Can anyone tell me much of anything about the corvette ZF6? I found one for around the same price as a T56. Will it be a straightforward bolt up to a LT1 or earlier chevy v8?
Are they durable? How much power can they handle?

Sorry if this is the wrong forum, but there is no Transmission forum.

 

I don't think they are a direct bolt in....but I'm not sure. Seems like they take a different bellhousing and I know the clutches are different.

The older ZF 6-speeds (black label units) are rated at 450 ft lbs and the newer transmissions (blue label units) are rated for 400 ft lbs. I run a supercharged stroker motor and I'm installing my 4th engine this spring and I still running an untouched blue label transmission and I'm makinng about 600 ft lbs of torque. I've been looking into rebuildinng my unit and have found that a basic overhaul kit runs about $1100 bucks and only a few places sell them (very hard to find). There is only one year of GM Corvette service manual that gives rebuild info (1990 or 1991...I can't remember which one)...as the unit was not intended to be serviced by gm, the subsequent years of service manuals doesn't havve the info in them. Also, there is a special socket that will need to be fabricated in order to disassemble/re-assemble the unit. If you want to have your unit rebuilt, a basic rebuild will run your about 1800-2000 but be assured, they normally find a few gears that need replacing...that's the sticker.

Good luck on your conversion and keep us posted as to how it went.
CT

 

Pretty sure they kept using the ZF 6-speed in the Corvettes through 1996. So they must have a bellhousing and clutch that works with the LT1/Gen 2 block. But everything seems to say it is no better or worse than the B-W/Tremec T-56. The T-56 is rated 450 ft-lb, and people have taken them well beyond that level... rkrause was making over 700rwHP with a blown/nitroused LT1. George Baxter ran the T-56 to over 750HP in a 4,000# convertible, but never used anything more than a 3,500rpm clutch dump and never shifted it very hard. Buddy of mine is running mid 10's on his original 1999 T-56, and he pulls low 1.5 60-foots, 6K dumps on slicks, and bangs the shifts like no one I have ever seen. The trans was intact after 3 years of very high track useage.

As a followup, all of the above then moved on to a TH400...... .

 

Here is a link to one of the guys who rebuilds the ZF trannys.
Index

 

Hey Mike, just a FYI. I sell these at work, and they are VERY expensive. I sell the Ford guys New units for around 1800 bucks. Never even looked up a corvette one. But I can imagine they are expensive. Also have parts if you need them.

Q

 

I a not sure why you want to do this. The T56 is an excellent transmission with ratios well suited for most uses for an F-body. What's the motivation? Just 'cause it's from a Corvette doesn't mean it's better.


Rich Krause

 

Well, I found one from a 96 vette with slave cylinder, master, clutch, shifter, etc in chicago for $1200. I know Detroit Speed & Engineering put one in a 69 camaro, but looking at their install is really no help because these guys make diamonds from dungpiles. It's way over the top for any average schmoe to duplicate their work

 

heh, I know that. It was just a thought because it was different. Some people I talk to say they are nearly bulletproof, others say don't mess with them.

 

It wont "bolt right in" because the torque arm mount in backwords on a vette.

 

Hey Joe,
When did you start spraying your car?
CT

 

As soon as I get my solenoids back from NX.

 

I have a bellhousing I will sell ya

 

DS&E used a viper tranny in the "Twister"........ it's a T-56.

 

T-56 stronger than you need Same thing they run in Vipers, Z06's, etc, and I believe the only differences are a stronger input-output shaft...

 

Vipers run steel shift forks (direct replacement on the M12s, not sure about MN6s) and the ZO6s (M12s) have carbon fiber syncros.