What Trans? TKO,T5Z,T56 ?

TwoToneHatch

Active Member
Mar 22, 2007
170
2
28
New Jersey
Alright guys my daily driver '89 GT is a stock longblock bolt on car that runs in the 13's. I broke a regular T5 and went with a G-Force T5 and it was nothing but problems so now I'm in the market for a new transmission. I'd rather not have to go with another T5 and I'm against any "built" T5's . So does anyone have any first hand experience with a TKO500/600 or T56 in a fox? My plans are h/c/i and eventually a blower. I want a trans that will be able to be driven everyday and take a beating .
 
Forgot to add, if it sees a lot of track time you'll obviously want to pay attention to gear ratios if you're trying to keep the car consistent with what it was. I believe one of the TKOs has a pretty steep 1st
 
I have a TKO-600. Hopefully in a couple of weeks I can tell you how nice it is. Until then I would still have to recommend a TKO instead of a T56. When I was at the transmission crossroads, I realized that I wouldn't be running a lot of gear (3.55's), so I didn't really need the second OD. Plus the T56 is more expensive and heavier. If you were going to be running a lot of gear (4.10's or higher) and were going to be on the highway a lot. Then I would recommend one, otherwise IMO, I feel it is a waste.
 
I had a T-56 a while back, it was definitely heavy and the one I had had the close ratio gears and just 1 OD. If I had known it only had 1 OD when I got it I would have gotten the right one but I wans't offered any options when I ordered it. Strength wise it held up when T-5's didn't but I think next time I'll do a TKO though.
 
I have a TKO-600. Hopefully in a couple of weeks I can tell you how nice it is. Until then I would still have to recommend a TKO instead of a T56. When I was at the transmission crossroads, I realized that I wouldn't be running a lot of gear (3.55's), so I didn't really need the second OD. Plus the T56 is more expensive and heavier. If you were going to be running a lot of gear (4.10's or higher) and were going to be on the highway a lot. Then I would recommend one, otherwise IMO, I feel it is a waste.

Definitely let me know how it treats you. I would just bite the bullet and order a TKO but I keep hearing of shift gate issues which is why i'm considering a T56. I only run 3:73's so i don't have to much gear.
 
Definitely let me know how it treats you. I would just bite the bullet and order a TKO but I keep hearing of shift gate issues which is why i'm considering a T56. I only run 3:73's so i don't have to much gear.

Do a search and you should find posts by uses of TKO's on this forum who are pretty happy with them. Some still post here, so they might see this thread and post in it.
 
I plan on getting a TKO 600. From what I've heard about a t56 in a fox is it leaves little room for exhaust, and as stated above, very heavy.

When I first decided on the tko I wanted the 500 because you can get it with a stupid deep 1st gear. I called promotion and they told me I didn't want that, everyone who buys it decides first gear is too low and calls back wanting to trade it in on a 600.

They offer two different od ratios-.82 for road racing and .64 for street.

They offer 10 spline (stock style) and 26 spline input shafts. The 26 spline is stronger.

For $100 extra, promotion will tear down the new tko before shipping it to you, blueprint it, properly setting clearances, and deburr and polish the dogs so it engages slicker. Tko's have a reputation for being notchy, and supposedly, this fixes it.

Personally, I'd go with a 26 spl .64 od tko600.

My .02.....
 
I don't think you can get a 600 with a 10 spline input shaft. I was under the impression that was 500's only, although i could be wrong.
For anything other than a dedicated road race car, you need the .64 5th gear.
I have a promotion tko600, and i wouldn't trade it for any trans.

The t56 is an expensive novelty. The base models aren't that strong and the swap costs more. No justification in it. People will try and make the argument that the 6th gear in a t56 provides more gas mileage, but an 03 cobra t56 is a .63. Not exactly a big change.

The tko is also very versitile. I've used mine for years with pushrods, then got a new bellhousing and use it with my 03 cobra engine, same clutch too, just got a new flywheel drilled for 10.5 and 11.
 
I don't think you can get a 600 with a 10 spline input shaft. I was under the impression that was 500's only, although i could be wrong.

Nope. You are correct. the 500 is the only one available with 10 spline and 26 spline. The 600 are all 26. My mistake.
 
People will try and make the argument that the 6th gear in a t56 provides more gas mileage, but an 03 cobra t56 is a .63. Not exactly a big change.

A friend of mine had an 02 Z28 with a factory T56 in it with the .50 6th. He told me it was a total waste as it would lug in 6th @ 75mph with 3.42 gears. So even if the OD was steeper it isn't all that useful. Like I said, if you plan to run 4.10's or 4.30's with it, then it probably is worth it.
 
A friend of mine had an 02 Z28 with a factory T56 in it with the .50 6th. He told me it was a total waste as it would lug in 6th @ 75mph with 3.42 gears. So even if the OD was steeper it isn't all that useful. Like I said, if you plan to run 4.10's or 4.30's with it, then it probably is worth it.

I had a 94 Z28 and it also had the .50 6th gear. It lugged also under 75 but did just fine over 100mph.(or 110, 120,130,140...) They made around 300 hp... a 3:73 or 4:10 gear and/or more hp would have been nifty.
 
I find the newer TKO600 to not be notchy....TKO600 or MMR TKO 900 gets my vote depending on the power you planto make.

I'm looking to DD my car with a 12 second h/c/i combo and then throw a blower on it when i can make it the weekend car. I want to spend the money once so I want something totally strong while i have the chance. Will a TKO be able to be driven on everyday?
 
I'm looking to DD my car with a 12 second h/c/i combo and then throw a blower on it when i can make it the weekend car. I want to spend the money once so I want something totally strong while i have the chance. Will a TKO be able to be driven on everyday?

Yes, after a couple days with a tko you forget what a t5 felt like.
Would i say the t5 is smoother? Probably, but it's like a heavy clutch, you get used to it.
 
I drove my car daily for 2 years with the TKO in it. Then the transmission was used for 2 summers with a HCI/novi 2k combo, then 1.5 summers with the current motor before i had to have it rebuilt. It had a few minor problems, and a blown 3rd gear synchro. Its faceplatted now, so no more synchros to worry about
 
I had a 94 Z28 and it also had the .50 6th gear. It lugged also under 75 but did just fine over 100mph.(or 110, 120,130,140...) They made around 300 hp... a 3:73 or 4:10 gear and/or more hp would have been nifty.


Both of my GTO's had 6 speeds. While IDK what the 6th gear ratio was, but I constantly drove that thing in 6th while going anything over 65. It had a 3.73 rear and it was perfecto, amigo.