5 speed trans options

[Greg]

Hello, My Shelby is a nice driver (or was as I have pulled the engine out to go through it  .  It will be a few years before I tear the car down completely but I want it to be interstate friendly now.  I have the T10M aluminum trans (which I am obviously keeping) but I am thinking about putting a 5 speed in it for now just to drop the RPMS on the highway.  This would allow me to drive it for 3-4 hours away to car shows and not run 3,000 rpms at 75MPH.  I'm not cutting any holes as the old girl has lasted this long without molestation and I'm not going to be the first.  I just want a simple trans change without structural changes so the engine isn't screaming for an extended period.

Any advice?

thanks, Greg

[Jim Herrud]

Hi Greg,
Modern Driveline is a well know supplier of T5 upgrades for vintage Mustangs. Several of the Mustang magazines have articles on this very popular swap. Since MD is located close to where I live, the choice was easy for me. My '65 Fastback had 2.78 gears in the back with a T10 as well.  Originally running 215/60R14 tires, I was right at 3000 RPM at 75MPH. I have changed to 3.89 gears and the Ford Motorsport T-5z with a 0.63 overdrive. I will run 17" wheels and expect to be at 2500 RPM at 75 MPH in fifth gear.

The owner at MD, Bruce Couture, is a real stand-up guy. I met him through our local Mustang Club. He and his crew have patiently answered my questions and gave me a great tour of his shop outside of Caldwell ID. The website has a lot of info, so even if you select another vendor, there is a lot to learn here. My car is not yet running, but several club members have done this swap using Bruce's services and have nothing but good things to say about it. (And no, I'm not sponsored - though I drive like I am;)

Jim

[jamesfee]

Greg,
+1 - Bruce at Modern Driveline; I got a tremendous amount of help from him when I put a T-5Z in 1801. It was singularly the best upgrade I have done to the car. Bruce worked through getting me connected to my 5 bolt COBRA bellhousing, which needed an adapter plate. I'm on the East Coast so all of this was done via pictures in email and phone calls.

The only "major" change to my car was that my specific installation ended up needing a shorter driveshaft - and I simply had a local shop fabricate one so my original is untouched. I stayed with stock clutch linkage and no modification was necessary to the tunnel. The T-5 has a shifter that even looks like the stock Ford unit.

I am running a 347 stroker with Webers so it handles the power/torque well. I have been running this setup since 2006.

jim

[2112]

What is the upper end capabilities of the T5?

I am sure most of us here would not be in that HP/Torque arena, but I thought guys were grenading their T5s? Maybe that was with modern, blown modular engines?

[Greg]

What is the upper end capabilities of the T5?

I am sure most of us here would not be in that HP/Torque arena, but I thought guys were grenading their T5s? Maybe that was with modern, blown modular engines?

That was my impression as well but it must be adequate up to 400HP

[jamesfee]

It depends on which T-5 you get. There are 3 primary variants, W/C NWC and the Z spec. I'm running the Z spec which was used behind the '93 Cobra Mustang and is rated at 330 lb-ft. Given that I wanted a spirited  driver and not a frequent drag racer I have no issues with it. Some of the earlier models were not as robust.

jim

[Jim Herrud]

+1: Jim's reply. I discussed the T-5 variants with MD and they assured me theirs is of the preferred, robust design. (Then again, what would you expect them to say;)  MD offers a Tremec T-56 6-speed with a higher design torque limit. I looked at this unit, but it requires some clearance modification in the '65-66 tunnel area - something i didn't want to do. My 289 dyno'ed at 340 torque and I plan to use it for autocross. MD felt that the T-5z would work fine in this application. Besides, it fits without mods and is lighter to boot.

Jim

[427heaven]

I have used a t5 in my coupe t/a race car for some time with no issues,as stated before there is no magic number when it will let go or give problems. There are a lot of variables such as shock load, how old and worn out it is, usage,type of lubricant,heat etc. 350-400 hp seems to be its range with no problems for typical performance use. Make sure you get the v8 version they also backed up 4 and 6 bangers DONT USE THOSE! Modern drive line guys are great ,I run one of there cable shifters not wanting to run a hydraulic clutch. This covers MOST of the cars wanting the upgraded 5 speed, if you really got a lot of beans under the hood consider the t56 you wont regret it!

[2112]

If you have a '67-'70, does the Tremec T-56 fit without mods?

[KR Convertible]

I doubt it.  T56 is huge.  You might get away with a TKO if you need something to handle more torque.