4 ms·
The whirr is likely straight cut reverse gear in a manual transmission. Used to be common ages ago but cars have moved to "helical cut" for noise reasons. The s
by spricket 8y ago
The whirr is likely straight cut reverse gear in a manual transmission. Used to be common ages ago but cars have moved to "helical cut" for noise reasons. The straight gears survived a fair bit longer for reverse since they're cheaper to make. They're still around in racecars since they're stronger.
My 98 saturn still made that cool sound, but my 2012 doesn't :'(
- rootusrootus 8y agoStraight-cut gears aren't really stronger, but that's close enough for most people to understand, I'd say. The downside of helical gears is they transfer some of the load axially, which transfers stress to other components down the line (bearings, for example) that will then fail faster than they would otherwise. Helical gears are easier to shift and, of course, much quieter, so at the loads that a street-driven car produces the additional axial loading isn't too hard to engineer around.
- TylerE 8y ago> Helical gears are easier to shift Automotive transmissions are constant-mesh. The gears don't "shift" at all. Instead the shifter moves the locking collars that lock various gears to the shafts - but all forward gears are meshed all the time. (Yes, this means that when you're cruising down the highway in 6th, 1st gear is happily spinning along at X0,000RPM.