of vibrations and engagement/disengagement problems. We actually put a twin disk in it and it drove fine for a while no vibrations before the torque tube failed damaging a disk in the clutch.
You will have to start taking it apart and see what you find. I would take the prop shaft out of the torque tube and inspect the couplers and bearings even if you think you find the problems in the bellhousing as the torque tube maybe the origin of the problems.
If I do a clutch the torque tube gets inspected. Also if the bellhousing comes off, add a remote bleeder. It will make bleeding the system vastly easier and clean fluid will reduce chances of the infamous sticking clutch pedal.
I lost a spring out of the hub of the clutch disc when a torque tube was degrading but had not completely failed. It caused all sorts of vibrations and engagement/disengagement problems. We actually put a twin disk in it and it drove fine for a while no vibrations before the torque tube failed damaging a disk in the clutch.
You will have to start taking it apart and see what you find. I would take the prop shaft out of the torque tube and inspect the couplers and bearings even if you think you find the problems in the bellhousing as the torque tube maybe the origin of the problems.
If I do a clutch the torque tube gets inspected. Also if the bellhousing comes off, add a remote bleeder. It will make bleeding the system vastly easier and clean fluid will reduce chances of the infamous sticking clutch pedal.
Last edited by 93Polo; 10-25-2018 at 11:49 PM.
10-26-2018, 09:27 PM
#10
FWIW, when I did my clutch (paid to have 'er done, Rich @ Abel), we priced out OEM couplers + bearings + labor and found that an entire new prop shaft + labor only cost $100 more than re-using the old one.
In retrospect, I wish I waited long enough to find someone selling a carbon fiber one, used. Oh well. Next time (hopefully not for many years.)
Another interesting note: Some people go to a solid coupler instead of a rubber coupler, which is a one-and-done item (no more wearing out.) The obvious downside is that you get noticeably more drivetrain vibration due to no dampening. The other obvious downside is cost, the aluminum couplers are more expensive. The one that people seem to not know about, as per Rich @ Abel, is that the solid couplers generally need to be machined to be perfect, which can easily add an extra couple hours of machine shop time to get just right.
In retrospect, I wish I waited long enough to find someone selling a carbon fiber one, used. Oh well. Next time (hopefully not for many years.)
Another interesting note: Some people go to a solid coupler instead of a rubber coupler, which is a one-and-done item (no more wearing out.) The obvious downside is that you get noticeably more drivetrain vibration due to no dampening. The other obvious downside is cost, the aluminum couplers are more expensive. The one that people seem to not know about, as per Rich @ Abel, is that the solid couplers generally need to be machined to be perfect, which can easily add an extra couple hours of machine shop time to get just right.
10-27-2018, 10:17 AM
#12
If the clutch is dragging the drive shaft will still be spinning with the clutch pedal pressed to the floor. So vibration could still be in the torque tube. The only way to guarantee the drive shaft is not spinning is to put the car in gear and start it with the clutch held to the floor. When someone puts those mods on the car and then sells it with odd issues you might as well resign yourself to pulling the torque tube.
Last edited by jpb1978; 10-27-2018 at 10:21 AM.
10-28-2018, 02:38 AM
#14
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
Posts: 32,736
Received 2,180 Likes
on
1,583 Posts
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If the clutch is not completely disengaging it will have a negative effect on shift quality. If ANY of the synchros and or blocker rings are worn you will find it difficult to get that gear IN GEAR.
Jack the rear wheels off the ground.. Engine running, car in gear.. Clutch FULLY DEPRESSED.. See if the rear wheels stop driving OR can be stopped from rotating. If they cant,,, SOMETHING IS ROTTTEN IN THE CLUTCH..
Bill
Jack the rear wheels off the ground.. Engine running, car in gear.. Clutch FULLY DEPRESSED.. See if the rear wheels stop driving OR can be stopped from rotating. If they cant,,, SOMETHING IS ROTTTEN IN THE CLUTCH..
Bill
Last edited by Bill Curlee; 10-28-2018 at 11:56 AM.
11-02-2018, 02:02 PM
#15
Burning Brakes
If I had to guess, (and its a pretty good guess) I would say you have a shredded Torque Tube (TT) rubber coupler.
The 2000 has the smaller diameter rubber couplers and they get old and crack and if used hard (200HP SPRAY LOL! ) they pop! It will look like a rats nest inside the TT!
YES, you will have to pull the drive train out to service the TT. You might as well replace the clutch disk, Pressure Plate, throw out bearing slave cylinder and the pilot bearing while you have it apart. Also add in a remote bleeder and replace the master cylinder also. It gets full of clutch dust slime and will most likely fail soon after you have all that new clutch stuff installed.
The 2000 has the smaller diameter rubber couplers and they get old and crack and if used hard (200HP SPRAY LOL! ) they pop! It will look like a rats nest inside the TT!
YES, you will have to pull the drive train out to service the TT. You might as well replace the clutch disk, Pressure Plate, throw out bearing slave cylinder and the pilot bearing while you have it apart. Also add in a remote bleeder and replace the master cylinder also. It gets full of clutch dust slime and will most likely fail soon after you have all that new clutch stuff installed.
All that labor... what is a better upgrade? I understand there are size differences between the years and models... considering I would stick with my now rebuilt (and upgraded) M6 transmission.... what are my options... if i want a carbon one piece... and will it be adequate for 500whp-600whp (long-term). Instead of buying individual pieces, paying labor of taking it apart and putting it in, rather get for some more the whole carbon one piece and pay labor on installing that...