daves garage

One Hand on the Lever

Shift Fork

This month’s question comes from Wendell Noble. Anyone who knows Wendell and Mary know they have a preference for manual transmissions. Wendell asked me if I knew why his owner’s manual advises not to keep a hand on the gear shift lever while driving. 

The answer is, yes, I know. The gear shift lever is connected to the shifting forks inside the transmission via a mechanical linkage. The shifting fork slides an engage-ment dog to lock the gears together when you shift. The en-gagement dog spins with the gears, the shifting fork remains stationary. When the operator rests his hand on the gear shift lever, some force is transmitted through the linkage to the shifting fork. This force creates friction between the shift fork and the engagement dog, causing wear. 

Often, when a vehicle gets some age and use, the transmission linkage can develop a rattle. This can sometimes be silenced by holding the gearshift. This often is the genesis of a long lasting bad habit of resting a hand on the gearshift lever. To fix a rattle, the linkage can usually be repaired, either by tightening loose hardware, or replacing worn bushings. 


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