TEXAS DRIVETRAIN
PERFORMANCE
TEXAS DRIVETRAIN
PERFORMANCE

Tremec T56 Transmission Rebuild: Common Questions and Issues

Arguably one of the most versatile and performance-minded beasts on the market, the Tremec T56 transmission sets the standard high. This premier manual transmission offers an incredible amount of power, impressive gearing, great torque capacity, and reasonable gas mileage.

Boasting 6-speeds of engineering marvel, the T56 transmission was built and designed by none other than Borg-Warner. Borg-Warner later transitioned over to Tremec in 1998.

In its later years, we have seen the T56 rise to fame for its use in the popular LS-powered Pro Touring builds. That said, the T56 transmission has a storied past riddled with performance highlights. The debuting of this magnificent 6-speed manual transmission was in the 1992 Dodge Viper. Then in 1993, the T56 appeared in the Camaro Z/28. Fast-forward a bit and the T56 made big splashes when it replaced the ZF six-speed transmission in the Corvette. 

Since that time, the Tremec T56 has evolved its platform to take on several roles and iterations among GMs makes and models. Each new transmission containing its own unique performance specs and nuances.

Tremec Transmission FAQs: T56 Rebuild

A: Only consider a T56 rebuild if it is an incredible price. Unfortunately, lack of knowledge has driven the market price way up. The fact that a given T56 will shift through all the gears doesn’t guarantee that it’s a good transmission. The T56 is getting to be an older transmission and no one drives them nice and easy. Not to mention, they are forgiving units which means that it can be in bad condition and still shift though the gears. We’ve seen many T56 units that require an expensive rebuild shortly after purchase, exceeding the cost of a new Tremec Magnum.

We recommend disassembling the car’s transmission before ordering any parts or kits. You will likely need more than the kit alone. It is best to check everything out and then order the parts.

Add the cost of the rebuild kit plus hard parts. The hard parts are the gears, synchronizer assemblies and shafts. The condition of these parts are unknown until the transmission is disassembled and inspected.

Case scenarios listed below:

  • Best – low $1000 range
  • Worst – $3000 range
  • Average – $2000 range

This is to build the transmission correctly, making it better than new.

Warranties are posted on the warranty information page.

It is highly unlikely that it’s a simple fix. The T56 transmission is very forgiving, and can be in bad shape and work in most of the gears.

Yes, we can service and fix a minimal amount of T56 items. This would be just enough to get it working (patch up), but this is not the correct way to do the job. If there is an issue in one gear, it is likely that there are other issues progressing in the clutch as well. The problem has to get really bad before it shows any symptoms, so it is common to have hidden issues. Discovering these issues happens when the transmission is disassembled and inspected. If a shop does offer a patch up, it is a matter of time before other issues begin surfacing. This means it will have to be pulled and fixed again.

It may be worn engagement points on gears and sleeves.

Each T56 gear has a row of engagement teeth around the perimeter. There are tiny sharp teeth that mesh with the corresponding synchronizer sleeve engagement points. These points tend to get rounded off and dull over time. Theoretically, these are not wear items and shouldn’t have to be replaced. They really don’t wear out, rather they receive damage from the synchro ring friction material getting low. This introduces more play and the synchro ring isn’t able to do its job efficiently which causes these engagement points to grind. It’s inaudible at first, but eventually they get worn down to the point where the grind is audible. This is a long process that takes years before there is an obvious problem. We wouldn’t want to leave half-worn components inside the transmission during a rebuild. This would cause issues later on. The only way to do the job right is to replace these worn parts with new high quality products.

Another possibility is worn 5-6 cluster gear splines and corresponding mainshaft journals.

This is the infamous issue with the T56 transmission in almost all applications. The 5-6 driven gear is pressed onto the mainshaft, but is only splined about 20% of the total length. This is a major design flaw that didn’t stand the test of time.

The gear gets loose and starts to rock. Once this begins, it gets progressively worse until it eventually wears completely through the splines. Once that happens, the transmission loses the use of 5th and 6th gear. This can cause a high-speed vibration and excessive road noise. Or, in some cases it’s not obvious until someone inspects the disassembled transmission. The repair for this would be to replace the stock mainshaft and 5-6 driven gear.

This means the transmission overheated, which is usually due to lack of fluid. Overpowering the unit can also be the cause. The repair would include replacing the input shaft and the countershaft. All of the power of the vehicle is channeled though the input shaft, which serves as the main drive gear. It’s directly meshed with the countershaft teeth, so this is the area that gets burnt up first.

Looking to upgrade your T56 or TR6060?

The Most Versatile Performance Transmission

Arguably one of the most versatile and performance-minded beasts on the market, the Tremec T56 transmission sets the standard high. This premier manual transmission offers an incredible amount of power, impressive gearing, great torque capacity, and reasonable gas mileage.

Boasting 6-speeds of engineering marvel, the T56 transmission was built and designed by none other than Borg-Warner. Borg-Warner later transitioned over to Tremec in 1998.

Tremec T56 Transmission Rebuild: Common Questions and Issues - Texas Drivetrain Performance

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