ADVICE ON 1989 ZF6 TRANSMISSIONS

[EOLIVER]

I'm considering purchasing a midnight blue 1989 convertible with a ZF6. The car has 81,000 miles on it and the history in unclear. I'm contemplating buying it and having the cluth replaced to ensure a long life. How reliable is this transmission and clutch design? I'm thinking that with the mileage, I will need to replace the clutch in about 20K miles as part of regualr maintenance. What do other ZF6 owners think?

Ed Oliver
current owner of a 1987, black metalic rose coupe

 

[B17Crew]

I’ve put about 90,000 miles on former ZF equipped C4’s I have owned. My LT4 (current C4) has 51,000 miles, not one problem.

I did have to replace the clutch on one of my earlier ZF cars because I visited the track often. New clutch, master, and slave cylinder at 50,000 miles on that one. Think it ran me about $1,200.00 for everything.

As far as reliability, the ZF is rugged, although you can expect a shorter than average clutch life if you run your car hard.

B17Crew
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[jwilliams]

I have an 89 with a zf, car has 129,000 miles. It's used by me strictly for autocross. ZF is pretty bulletproof. Stock dualmass flywheels are expensive and generally can't be resurfaced. You can also go to a lighter single piece flywheel and clutch. This will help throttle response. I say go for it.

 

[MBDiagMan]

If you are such a crazy driver that you need to replace the clutch every 20K miles, I think you need to reevaluate your life.

If you have any manual transmission skill AT ALL, you will get clutch life as least as good as the previous posters.

If driven with any care and skill at all, the ZF and its clutch will prove extremely robust. For a driver that is wild and has no manual transmission skill, the only transmission and clutch that will hold up under him is found in a Mack truck.

Good luck,

 

[EOLIVER]

Thanks for the reply DOC. I'm pretty easy on my cars. I just meant that given the comments from all the postings (and the opinion of my current mechanic) that because the car currently has 81K miles on it and cluthches typically last until 100K, I should maybe go ahead and have the clutch replaced now.

 

[MBDiagMan]

Thanks for the reply DOC. I'm pretty easy on my cars. I just meant that given the comments from all the postings (and the opinion of my current mechanic) that because the car currently has 81K miles on it and cluthches typically last until 100K, I should maybe go ahead and have the clutch replaced now.

To begin with I went back and reread my post and I'm glad you didn't take it the wrong way. I should not have said "If YOU drive..." I should have said "If a person drives..." I was not making an insinuation about YOUR driving, I was only trying to make a point.

Now, as far as replacing the clutch, if it ain't broke, don't fix it. Drive it and see how it does. If it slips or chatters, then replace it, but not until then. I have a German sedan with a five speed that I thought about replacing the clutch about 7 years ago because it was chattering just a tad. I bought everything and then the chattering went away. The clutch and stuff are still on the shelf in the shop and the clutch in the car is still doing fine. Since that time I've put about 180,000 miles on the car, granted they are highway miles but still, the clutch job would have been a waste of time.

If the clutch is okay for now, take that clutch money and replace all the fluids and check the brakes. Whenever I buy a used car I always go through it replacing all the fluids INCLUDING the brake and clutch fluid flushing. It will be money and time spent well in the long run.

Did you get the car yet? It sounds like a really nice car. I would love to have a six speed convertible.

Enjoy,

 

[EOLIVER]

Well test drove the car today and loved it. The gears are really close together and I'm going to have to install a CAG plug. Nothing but pure fun. Thanks everyone for you honest opinions.

 

[MBDiagMan]

Yep, this is a car that I think you will enjoy IMMENSELY. A convertible AND a six speed, WOW!

BTW, I noticed that you are in the Navy. We appreciate your service to our great country.

Good luck,
Larry Bible
E-5 US Army
1968 to 1971

 

[EOLIVER]

I too thank you Larry for your service, many never serve at all and don't realize what a great country this is despite its own problems. Larry. I just retired after 21 years. Thanks for the opinion and I will post some pictures soon.

Ed Oliver
W3
1984 - 2005

 

[MBDiagMan]

Congratulations on your retirement. When I was in the Army was at its lowest point. Even so, there have been many times when I wish I had stayed in until retirement. I had a chance to go to Warrant Officers school and did not take it.

I was 22 when I got out and I did not realize that getting out at 39 would not have been too late for a whole new career. Oh well hind sight is always 20/20.

Enjoy your retirement and your new toy,

 

[Vettefan87]

If you are such a crazy driver that you need to replace the clutch every 20K miles, I think you need to reevaluate your life.

That is kind of harsh .

Depending on how you drive, between tracking the car, autocrossing the car, racing you can go through clutches very easily, oh well Corvette's are made to be driven hard.

 

[MBDiagMan]

AGAIN vettefan87. If you know how to handle a manual transmission you can go as fast as anyone without abusing your equipment.

Go watch the old veteran race drivers. The ones that are near retirement. They typically drive so smooth that you think they aren't going fast, but in reality they are running off and hiding from most everyone.

Be patient kid, you'll learn how to drive smooth, fast and be easy on your equipment. It just takes time.

Have a great day,