Shifter Linkage Adjustment for 1997-2019 Corvette (C5, C6, C7)
Background: If you are having problems with gear engagement, or have removed or loosened any of the lower shifter parts, follow this procedure to realign the box and rail to the shift shaft rod coming from the transmission. In doing so, the shifter will be aligned to be orthogonal and centered in neutral, to allow for proper range of motion to reach all gears without blockage.
WORK SAFELY! Park vehicle on a clean level surface and perform this work with engine turned "off". Place wheel chocks in front and behind both rear wheels to prevent movement in either direction as parking brake may be released during process. Do not attempt procedure until you are confident vehicle is secured and will not move.
- Apply parking brake.
- Remove console trim and/or instrument panel trim as applicable (varies by model); refer to shifter installation instructions or GM service manual.
- Remove shifter closeout boot (attached to floor pan).
- Study area below shifter base. Note shifter base is mounted onto an aluminum housing or box, and this box is attached to the torque tube via two large T40 Torx bolts on right side, at front and rear. At the rear of the box is a protruding shaft that attaches to a clamp which also has a large T40 Torx bolt. At the front of the box is black plastic extension with a small hole on top; this extension is attached to the front of the box by a phillips-head screw on each side. Sometimes these screws loosen so it is important to make sure this extension is tight; if not, you may need to remove the box in order to tighten these screws. If the extension has been loose for some time, the bushings at front and rear that support the inner rail may be damaged and the entire box may need to be replaced.
- Identify or obtain neutral lock pin. If stock shifter is present, look for the bent steel pin immediately in front of baseplate, partially inserted downward into the black plastic extension attached to front of base box. If an aftermarket shifter is installed, you will need to find this pin (perhaps with the old stock shifter) or something like it - a 4mm / 5/32" straight punch or drill bit - or worst case get a M4 screw at least 25mm in length. Get a Sharpie marker and make a mark ~20mm from bottom of pin for depth reference.
- Confirm parking brake is still engaged. Place shifter in neutral.
- Loosen the T40 clamp bolt and the T40 box bolts all by a few turns to make sure the connections are free to move. Note bottom of shifter box has a tongue that hooks into a pocket on the torque tube; make sure these features are overlapping and engaged.
- Engage neutral lock pin. This step is to align the inner shift rail shaft to the plastic extension, which centers and aligns the inner rail relative to the box. On stock shifter, simply press down on pin until top bottoms out on baseplate (~14mm downward). For aftermarket shifter, insert pin until it is fully engaged (~20mm deep). Do not force pin; it should all but fall in place if everything is aligned. If not, wiggle shifter at top slightly side-to-side and front-to-back to help align the parts.
- Tighten the two T40 box bolts to 30 Nm (22 ft-lb). After box bolts are tight, tighten the T40 clamp bolt to 30 Nm (22 ft-lb). Then, confirm shifter base bolts are tightened to 12 Nm (106 in-lb).
- Lift / remove neutral lock pin, test shifter operation, replace closeout boot, and replace trim.
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