[Web Creator] [LMSOFT]
VT Commodore Gearbox Issues
Phoenix Mechanical

T-Bar shifters - Some VT's have a rattle from the T/bar shifter. This may be cause by the pin that joins the t/bar lever to the transmission selector linkage. Revised linkages were introduced mid 1998.

V6 Selector Linkage - Part number 92048113

V8 Selector Linkage - Part number 92048112

In some VT's, a clunk may be heard from the shifter when moved into the park position. A transmission slider guide was introduced mid 1999.

Transmission Slider Guide Clip - Part number 92059509

Clutch Fluid Reservoir Cap - Some clutch master cylinder caps failing by cracking (with the top of the cap cracking where it attaches to the threaded section of the cap). A revised cap was introduced mid 2000.

Clutch Master Cylinder Cap and Seal – Part number 92144027

Gearshift Knob Rattles Gen III Manual - The gearshift knob may vibrate to the point where it can generally be heard in 3rd or 4th gear at wide open throttle between 2500 to 4000 rpm. This condition is a result of excessive clearance between the shifter knob and the shifter lever. From March of 2002, gearshift knobs were glued on.

Gearshift Rattles Gen III Manual - Under certain driving conditions some VT's may develop a rattling gear shift lever. This condition is different to gear knob rattle. The cause of the rattle may be due to excessive clearances in the remote shifter linkages. A revised remote shifter was introduced late 2003 to eliminate rattles.

Shifter Upgrade Kit VT/VX type - Part number 92147248

Soft or Low Clutch Pedal (Gen III) - In some VY's, the clutch pedal may feel soft and/or has a low disengagement point, along with some difficulty selecting gears. A cause of this can be the clutch slave cylinder. In certain situations, a corrosive chemical reaction can occur between the clutch fluid and the clutch slave cylinder housing. This chemical reaction can produce a gas in the hydraulic system that can give a soft or spongy feel to the clutch pedal. A revised clutch slave cylinder was released late 2003. The new cylinder was made of a different alloy, and was more resistant to chemical reactions.

Clutch Slave cylinder assembly (revised alloy) – Part number 92067460

Excessive Gear or Road Noise from Shifter Area (6 speed Manual) - Some VT's may have excessive road or gear noise coming from the transmission shifter area. This can be caused by a split inner boot, or a loose retainer plate. A revised gearshift boot and retainer plate was introduced early in 2002, which is of a more durable material (white in colour), and the retainer plate has 4 studs and nuts (instead of 4 holes and nutserts in the sheet metal).

Gearshift Boot Assembly (4 holes in retainer plate – no studs) up to vin # L832048 - Part number 92145520

Gearshift Boot Assembly (4 studs in retainer plate) From vin # L832048- Part number 92065868

V8 Manual Oil leaks - The tail shaft yoke that enters into the rear of the gearbox can be responsible for oil leaks from the rear of the gearbox (usually blamed on the rear gearbox seal). A revised yoke was introduced late 1998 with improved sealing abilities.

Clutch Growl (5.0ltr V8) - A growl like noise (from the pedal area) may be heard when the clutch pedal is released at mid to high revs. Apparently this is caused by the clutch pressure plate, and the noise is transferred to the hydraulic clutch system. A hydraulic damper was released to help reduce this noise.

Damper and pipe assembly - Part number 92082692

Clutch pedal Squeak - The clutch pedal to clutch master cylinder pushrod pivot pin and bush may become dry and squeak. Applying Molybond GA10 Grease to the pin and bush will help reduce squeaks.

Spigot Bearing Noise - A squeal may be heard from the spigot bearing, at the first use of the clutch pedal after a cold start. The noise may repeat several times when the clutch is disengaged, during engine warm- up. Possible causes can be the incorrect fitment or damage to the spigot bush, or the lubricant used on the spigot bush dries out. Revised tooling was introduced to minimize possible damage, and the spigot bushes are now impregnated with synthetic oil (10% molybdenum disulphide).

Spigot Bush - Part number 92116034

Gear Engagement (Gen III Manual) - Some VT's may have trouble selecting reverse gear, or the selector does not go into reverse completely. When the clutch is released, grinding of the gears may be heard if reverse isn't fully engaged. The gear selector may also need to be physically held in reverse to use the gear. A possible cause can be a circlip missing from the forward pivot of the shifter rail. A missing circlip can allow the gearshift pivot pin to partially disengage and become loose, making gear selection difficult.

If excessive effort is used for gear changes, the Remote Shifter Mechanism front pivot ball may dislodge from the nylon retainer. If the pivot ball dislodges, no gear selection would be possible. A metal reinforcing plate was introduced to prevent the ball from dislodging.

Gen III Vibration - Some VT's may suffer from an excessive vibration, which is felt within the vehicle. Vibrations may be felt when A. The vehicle is stationary with the engine idling in gear and the A/C is on , B. When the idle speed drops during automatic gear selection and/or a steering load is applied, or C. During slow acceleration or low speed driving in a low gear, with engine speed between 650 and 1000 rpm. Several areas may cause these issues. One area is the PCM calibration, which was later revised with improved idle speed control. Another area may be a stressed exhaust system. A Bent catalytic converter bracket is an indication that exhaust stress is evident (this should be straight). Spacers can be added to keep this bracket straight when bolted in place.

Catalytic Converter bracket bolt - Part number 90495649
Flat washer (spacer) - Part number 120394

Along with a sequence of loosening and retightening exhaust and mount bolts, extra bolts were added to the rear gearbox mount.

Gearbox mount bolt - Part number 92138301

Gearbox mount nut - Part number 11086962 (torque to 45-55 Nm)