Okay, you already have a good-sounding, free-flowing exhaust and a much-better-than-stock, free-breathing induction setup on that six-speed C5. The OEM tires and wheels have been upsized and upgraded to something more performance oriented, something more attuned to a C5's capabilities than a set of run-flats. That Fifth-Gen is becoming a little more yours, less The General's, and slightly more of a ultra-performance sports car rather than a highly competent grand touring car. But there's still the matter of the factory-installed shifter. It's not that the stock shifter is bad-it just isn't as taut, as business like as the rest of the car is becoming. You want to shift rather than vaguely rowing the lever around. There are several aftermarket, short throw shifters available for C5s. To the best of our knowledge, all of them are good quality and all will offer improvements over the factory-installed unit.
One of the oldest, most-revered, and best-known makers of shifters is Hurst. The late George Hurst was engineering and building some of the best shifters in the world way back before many of us were even born. There are still lots of older Corvettes, those with T10s or Muncie four-speeds, that have a flat-sided, chrome shifter handle with "HURST" spelled out on each side and a white knob, with the shift pattern engraving, poking out of the floor. In the '60s and '70s, it seemed as though everyone with a manual gearbox installed a Hurst Competition Plus shifter in their cars.
Corvettes have changed, manual trannies have changed, and Hurst, now a division of Mr. Gasket Co., still makes some kick-ass shifters for Corvettes. For a lot of the 40- and 50-something crowd, a Hurst shifter is still the first choice. And that's the case with one of our local car guy acquaintances, Tony Correia.
Ol' Tony fits right in the middle of the aforementioned age category, his beard has gone gray, as has what hair he still has up top. After a lot of years away from Corvette ownership, he picked up a six-speed '99 convertible last year and almost immediately started making the usual minor changes and upgrades to it. The most recent of those was to buy and install a short throw shifter. He checked out the several different C5 shifters that are on the market and found that most are fairly similar-CNC-machined from billet aluminum, have adjustable stops, and the shift throws are shortened up by around 20 to 25 percent. The prices for the various shifters are close-around $250 on average-and at least a couple or three are available through nearly every Corvette parts outlet that handles C5 parts and accessories. He opted for the Hurst for several reasons-above and beyond sharing similarities with the other aftermarket C5 shifters, it has features like multiple-adjustable bias spring loading for the gate (how much pressure or effort it takes to move side-to-side, like from Second to Third, etc.), and a whopping 35 percent reduction in the shift throw.
Back in the good (?) old days, installing a custom shifter in a Corvette meant jacking it up and resting it on jackstands; undoing the knob and boot from the top side; wriggling underneath to unfasten three (most of the time) rods from the trans case and from the shifter body; then unbolting the shifter itself from the transmission and dropping it out-followed by the same procedure, in reverse, to install a new unit. Swapping shifters on modern gearboxes with internal rail shift controls and the shifter body bolted to the top of the case (or on an extension in C5s, where the gearbox is actually mounted behind the driver and bolted up to the differential housing) is much easier. A shifter change in a C5 does NOT require jacking up the car or crawling beneath it, does NOT require disconnecting then reconnecting-and adjusting-a bunch of linkage rods, and does NOT require a huge array of tools.
So, Tony and I got together one recent Saturday morning and within roughly one hour had, from start to finish, swapped out the OEM shifter for a new Hurst Billet/Plus(tm) Competition Shifter (whew!), PN 391 5085. The needed tools were few; a T15 Torx driver, 10mm wrench, 3/8 and 9/16 inch wrenches, 3/16 and 1/4 inch hex key (Allen) wrenches, a small-to-medium size flat blade screwdriver, a pair of Vise-Grips, and a hammer. Our personal recommendation would be to have the following on hand: a Torx driver, metric and standard sockets, hex key/Allen wrenches in 3/8 inch drive with a 3/8 inch ratchet wrench, a screwdriver-type Torx driver, metric and standard boxed/open end combo wrenches, and a old-fashioned hand-held hex/Allen wrenches. That way you'll cover every possibility.
