By the early 1980s, Chevrolet knew of the mandates on the horizon that would require more from the vehicles it turned out each year. Fuel-mileage regulations were a concern along with the fact that America was not willing to let the Corvette’s performance slide down the tubes simply to please the emissions bean-counters. Corvette enthusiasts needed a reason to buy a Corvette rather than an econobox (which would cost much less). Chevrolet had to pull a new ace from the hole that would please both sides and continue the heritage that Corvette owners have come to hold so dear. The 700-R4 transmission was part of the overall plan.

From a performance standpoint, the 700-R4 had a lower First gear than a typical TH-350 or 400, which helped Corvette acceleration "get up to speed" with the driver's expectations, and the Overdrive in Fourth gear pleased those who had miles-per-gallon signs in their eyes. The 700-R4 proved equally pleasing to both sides, and horsepower was steadily increased each year after 1982, when the first 700-R4 was introduced. But transferring that added horsepower to the rear wheels was not without a price. Pump failures, leaking seals, and loose bushings were some of the dependability problems that were straining the relationships between these transmissions and their owners. GM designers wouldn't sleep well at night until this transmission became as good as it was intended to be.

Over the years, several upgrades were made to the transmission housing, pump, and internals, which have made the 700-R4 a perfect choice for a long-lived relationship. Corvette Fever asked Don Marcone of Fourth Gear Inc. in Apopka, Florida, what it takes to make the 700-R4 transmission dependable for everyday service.

The Corvette line has always received the best there was to offer, so the first choice for a rebuild-quality transmission is probably already in your Corvette, if it was built in or after 1987. By then the problems that dogged the 700-R4 had been addressed. If your Corvette is earlier than 1987, you can look at the build date stamped on a flat spot at the mating surface of the transmission housing and the pan to see whether your transmission has been replaced with a newer unit. If you find you still have the older transmission, you can use some of the upgrades and benefit from GM's experience, but they will be found in a newer housing that you will have to locate anyway. Items like the improved governor assembly and valve body, along with higher spring pressures, are all benefits of finding (or using) your original Corvette transmission.

Don sells transmissions on an outright basis and can design a 700-R4 transmission to suit your particular needs. The customer receives a new TV cable, fluid tube, and dipstick with every transmission.

SOURCE
Fourth Gear Inc.
Apopka
FL