The short, square or slightly undercut teeth on the face of a gear and on a sliding collar or clutch ring that lock the two together, so a freewheeling gear on a mainshaft becomes the one carrying torque. In a crash box and in most race and motorcycle gearboxes, the dogs engage directly; in synchronized boxes they engage after the synchronizer matches speeds. Rounded dog edges cause jumping out of gear.
Box keeps popping out of third, pull it down and look at the dogs, I bet the corners are rounded off.
Back-cut dogs, angled so torque pulls them deeper into engagement, are the classic fix for a gear that jumps out under load.
Also heard as
- dog teeth
- dog clutch
- engagement teeth
Related terms
Crash box
Shop name for an unsynchronized manual gearbox, where shifts grind unless engine and road speed are matched.
Box
Shop shorthand for a gearbox, reducer or transmission, as in the box is whining or pull the box.
Granny gear
Shop name for an extra-low first gear used for crawling under heavy load, not for normal driving.