With the needed tools on hand, the job is a no-brainer (Hey, Tony and I did it and made it seem simple!). Hurst's instructions were clear and straightforward-follow them and it'll be almost impossible to screw up.
The real proof of the worth for a modification is if the consumer is pleased with his purchase. Tony was, and still is. As soon as we'd buttoned things up and he slipped behind the wheel, (in the shop) to test throw a few shifts, he started grinning like a fool, We went for a relatively short test ride that Saturday, and the more he drove, the happier he seemed to be. I took a turn and would have to say that this was the best shifting production C5 I've ever driven. A few weeks later, his comments include, "The Second to Third shifts are positive and effortless, the best I've ever experienced." "The car is a lot more fun to drive. Before, it was fun; now it's a LOT of fun! It's a pleasure to use if you want to play." And, "Why doesn't Chevrolet do this from the factory?"
Depending on how you perceive things, there is a downside (or two) to the short throw shifter-there's a slight increase in noise and the shorty shifter definitely takes a little bit more muscle to operate. And ol' Tony doesn't mind at all.
The TV (throttle valve) boost valve is held in the transmission body with a snap ring. Brady used a .472-inch valve (middle), which helps increase transmission line pressure without creating overly firm shifts.
After grinding a taper onto TransGo's handy roll pin removal tube, the two roll pins that hold the throttle valve assembly in place can be removed and the assembly itself removed.
Moving to the other side of the valvebody, we installed a "special" 3-4 shift valve (right) rather than the one included in the kit. The special valve gives '87 and earlier 700-R4s the later shift to overdrive that their '88 and newer brethren came with. Be sure to check the directions for checkballs locations; with the balls in place (use a dab of petroleum jelly to secure them), we're done modifying the valvebody.
After making sure that the TV plunger is the correct one (it should have a "94" or no number stamped in the end), the new valve assembly can be assembled (note the small shim, the flat silver spacer, the red spring, and the new valve with its tapered spring, looking right to left). With the TV bushing (it should have stayed in the valvebody) and plunger bushing properly aligned, the roll pins are replaced.
On the right side of our valvebody (as shown in the instructions), we'll make three modifications. After removing the large roll pin and end cap, the line bias valve gets a new, blue spring (right). The old 3-2 control valve and spring (middle) is removed and discarded. The smaller of the two replacement valves, with its yellow spring, was the right fit for this valvebody (left). After drilling two .110-inch holes in this passage, the new valve is held in with a plug and roll pin.
Carefully following the directions, we labeled each hole in the separator plate with the appropriate letter. Depending on whether you have first- or second-style valvebody, holes will be either enlarged or plugged. For the plugs, insert the proper sized piece, lay the plate on a concrete floor, and smack the plug with a hammer. The edges can then be smoothed with a file. When it comes to drilling, make sure you use the right size bit in the right place. Finally, make sure the proper checkballs are also in place.
We're in the home stretch, but we've got a couple more tasks under the car before we're ready for reassembly. First of all, there's a hole to be plugged (arrow) before re-installing the 4th accumulator piston and spring into its housing as well as these two holes in the transmission casing (arrow).
The 2nd-4th gear servo is on the passenger side of the transmission, and is a bit hard to get at. Once removed, this unit has been overhauled with the parts from the TransGo kit, and is ready to go back into the transmission. We'll end up with firmer shifts; the degree of firmness can be adjusted be altering the washer stack contained within the servo.
After properly positioning the separator plate gaskets and holding them in place with petroleum jelly (don't forget the checkballs!) the transmission can be reassembled. Once the trans is refilled with fluid, a test drive is definitely in order. This trans has been reborn with a whole new attitude, and the improvement in shift quality is marked.
The 2nd accumulator assembly is reassembled with these thick washers and new springs before being reinstalled into the transmission. Depending on the number of washers used, 1st-2nd shift firmness can be adjusted.
We finished up by installing this super-sano billet trans pan from PML. In addition to the cooling fins, this piece has both a drain plug and a temp gauge fitting. Due to the pan's thickness, the stock shift cable bracket needs to be modified. Tune in next month, and we'll show you how it's done.