C4 Corvette 4+3 manual, Garbage or just different?

[Clubber_Lang]

I'm sensing I may be getting myself in trouble with an old Corvette for sale I'm considering.
It is equipped with the "Doug Nash" 4+3 manual gearbox. Im trying to learn about it, and it seems to be an odd duck to say the least. This manual was offered by GM in Vettes from 1984-1988. It used the proven Four Speed Manual coupled with an automatic(!) which could give you a total of 7 forward gear ratios, although I've heard most guys just left it off until they were on the highway, flipped the switch in 4th gear, essentially using it as a 4+1...Anyway, Ive read different accounts advising the transmissions are anywhere from total junk to pretty neat as long as maintained by the book. Thing is, Ive read that many people did not change the auto OD mercon fluid and filter out of ignorance, causing failures. There is also controversy on how to shift into OD, whether to flip the switch with the clutch in or out...

I have the chance to purchase a low mileage example (relatively) cheap. It works ok, but the service history is unknown. Id like some experienced opinions on this gearbox, how hard it is to service, and if I should just walk away from this car with its "oddity" conglomeration of a transmission ....

 

[Lyman]

Had a co-worker that bought one new. He ended up hating it after a few years. Said it was the biggest pain in the rear he had ever owned. If I were in your shoes I'd steer clear. I have heard other stories of people that hated them.

 

[DoubleWasp]

The transmission equivalent of turning the ladder to unscrew a light bulb.

Just get one with the ZF 6 - speed, and leave that notch old garbage for the die-hards.

 

[CarbonSteel]

Originally Posted By: DoubleWasp
Just get one with the ZF 6 - speed, and leave that notch old garbage for the die-hards.
x 1000 - I had 3 different C4s (1989, 1991, 1996) and all had the ZF6, never had any issues and I wish I would have kept the 1996 LT4.

 

[ls1mike]

Ah the Doug Nash 4+3...poop.

Skip it.
Spend a few more bucks, find a newer C4 if you want a C4.

 

[ragtoplvr]

These corvettes represent a good value for one to drive not race.

The first 2 years were worse. They can be rebuilt and made more reliable. That does cost up to $2000 if you r&r.

The typical lower selling price more than takes this into account.

So if you can wrench it is a good deal. If you rely on someone else, better make sure they are experienced.

Rod

 

[Clubber_Lang]

For those who are interested, here is the car in question...even though I have pretty much decided to pass.
http://www.ebay.com/itm/271868360456?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

[DoubleWasp]

Originally Posted By: 2010_FX4
Originally Posted By: DoubleWasp
Just get one with the ZF 6 - speed, and leave that notch old garbage for the die-hards.
x 1000 - I had 3 different C4s (1989, 1991, 1996) and all had the ZF6, never had any issues and I wish I would have kept the 1996 LT4.


I'd love to get the whole LT4 top end with covers for my Roadmaster LT1. Very sexy. Cam wouldn't work for me,,but the rest would look and perform awesome.

 

[Patman]

IMO the C4 Corvettes should just be avoided entirely, the C5 and newer are so much better in so many ways that it makes these cars look and feel like dinosaurs. I owned an 84 Corvette and it was nothing but trouble, and even a Toyota Camry would beat it in the quarter mile these days.

 

[A_Harman]

I had one in my '85, and suffered with it for 20 years. I had it rebuilt once, and never had a problem with it from a reliability standpoint. The things that made me get rid of it were the notchy feel of the shifter in the base T10 4-speed, and the oil pan gasket on the OD unit that just could not be kept from leaking. I replaced it with a Richmond ROD 6-speed with the racing overdrive ratio.

I took the 4+3 to a local metal recycling yard and threw it away. Even the Corvette restorers don't want to mess with them.

 

[GMBoy]

I am in the minority in that I love C4's. They get a bad rap but when you consider the time frame they were developed (80's) and how they continously improved right up to the last year- you have to give some respect. I own a 1994 and a 2003. The C4 outhandles it. Noise and comfort is better in the C5 - but the C4 has character if you will.

 

[ls1mike]

I like them too. I loved my 91, just don't like the 4+3.

 

[DoubleWasp]

The 2 areas the C4 really suffered were in interior quality (there was none) and in ride quality. I'd love to pick myself up a C4 ZR1.