Critical internal components are shared - both rated @ 700 lb. ft.

 

Mainly just where the shifter is positioned.... I'm pushing over 1200rwhp thru a 100% stock T56 Magnum .... But I don't launch it hard. Radials on sticky tires will break things faster than running a bias ply tire.... also using a twin/triple disc clutch that won't allow slip will break parts quickly when it hooks up if you side step the clutch at launch under boost. A clutch tamer device is a wise investment if you want great 60ft times.

This was the 1st pass testing the 88mm turbo many years ago and was in the 1.6 range for 60ft on a private track rental. We only went to the drag strip a few times. It is mostly a street plus 1/2 mile car and even then doesn't really have the proper safety equipment (4pt roll bar).

 

My friend has an 03 Cobra. It’s pretty much stock, just I/H/E. The issue is that once you get above ~6500, it just doesn’t want to shift 1-2. No grinds, just literally feels like it’s blocked. Another one has a 2020 Mustang GT, exact same issue.

A guy with a C5 said after he destroyed the T56, he put the Magnum in and the RPM related shift issues went away.

Do these transmissions have an issue shifting above 6, 7, 8k?

 

Not just during launch, there's a lot of stored energy that needs to go somewhere almost instantly when changing gears. A proper clutch for the application will help get the most power thru any given transmission.

Grant

 

I had an LS2 powered supercharged 3,800 lb daily driver, ( only making 530 HP at the crankshaft) driven on drag radials, but only on the street. I had a factory T56 and I drove it real hard, ( not a whole lot of burnouts though) and I blew that trans which had 8,000 miles on it. I replaced it with a TR6060 trans and never had a problem again.

 

Is the TR6060 a direct replacement for the T56?

 

Quick overview: T56 was originally in the 1993 Camaro and not much changed when it had a different input shaft and front bearing plate to use in the LS 1998 Camaros both with 27 spline output shafts (weakest link when making big power... so many upgrade to the Viper 30 spline output shaft). The older 2006 T56 transmissions share zero internals with newer T56 Magnum/TR6060 transmissions. A Magnum is basically a universal case with a slip yoke style driveshaft feature and TR6060 internals. The newer style case even weighs 4lbs more. The internals are now made from a better grade steel, wider gears, different synchros (shorter for faster engagement), and a 31 spline output shaft which all add strength. The production version TR6060 normally has a CV style driveshaft and a floating shifter plus non removable bellhousing which is hard to retrofit.... the Magnum has a shifter directly bolted to the tail housing making shifts feel much tighter plus a removable bellhousing. Most TR6060 production units have 3.01 1st gear which is super short and the following gear spread is kind of all over the place. The 2.66 version found in the ZL1/CTSv TR6060 is the same gearing as the T56 Magnum 2.66 gearing... I don't like the 2.97 1st gear offering in the Magnum and try to never recommend/sell it.

My older T56 rebuilt from a 2002 Camaro didn't have issues shifting at around 7000rpm... my newer T56 Magnum F (bolts right up and is dimensionally identical) shifts at 7800rpm no issues (LS turbo) and only change was to a 31 spline yoke. They put these also behind turbo 2JZ cars and shift at 10,000rpm+.

If your Cobra buddy is having shifting issues he probably needs to convert to hydraulic operation or maybe has a clutch that isn't releasing properly... or just should buy a Magnum .

Tremec is also no longer supporting the older T56s with replacement parts and completely stopped making the TKO 5speed (which shifted like garbage compared to the newer TKX).

If you need a T56 Magnum reach out.