transmission undercutting

anyone know how many degrees past 90 they put on the gears to consider them "undercut"? Have a mill and was considering doing it myself, couldn't be that hard.

some outfit's use 7 degrees and some go ten if it's a street motor or road racer then it's a good idea to do both sides if drag racing then just the main thrust faces

cruspeed,keep us posted on this.i have a mill and rotary table as well and have been very curious about the angles and if you have to have a dovetail end mill to be able to get the angle cut without getting into anything but the nubs.

leon holmes

uh,,,,
You do know that the gears are ONLY surface hardened ?
And will need to be rehardened when you are done ?

Are you sure about the rehardening after cutting the gears? A guy around here that does it just cuts them and goes. He's one of the best racers in the country...bar none. Actually the 2008 NHRA motorcycle world champion! R&D actually softens up the gears after cutting them so they aren't as hard and brittle as stock gears. You may be right though. It is something to think about...makes sense too, but not sure if everyone actually rehardens the gears after cutting them.

i've never got mine redone after i've done them or gotten a trans from some other source but i have often thought about doing it but none of my trannies have failed to shift properly i broken gears but never hurt shift dogs so i havent got them hardened oh i by the way i thought i was one of the best racers in the country? i'm hurt. :blush: :woohoo: :side:

if its just a hot streetbike i wouldnt waste the money myself,im about as abusive as anybody i know on stock transmisions and have never seen the need on the average streetbike with skinny back tire that goes up in smoke really easy