dizwiz24

Is it a lot of work to swap the lighter, more durable t56 in place of the ZF? 93 c4?

One day if I need to replace my transmission thats the route im going to go.

jhammons01

When you get to that point.....post that you would like to trade a ZF for a Tremec....and watch a line of Tremec guys form up in front of you hoping to get that ZF....LOL

93VettePilot

Not likely. The T56's were used on Vipers and are a very strong, smooth shifting, quiet, and light weight tranny. The T56's are pretty pricy at junkyards. Sometimes they go for $1200.

Dizwiz, I've never done the swap but you would need the bellhousing from an Fbody, Custom Driveshaft, and have to fabricate some mounts. I'm pretty sure you would need the clutch slave and master from an Fbody too.

DVNCI

Don't forget the shifter in the ZF is offset - it does not come up in the same spot a T56 does.

I don't "think" it's enough of a difference to matter all that much in a swap (I know the LSX swaps w/ T56 seem to work fine) but something to consider.

tpi 421 vette

Hi Dave, If you want a stronger trans, consider getting a black tag ZF. The earlier ones, 89-92ish. It seems like 1993 is either way. I am not sure of the exact date they switched to the later blue tag. But if you have the blue tag, there is room for improvement. I have been putting 800rw ft/lbs or torque thru my black tag for years, and never had problems. They are noisier than the later ones due to their closer to a straight cut gear, which gives you more contact area. And a ZF has a 32 spline output shaft (same as a TH400), a standard T56 has a 27 spline output shaft, which I have seen many either twist or completely snap in two. And a Viper spec T56 has a 30 spline output shaft. And the black tag is a bolt in. Except it uses a different t.o. bearing from the blue tag you have, which is bigger.

The Germans lost the war...but build a hell of a tranny!

rklessdriver

The T56 used in the Viper ain't the same as the one GM installed in the F body. It takes close to $1000 in internal parts to upgrade a GM factory one to the point of being worth a crap.

I've busted the input and countershaft teeth on a few stock T56's just by dumping a good clutch too hard on LT1/LSX F Bodies with slicks and a real rearend. The craptastic 10 bolt rear end is the only reason the T56 lives behind even mildly modded F Bodies....

Now all you guys with 300RWHP and street tires will never know the difference but if you've got a real motor and some traction that junkyard T56 is going to be headed back to where it came from - in a hurry.

Why spend all that $$$ when a ZF6 is near indestructable.
Will

jhammons01

^^LOL......nuff said..

Craptastic....LOL

Is there a line formed yet OP??

93VettePilot

My Fbody had a Moser 9", Street Twin Clutch, and a 700hp blower motor and the 130,000 mile T56 held up fine. Not trying to start a flame war but if you check around you will see literally hundreds of Fbody's in the 9's on a T56.

I don't think it is worth it to do a swap because the ZF6 is a great transmission too. It is not really an "upgrade" so all the hassle would not be worth it IMHO.

v8vette84

I COMPLETELY disagree that the T-56 is crap... I have one in my Camaro and it takes a beating. Never seen one get destroyed/break and i have one particular friend who runs a 95' Camaro 355 LT1 TT. 12 bolt rear and runs easy sub 11's. Never had a T-56 break on him.... idk where ppl get the fact that T-56's are weak. Not anywhere close.... the only thing i have against the ZF-6 is the cost to rebuild it, I hear they are quite pricey....

rogerdoger1993

I had to chime in on this thread when I saw it. I had a ZF6 black tag in my 93 that was starting to get notchy shifty symptoms. So instead of trying to rebuild it I just bought a brand new one on fleabay. The cost of a rebuild was going to be around $1800. Whereas a brand new one delivered to my front door costed exactly $1,100. Do the math.

STEVEN13

Hi,

Are you guys power-shifting your ZFs? If yes, are you on sticky tires?

Thanks,
Steve

v8vette84

I can pick up a T-56 around here for 500-1000 bucks. I'm actually going to get one for $900 next week.... I think the ZF and T-56 are both great transmissions. Both GM designed...

rklessdriver

Sometimes and Yes.

The ZF is not a Jerico DR4 or anything - but it is fairly easy to powershift - if you know what your doing... however that is NOT the fast way to shift one. I prefer to "bump" the clutch, just a little bit...
Will

cv67

Seems the hydraulics can limit powershifting if any fluid bypasses the Oring inside the slave. Have experienced that with both the ZF and T56 Hrdraulics. For some reason normal use or a quick shift is fine, stabbing the pedal doesnt always seem to work out right.
Not worth the risk of damaging a trans for maybe a tenth?

mnstrlt1

bill (zfdoc.com) showed me the difference in the internals of the t-56 and the ZF. there is a reason why the ZF weighs more! the Black tag 6-speeds are monsters!

the technology used in the ZF is actually superior to the t-56. Don't get me wrong, I'm a huge fan of the t-56 in particular applications. The new t-6060's are starting to show similar (equivalent) materials and technology used in the ZF's...

long story short, I'd stick with the ZF>

McGirk94LT1

Not that im an expert on either but just use whats around you to make an informed judgement call. It all comes down to you hear some bad experiences mixed in with the good about the t-56. I personally have never heard any real complaints about the black tag zf-6.

shadowskill

Man I've got a T56 that just swapped to my LS1 Z28: lightweight flywheel, agressive dual sided clutch, mgw shifter and all. For sure I know the T56 can take a beating. With the Z28 on long term repairs (slippery road on rain, too much torque, no TCS, but thats another story) I just considered to put the T56 on my A4 C4 wich I'm tired to road race on (cannot shift it manually without heating up everything), and, believe me, it's not a short route.

You'll need the c-beam t56 adapter kit, lt1 to t56 bellhousing, shifter will have a 2-3inch offset to the right (or cannot use your favorite short shifter combo), will have to adapt new hydraulics, will have to work on tunnel and center console adjustments (a lot of dremel work) and may have to also adjust clutch coupling issues.

As durability, I think the ZF6 will outlast a T56, but I can't personally confirm that. I would just ditch weight elsewhere, a black tag ZF is worth it. D44 & ZF6 will get you fast around a corner, no problem: thats just the ideal upgrade on our C4s for lots of us.

bill mcdonald

T56 in my stock Z06 lasted 75K miles.