T56 Synchronizer Ring for 5th and Reverse Gears

This is the synchronizer ring that lives on the 5th and reverse side of the Tremec T56 six-speed. It is Motive Gear part number 1386591005, sold as one ring. On a T56 the 5-R synchro takes the most abuse of any position in the box: reverse has no synchronizer of its own on most builds, and 5th gets slammed at highway speed on a hot gearbox. When the cone coating wears off, the ring stops matching shaft speed and you get the classic T56 complaint - 5th grinds going in, or reverse balks and clunks unless you clutch twice.

The T56 was used behind the LT1 and LS1 in 1993-2002 Camaro and Firebird, the C5 Corvette, 1994-2004 Dodge Viper, 2003-2004 Mustang Cobra, 2004-2006 GTO, and the Ram SRT-10. Any of those cars with over a hundred thousand miles is a candidate for this ring, and it is worth checking the 5-R ring any time the case is split for a bearing or fork job.

Installation is inside the transmission, so the box has to come out and be opened. Pull the tail housing and the shift forks, slide the 5-R hub and slider off the mainshaft, and lift the old ring off the gear cone. Before the new one goes on, set the ring square on its clean, dry gear cone and measure the gap between ring face and gear teeth with a feeler gauge - if a fresh ring closes up tight against the gear, the cone itself is worn and the gear needs replacing too, not just the ring. Coat the ring in the same fluid you are refilling with, seat it, and reassemble in order so the slider teeth line up with the ring dogs.

Motive Gear covers this ring for one year or 50,000 miles. It is machined to OE dimensions and drops into a stock T56 with no modification.