Embrace or Avoid ZF6 LT1 ?
#1
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Embrace or Avoid ZF6 LT1 ?
I'm new here and on the verge of buying a '95 ZF6 LT1. I've been reading post after post about issues with the lack of DMFs, rattling and obsolete parts (pivot) when it comes time to replacing the clutch. The car I am considering is stock and runs fine now with 80k miles but I feel like I'll be dealing with this issue in the not so distant future given the mileage. My question is, can I dive in and be excited about the 6 speed or would it be smarter to look for an automatic car?
Thanks,
Scott
Thanks,
Scott
#2
You’re correct in that you can’t get DMF flywheels new on the shelf, but they’re not made of glass either. They do last. 80k on a solid driving car I’d expect a lot of life left in it. When it does fail you have options, you’re not dead in the water. There’s single mass conversions, used tested good DMFs, and the rare popup of a new DMF that someone kept as a spare and no longer had a need for it.
My 94 has 115k, I’ve had no issues with DMF or the pivot ball. A more common fail point is the clutch hydraulics and that is a matter of when, not if. As easy as they are to replace the quality of off the shelf parts can lead to a world of headaches. Safest bet seems to be to have the original cylinders refurbished and skip the foreign made reproductions.
My 94 has 115k, I’ve had no issues with DMF or the pivot ball. A more common fail point is the clutch hydraulics and that is a matter of when, not if. As easy as they are to replace the quality of off the shelf parts can lead to a world of headaches. Safest bet seems to be to have the original cylinders refurbished and skip the foreign made reproductions.
#4
Team Owner
Pro Mechanic
Dive in. Get excited. I've had mine for 9 years...only changed the oil...car has 183k on it and I USE it; drag track, road trips, road course, auto-x. Anything is going to have issues eventually....find a solution then.
.
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Last edited by Tom400CFI; 05-22-2018 at 01:32 PM.
#5
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Great info guys, I think that's just the nudge I needed. 6 speed was the one major 'want' when I started looking.
Will post here if/when the deal goes through.
Thanks,
Scott
Will post here if/when the deal goes through.
Thanks,
Scott
#6
Melting Slicks
Enjoy!
FYI- I reused my DMF at 105k miles. I cleaned it up with a maroon scotch brite pad, and put it back into service with a stock clutch kit from carolina clutch. Im around 127k miles now, rock solid. Just the usual ZF click/clack here and there.
Have fun!
FYI- I reused my DMF at 105k miles. I cleaned it up with a maroon scotch brite pad, and put it back into service with a stock clutch kit from carolina clutch. Im around 127k miles now, rock solid. Just the usual ZF click/clack here and there.
Have fun!
#7
Race Director
The heavy dual mass flywheel is a design flaw.
Fix the noise at its source with a thicker countershaft shim and get rid of that POS (use it as an anchor for your boat).
Use a sprung hub clutch and install a lighter single mass flywheel when it comes time to do a clutch change
Fix the noise at its source with a thicker countershaft shim and get rid of that POS (use it as an anchor for your boat).
Use a sprung hub clutch and install a lighter single mass flywheel when it comes time to do a clutch change
#8
Melting Slicks
The heavy dual mass flywheel is a design flaw.
Fix the noise at its source with a thicker countershaft shim and get rid of that POS (use it as an anchor for your boat).
Use a sprung hub clutch and install a lighter single mass flywheel when it comes time to do a clutch change
Fix the noise at its source with a thicker countershaft shim and get rid of that POS (use it as an anchor for your boat).
Use a sprung hub clutch and install a lighter single mass flywheel when it comes time to do a clutch change
#9
Safety Car
#10
Melting Slicks
Both my Corvettes have been 1995 LT1 6-speed cars. Love them both. Go for it.
Has this car been abused or raced? Owned by a teenager? I don't see any reason to suspect the clutch will go out soon. Yes, if you own it long enough, it will eventually need to be replaced. But in normal driving the only time it really slips much is starting up hills. On flat ground, there's only a tiny tiny bit of slip starting out in first gear. If everything is in good condition, it will only need maintenance. Occasionally things will break or fail, just due to the age of the cars. But I personally have not had any issues with either of mine. 1995 and 1996 are the very best years of the C4 generation.
Has this car been abused or raced? Owned by a teenager? I don't see any reason to suspect the clutch will go out soon. Yes, if you own it long enough, it will eventually need to be replaced. But in normal driving the only time it really slips much is starting up hills. On flat ground, there's only a tiny tiny bit of slip starting out in first gear. If everything is in good condition, it will only need maintenance. Occasionally things will break or fail, just due to the age of the cars. But I personally have not had any issues with either of mine. 1995 and 1996 are the very best years of the C4 generation.
#12
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St. Jude Donor '16
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My first question is how will you use the car? daily or second fun car?
I drive both and would rather drive the 6 speed just more fun and a better driving experience.
I only drive my 95 LT1 auto if I have to go into Atlanta and spend hours in the traffic.
I drive both and would rather drive the 6 speed just more fun and a better driving experience.
I only drive my 95 LT1 auto if I have to go into Atlanta and spend hours in the traffic.
#13
Le Mans Master
Another vote for jump in and get it.
I have had two '94's, a '95, and a '96 with ZF 6 speeds. They are very good. They are reliable and strong. If the clutch/flywheel go bad at some point there are single mass replacements if you can not use the dual mass.
I have run up to 145k on the original stock clutch/flywheel and it was still good when I sold it (on my white '94). I have also changed the flywheel and clutch on my '96. I put in a used set from a stock '90. That set looked brand new and is working perfectly.
As for the driveability of a C4 with the 6 speed, LOVE IT. It is a good setup for a driver's car. It is fun working through the gears or selecting the right gear while on the twisty roads. As a side benefit, the overdrive 6th gear is a 0.50 ratio so highway cruise is at low rpm. The result is they get about 30 mpg on a highway cruise where the automatics get 4 or 5 mpg less.
In short they are great. That is why I have had 4 of them and still have the '95 and '96.
Good luck.
I have had two '94's, a '95, and a '96 with ZF 6 speeds. They are very good. They are reliable and strong. If the clutch/flywheel go bad at some point there are single mass replacements if you can not use the dual mass.
I have run up to 145k on the original stock clutch/flywheel and it was still good when I sold it (on my white '94). I have also changed the flywheel and clutch on my '96. I put in a used set from a stock '90. That set looked brand new and is working perfectly.
As for the driveability of a C4 with the 6 speed, LOVE IT. It is a good setup for a driver's car. It is fun working through the gears or selecting the right gear while on the twisty roads. As a side benefit, the overdrive 6th gear is a 0.50 ratio so highway cruise is at low rpm. The result is they get about 30 mpg on a highway cruise where the automatics get 4 or 5 mpg less.
In short they are great. That is why I have had 4 of them and still have the '95 and '96.
Good luck.
#14
Le Mans Master
I really wouldn't worry about it.
#15
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St. Jude Donor '05
Get it in high gear and floor it if it isnt slipping, gears arent crunching dont sweat it. dont settle either youll regret it.
A clutch isnt very much, a simple LUK is all you need.
A clutch isnt very much, a simple LUK is all you need.
#16
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After reading these responses, I felt fine with going for it and did. I ended up with a different car that has already had the clutch done. So glad I went this way.
Thanks for the encouragement...
Scott
Thanks for the encouragement...
Scott
Last edited by C4SP; 06-25-2018 at 05:30 PM.