Using factory parts to upgrade my Chevrolet Corvair’s shifter
My 1965 Chevrolet Corvair is not stock, but it is not a hot rod either. I have spent time carefully curating tasteful upgrades that don’t detract from the overall aesthetic of car. Most of the time that involves modifying parts or ordering aftermarket bits, but occasionally my thrifty side comes out and I raid the parts bin rather than the order catalog in my pursuit of performance.
The Corvair’s is a prime example. With its rear-engine layout, the car requires a six-foot tube to connect the gear shift between the bucket seats and the selector shaft on the transmission. That tube required rebuilding on my car, like most half century old cars, but even with no play in the mechanism the shift throws were not what I desired. Short throw shifters feel racy and I always thought the Corvair’s throw was a little too long for the sports car I wanted it to be.
There is a short-shift kit available from Clarks Corvair, one of the largest Corvair parts suppliers, that adds two pieces to the shifter, effectively reducing the travel of the gear lever between gears by extending the lever’s reach from the pivot point in the shift tower. I installed that kit, which consists of an extension for the gear lever and a riser for the base plate, on the 1964 Corvair I drove through my senior year of high school. It works, but I regularly had to adjust it (and finding reverse was a real bear). Tired of dealing with the aftermarket solution, I did some research and found a factory-made alternative.
Corvairs were available with three transmission options: a two-speed Powerglide automatic, a three-speed manual, and a four-speed manual. In 1965, the three-speed transmission required greater selector shaft movement than the four-speed to engage the proper clusters in the transmission. Rather than use the same shifter for both transmissions, which would have likely resulted in the three-speed suffering from very long shifter movements between gears, each transmission received a unique shifter. The transmissions were changed slightly in 1966, allowing the use of the same shifter for both three- and four-speeds. This leaves a one-year-only part that has greater leverage over the shift mechanism, and when paired with the four-speed trans, will deliver shorter throws.
The science behind short-shift mechanisms is pretty simple. It’s all about leverage, and the location of the pivot on the shift lever itself determines the amount the lower portion will travel relative to the upper portion. Looking at the two shifters side by side, you can see the three-speed shifter has a higher pivot point, giving it a higher ratio between the movement at the shift ball and the movement transmitted to the shift linkage. Higher ration equals shorter shifts.
There is a drawback, though—increased effort. With that higher leverage comes the need for more muscle to move the shifter through its movement. The quick shift kit I utilized in the past required higher effort than I liked, and I sometimes had to jerk the shifter around to get into gear. This three-speed needs more effort than the stock four-speed unit, but not dramatically so. It just feels noticeably stiffer than factory, which is perfect. Other than the pivot height, the 1965 three-speed shifter can be identified by its black lever, rather than chrome or polished.
It actually took me two years to locate a usable 1965 three-speed shifter, and the one I found is missing a fair amount of aluminum due to corrosion. It is serviceable, but I am always on the lookout for a better-condition base. For now though, the shifting system is sorted and working great. If I could get the rest of the car on the same program, I’d be in prime shape for spring cruising.
If you need me, I’ll be wrenching in the garage.