While the transmission in...
While the transmission in our '96 coupe performed flawlessly at wide-open throttle, it was prone to the occasional slip or indecisive shift in everyday driving. Factor in a copious ATF leak, and it was clear that restorative measures were in order. (Photo by Kevin DiOssi)
Working on an older Corvette is a bit like playing a game of mechanical Whack-a-Mole: knock out one problem, and another one immediately pops up. In the case of our '96 Polo Green coupe, we've recently spent the bulk of our time concussing critters in the differential, the better to prep the car for a planned raft of power upgrades. The solution ultimately came in the form of a heavy-duty Dana 36 diff from Zip Products, which went in with a minimum of fuss and has thus far performed beyond even our admittedly high expectations.
To minimize the car's downtime...
To minimize the car's downtime during the rebuild, we obtained a used trans to serve as the foundation for the job. West Coast Vette specialists J&D Corvette sent us this low-mileage unit, which came out of a wrecked '94 model. Along with a vast inventory of new and used parts, J&D offers everything from light paint- and bodywork to complete Corvette restorations.
With the diff squared away, it was time to focus our sanative attentions on the car's rebuilt 4L60E transmission. While the factory-issue trans was still cracking off rifle-shot upshifts under wide-open throttle, it had developed a barely perceptible slip when engaging Fourth gear in everyday driving. Around the same time, it sprang a festive fluid leak that left decorative Rorschach patterns on the garage floor. While neither of these issues demanded immediate attention on its own, together they constituted a clear indication that the 80,000-mile gearbox was nearing the end of its useful service life.
All of TCI's Pro Super rebuild...
All of TCI's Pro Super rebuild kits come with gaskets, seals, a high-volume filter, and everything else you'll need to perform a full, performance-oriented overhaul. Specifying the "Ultimate" version (PN 378955) nets you heavy-duty Alto Red Eagle clutches, power bands, and Kolene-treated steels in place of the standard-issue pieces. Since we'd also be adding a torque converter with a higher-than-stock stall speed, we decided to install one of TCI's Performance Coolers (PN 823500) as part of the job.
Rather than simply overhauling the transmission with new stock components, we decided to load it up with race-spec hardware from drivetrain specialist TCI. The Mississippi-based company provided us with a full complement of severe-duty internals for the trans itself, along with one of its high-stall StreetFighter torque converters to enliven our C4's standing-start acceleration.
To minimize the car's downtime during the rebuild, we also obtained a used stock 4L60E from Vette-parts specialist J&D Corvette in Bellflower, California. J&D shipped us an almost-new unit from a wrecked '94 model, which we turned over to local tuner AntiVenom for the freshening-up work. Once that was done, the AV crew headed back to Source Interlink's lavishly equipped installation center to perform the swap. Follow along now as we take a closer look at both the parts themselves and the highlights of the job.
The stock 700R4/4L60E sun...
The stock 700R4/4L60E sun shell is famously failure prone. TCI's "Beast" unit (PN 373900) is thicker than the factory piece and uses a revised spline area that's better suited to high-horsepower use.
With the car on a lift, AntiVenom's...
With the car on a lift, AntiVenom's Casey Willard begins the job by removing the exhaust system aft of the catalytic converters.
With a stall speed of around...
With a stall speed of around 2,800 rpm (stock is approximately 1,800), this 10-inch StreetFighter torque converter (PN 243106) should boost the car's off-the-line verve immensely. A full complement of beefed-up internals-including needle bearings, furnace-brazed fins, and a heavy-duty lock-up piston-makes the StreetFighter's roughly $580 price tag a relative bargain.