TPIMarow6.6

I was just wondering why people dont swap ZF 6-speeds into there cars? iv seen them on 89-92 TPI corvettes and some ZR1's. is there a reason why people dont use this transmission, sorry i dont know alot about these but i was wondering if someone did, i know they probably dont have the torque arm bar mount but besides that whats different?

89 Iroc Z

The T-56 swap is a lot easier to install and are cheaper. I always liked the ZF but it's a lot of work. You will need to fabricate a cross member and a torque arm mount. Also the ZF will hit the console in 1'st gear so you will need to fabricate a custom center console.

TPIMarow6.6

that doesnt actually seem like alot of work, you can always get a torque arm relocation kit and the consol, thats not a major job, but what about flywheels, clutch hydraulics ect? are all of that different or different then the 5-speed clutch setups....

IROCZZ3

Do a search for ZBRA...he used to have a sweet Z28 with a ZF 6 speed he installed.

It's definitely not as easy as putting in a T56.

TPIMarow6.6

alright a few questions i had, was about the speedo cable and cost.... ect.

jmd

iTrader: (4)

https://www.thirdgen.org/techbb2/sho...hreadid=237455

read my post there.

TPIMarow6.6

Thanks!

cam-

Another nasty issue with the ZF is they use a bolt on yoke not a slip yoke and there is only a couple of inches of spline so using one with a slip yoke is precarious to say the least.

rx7speed

what is the real difference between the ZF and the T-56

why would someone even want the ZF

Parrydise7

iTrader: (1)

German engineering, German craftsmanship and, IIRC, some Firehawks came from the factory with the ZF. GM must have thought pretty highly of it if they put it in some third gens and Corvettes.

Again, IIRC, some Chevy trucks also came with the ZF.

884+3

I installed a ZF in a 64 nova behind a big block 402 a few years ago and just recently began driving it on a regular basis. The ZF has a tendency to knock like an engine bearing about to launch through the oil pan. If you dont use the corvette dual mass flywheel they have the knocking noise. The noise isnt supposed to hurt anything but it is annoying idling below 1000 rpms.

jmd

iTrader: (4)

Yeah, but not the same box from ZF as the 89-96 C4 had.

884+3

Here is more info on the noise i was refering to in my first reply. This came from Corvette Centrals 84 to 96 parts catalog.

rx7speed

what is this 4+3 tranny?

cam-

The 4+3 was made by Doug Nash who has a wicked rep for building tough racing trannies but the 4+3 was not one of his career highlights to say the least. I don't know how strong they were but it had an electric actuated overdrive that you could use from second on up hence the 4+3 name. I wouldn't waste my time ever trying to swap one thats for sure. Anyone know the actual torque rating these things had?

nsimmons

it was a super t-10 with an overdrive. So a decent tranny, just a touchy over drive unit, usual problems were related to switches after 15+ years, and lack of care.

A good idea in theory, there were revisions to rebuild kits to fix common problems.