More regarding a T-10 transmission and overdrive

August 1, 2018 | By Staff


I found your response to Nick Bulzomi’s question regarding his search for an overdrive transmission very informative and I researched the A-833 transmission you recommended. However, I was intrigued by the concluding comment you made, that “There are a number of T-10 versions to choose from.” I am not aware of a T-10 with an overdrive 4th gear, but since that would be a better solution for a C-1 Corvette I would greatly appreciate learning of an overdrive gear set for the T-10.


You are quite correct, John. There is no T-10 offered with an overdrive fourth gear, nor can a T-10 be adapted to have an overdrive gear internally because the fourth gear is part of the output shaft of the transmission. I only mentioned the T-10 as an alternative four-speed transmission because it can be had with a number of different gear ratios—either close-ratio or not—that could be preferable to Nick’s stock transmission.

It is possible to equip a T-10 with overdrive though, if you want to attach a Gear Venders overdrive that will allow you to have a higher ratio in all four gears.

It is not a particularly cheap alternative, but it works well. The Gear Venders overdrive is an adaptation of the British Laycock de Normanville systems that have been in use for many years.

The Gear Vendors overdrive is a two-speed planetary gearbox that bolts to the existing transmission allowing the driver a direct drive or overdrive option in any gear at any time. With manual transmissions such as the T-10, not only does the Gear Vendors add a fifth gear overdrive, but its gear splitting capabilities enables you to make full throttle, clutchless shifts too.

You can reach Gear Vendors at:

Gear Vendors, Inc.

1717 North Magnolia Ave.

El Cajon, CA 92020