T56 Transmission Swap

[DeepList]

I'm considering a swap to the T56 transmission in my 99 cobra, that is if I come across somebody that has one and doesn't want an arm and a leg.

Aside from the driveshaft length, what else would be different? What other pieces would I need. Different cross-member? Any custom fab to make it work?
I've done a complete engine swap before in my 99 sixer, so I'm not a complete noob, but this would be a bit outside of my normal realm.

With the 4:10 gears, what would be the overall advantages vs disadvantages be to doing this if I decide to go through with it?

 

[Javi]

Pinion flange, driveshaft, crossmember and u-joints.. but the u-joints might come with the driveshaft

 

[castine917]

Choice on way of engaging reverse.

 

[DeepList]

Choice on way of engaging reverse.

What do you mean?

 

[greenscobie86]

He means that you'll have to wire up an custom electric lockout for the reverse gear. But if you got to svtp there are write-ups on this topic and some gentleman even made custom splice in speed sensor that will emulate a reverse lockout function on swapped cars.

 

[BigBore96]

Can I ask you why you are going to a t56?


Here are some con's (assuming its a standard Termi t56)

1. Robs more power than what you have now.
2. Heavier.
3. It's still basically a 5 speed tranny. The sixth gear is basically our 5th gear. And the t56 5th gear is basically a gear between our 4/5 gear in our 5 speeds.
THIS DOES NOT APPLY TO AFTERMARKET BUILT T56's


Just a few things off the top of my head.

 

[DeepList]

BigBore96, thanks for that info.

It's just an idea that I was throwing around, so I was searching for input from people who may have a little more knowledge on it than I do. For the most part, I am searching for opinions on whether it would provide any benefit at all, and if so, whether those benefits would outweigh the disadvantages.

 

[LilRoush]

I love my T56. I have run autos, five speeds, built five speeds and now a stock (Terminator spec) T56. It is my favorite of any trans I've ever run in a Mustang. Keeps me in the power band much better with the gearing compared to the 5 speed cars.

 

[white95]

That "extra gear" between 4th and 5th will keep the RPMs up and allow for better accelerating (really only prevalent in a top speed trial here) before going into overdrive.

 

[DeepList]

I already shift extremely fast because of the 4.10 gears. During normal driving, I seldom ever use 1st gear because it's a waste of time. If I do, I'm already shifting to 2nd before I've entered the intersection. If the T56's 6th gear is essentially the same as our 5th gear, I see no benefit... Unless the 6th gear on the T56 is a more suitable ratio for highway driving, keeping the 4:10s in mind.

 

[white95]

Let's compare:


2003 Cobra T56


1st - 2.66
2nd - 1.78
3rd - 1.30
4th - 1.00
5th - 0.79
6th - 0.63


1999 Cobra T45


1st - 3.37
2nd - 1.99
3rd - 1.33
4th - 1.00
5th - 0.67

The higher 1st gear would give your blower something to pull against.

 

[DeepList]

Interesting stuff. So from a professional standpoint: would the T56 swap be worth the time, money and hassle... or just a waste?

 

[white95]

Worth it...

On one hand, when/if you ever step the power level up, you'll already have a stronger transmission in place. On the other hand, you'll have a more useable 1st-2nd exchange and that means quicker ET's/passing/whatever you do.

 

[DeepList]

Cool. It's not really something I plan to jump all over, but I'll keep my eyes peeled locally for a T56. If I can find one for a good price, this may be something I'll tackle. Thanks for the input.

 

[white95]

Sure man, anytime.

 

[castine917]

Other reverse options include lots of muscle, lighter spring, no spring(could miss 5th and go into reverse).


If you find one with a .50 overdrive your highway rpm would come down more than the 2003 cobra ratio. Those ones usually have a different 1st ratio though and may not be what you desire. The t56 i went with has the following. Haven't driven it yet to tell how different it feels.

Gear Ratio
1st 2.97
2nd 2.07
3rd 1.43
4th 1.00
5th .80
6th .62

 

[DeepList]

Interesting. I would assume if I got a T56 from a different car, like a Camaro, vette or viper, I'd have to change out some stuff like the input shaft and bell housing.

At that point, rather than running the risk of ****ing something up, it may be easier to just get something like this:
http://www.ddperformance.com/shop/product_info.php?products_id=186cPath=107_124

Thoughts?

 

[castine917]

That is just the trans and doesn't include any of the parts javi listed. Should be stronger than the one I have and those gears may match what you desire. You won't shift out of first as fast and will lower rpm on highway.

What tooth count is your clutch?

 

[chuddleston2003]

Yeah Deeplist that is the tranny I am going to be putting in when I build my motor up and put the supercharger on it. Expensive little booger isn't it.

 

[MustangChris]

if you do it, please do a detailed write up. I plan on doing it when I pull my engine again.