TKOII vs T 56

Draco · #1 (**permalink**) 07-13-2003, 08:15 AM

I will be purchasing a tremec tranny. I have been cruising around in my buddy's viper lately with the T56. A nice tranny. Most cobra owners have gone with the TKO and more recently the TKO II, why are they more popular for cobras than the T56. Is it a size or weight issue? The torque capacities seem to be comparable. The first gear ratios appear to be the big difference.

Any thoughts or a couple of cents?

DRACO

aumoore · #2 (**permalink**) 07-13-2003, 10:05 AM

You need to contact Jim Pomroy about a T-56 in a High HP car. His locked up in 4th gear in his supercharged Fox body Stang. He plans to go to a TKO and you really do not need a 6 speed in a Cobra. Get a TKO or a 3550 as both will take more torque than a T-56 and cost less. You can get a .080 ratio in both as well.

Gatorac · #3 (**permalink**) 07-13-2003, 11:58 AM

Is this going in a street car or a track car?

The TKOII is trated for 475ftlbs and has the .80 5th gear.
The Ford version T-56 is rated for 450ftlbs and has the .80 fith plus the .62 sixth gear.

The t-56 is about 25lbs heavier than the TKO. The T-56 is also longer and will require modifications to the tranny crossmember to make it fit. A shorter drive shaft is also required.

The TKO and T-56 will requre different clutch disks as the T-56 has the 10 spline input shaft.

I am repairing my T-56 right now. The 3rd/4th synchro is f'd up. The cost of parts alone is over $500. For $290 the dang input shaft is apperantly made out of gold... I hope I can get the parts here soon before I forget how to put it back together.

I have heard that for racing, the t-56 may not be the best choice. It is nice to have that extra gear between 4th and 5th though.

Draco · #4 (**permalink**) 07-13-2003, 01:14 PM

Its going in a street car with about 430 hp and 450 tq

Cal Metal · #5 (**permalink**) 07-13-2003, 05:17 PM

TKO II. Call David Kee. He has a couple in stock.

Aussie Mike · #6 (**permalink**) 07-13-2003, 05:37 PM

Personally I like the T56 and bought one to go in my caar.

The T56 has a standard 26 spline input shaft so it can use the same clutch as the TKO. Yes it is a bit heavier and quite a bit longer at about 850mm including bellhousing. This isn't a problem in an IRS equiped car though and virtually all cobras need a custom driveshaft built anyway. The bellhousing can be a problem if you are trying to mate up to an unusual engine since they have a partially integrated bellhousing. This means that part of the bellhousing is the flange on the front of the box so youcan't just bolt it up like a toploader. This make the casing of the box stronger and the load is spread over more bolts. There are factory belhousings available for quite a few motors, small block for included.

I think the mistake most people make with the T56 is the selection of rear end ratio. Yes it has a very tall 6th gear overdrive but it also has a very tall 1st and 2nd gears. 1st at 2.66, 2nd at 1.78 and 3rd at 1.3 are all taller than the TKO and much more closely spaced. The TKOII has 1st at 3.27, 2nd at 1.98 and 3rd at 1.34. The spread between 1st and 5th in a T56 is closer than 1st to 4th in a TKO. If you equip your car with a 3.9 or 4.1 rear end you will have a close ratio 5 speed with an effective 6th gear overdrive for cruising.

If you are really concerned about the torque handling capacity of the box there is a heavy duty version of the T65 rated at 550lbs-ft PN: TUET1806. Most of the others are rated at 450lbs-ft but from articles I've read there isn't much difference internally. I think it's just different synchro linings.

T56
TKO & TKOII

Cheers

flipper35 · #7 (**permalink**) 07-15-2003, 01:15 PM

Don't know much about the T56, but the TKO II has straighter cut teeth and larger gears than my a833 (Mopar 4 speed). They used the a833 behind some pretty big motors in NHRA drag racing through the 70's.

Gatorac · #8 (**permalink**) 07-15-2003, 04:50 PM

Quote:

The T56 has a standard 26 spline input shaft so it can use the same clutch as the TKO.

The T-56 for Ford has a 10 spline input shaft.

It also has a 2.97 first gear.

A bit different than the T-56 for the bow ties.

