How To: Shift to protect your drivetrain

Updated Nov 5, 2009

You can minimize clutch and drivetrain repairs by shifting properly, especially in certain conditions.

A gentle start on a soft surface can cause the clutch to overheat when it doesn't fully engage.A gentle start on a soft surface can cause the clutch to overheat when it doesn't fully engage.

START IN THE RIGHT GEAR. This will minimize clutch slippage. When loaded on level terrain, this means 1st (not Low) gear in a 13- or 18-speed, and 2nd in a 10-speed. Going up a gear or two on a downgrade or when unloaded is okay if clutch slip time is still less than 2 seconds. But doing things like starting in 3rd with a 13/18-speed (or 4th with a 10-speed) loaded and on an upgrade stresses the entire drivetrain. Part of the problem is you will need to use the throttle to increase engine rpm, which increases engine torque output to a level far above what it is at clutch engagement rpm.

BE CAUTIOUS WITH SOFT TRACTION. Two-pedal automatics are designed for hard pavement only. The transmission and clutch can get into trouble when you’re stuck. When trying to gently start in mud or snow, the wheels often turn so slowly the clutch won’t fully engage, and this will cause it to overheat. If you get stuck, make sure you use enough throttle to quickly get the rpm up to where the clutch will engage fully, significantly above idle. If this causes you to just spin the wheels, get a tow.

FLOAT-SHIFT SPARINGLY. Experts admit constant-mesh gearboxes are designed for this, but they recommend caution. Consider the size and weight of the components involved. If you use the clutch, only a few transmission parts and the clutch disc need to be synchronized with the driveline by the shift collars. But when your left foot’s on the floor, all rotating engine parts are involved, including the flywheel. Unless you synchronize rpm perfectly, the result will be a harsh shift, which can easily damage shift collar teeth. So when climbing a steep grade, or when you’re fatigued or distracted, use the clutch. n