Mike Forte may be able to help with a bell housing for your particular application. They come standard with one to fit the 302/351.

The last 3 digits for the Ford aftermarket T-56 is 012. You can see it on the TTC website referenced below.

Aussie Mike · #9 (**permalink**) 07-16-2003, 05:25 AM

If you want a 26 spline input shaft why not use the bow tie T56 with a ford belhousing? The bolt pattern between the box and the bellhousing is the same.

Cheers

Mike

coyled · #10 (**permalink**) 07-16-2003, 07:02 AM

I think both the tko and t56 are strong tranny's and will handle the upshifts well. I believe the weaknesses in both have to do with down shifting and the load on the tranny while decelerating. I broke a tremec when lifting in third gear, snapped it off. Jim, do you road race the car? Is it those little sheet metal detents(3 per syncro) that broke? they usually go first on both tranny's. Scott

CobraEd · #11 (**permalink**) 07-16-2003, 09:22 AM

"The G-Force T-5 kit will handle roughly 600 hp or 500 ft-lb. or torque in a 3300 lb. vehicle running drag radials at the track with a moderate clutch upgrade."

http://www.g-forcetransmissions.com/tran_gt-5.asp

trularin · #12 (**permalink**) 07-16-2003, 10:45 AM

GO CLASSIC!!! Toploader!!!

Gatorac · #13 (**permalink**) 07-16-2003, 03:03 PM

Quote:

Originally posted by Aussie Mike

If you want a 26 spline input shaft why not use the bow tie T56 with a ford belhousing? The bolt pattern between the box and the bellhousing is the same.

Cheers

Mike

Nope. won't work. Do some searching on the Mustang forums and you will see the differences are more than that. Many a Mustang guy has his dreams of an inexpensive T-56 in his car dashed by the reality.

Quote:

Jim, do you road race the car? Is it those little sheet metal detents(3 per syncro) that broke?

Yup and yup.

I now have all the new parts together. Time to see if I can remeber how it goes back together...

Northwood Cobra · #14 (**permalink**) 08-16-2003, 12:31 PM

I'm new here so please excuse my lack of knowledge on this subject. I've got a 435hp 351w with 3.50 gears. I was stupid and bought a light duty t-5 and am now looking for a new tranny. Whats the difference in the tko and tkoII in street application. What's best and where should I go for the bell housing, clutch and shifter to make it all match?

Thanks

Terry

Rebel1 · #15 (**permalink**) 08-16-2003, 11:28 PM

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I'm new here so please excuse my lack of knowledge on this subject. I've got a 435hp 351w with 3.50 gears. I was stupid and bought a light duty t-5 and am now looking for a new tranny. Whats the difference in the tko and tkoII in street application. What's best and where should I go for the bell housing, clutch and shifter to make it all match?
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Have a look at the site CobraEd listed....send G-Force your T5 and you'll get a good heavy duty box back which will handle what you have and then some..and you wont have to change anything.

Seems the best choice in your case.

BMK · #16 (**permalink**) 08-17-2003, 07:38 AM

Hey,

Do we ever work here in Australia. You two guys really get around the threads.

Aussie Mike and Rebel1

I had a spare hour as I have a new Manager working and he thinks I am working on the computer.

Actually I have spent the last hour working out where and who I can visit when in the USA.

Its great looking up hotels/motels etc. and having a virtual tour.

Perhaps the parlours may put the girls on for us. Just think a virtual tour of the Merlins massage parlour

Think I had better stay on the Aussie forum

Cheers Bernie

Bernie Knight
Mt. Gambier - The Blue Lake City
Australia

Home of "Weekend at Bernies"

Venom S · #17 (**permalink**) 08-17-2003, 09:14 AM

I'm using the TKO II with the .80 fifth gear with my 650 HP/600 pounds of torque 503 BBF. No problems at all

Bill

Northwood Cobra · #18 (**permalink**) 08-17-2003, 08:28 PM

I can get my money back or exchange the trany. The car is not rolling yet so it would be very easy to make a change. It looks like the conversion kit is about a 1000 bucks I've already dropped 700 on the tranny itself without all the extras, in your opinion knowing a little more about what I've got, is that still the best way to go or should I get a new tranny that's stronger?

Thanks

Terry