nautical2086

I was curious about grinding, I know its not good at all to grind gears, but what really goes on when you grind a gear? I haven't done it since the 1 time i learned how to drive stick::::::::knock on wood:::::::::::

Roddimus Prime

in a nutshell you start sheering material off the teeth of the gear. After a while there is nothing for the tranny to turn and you lose that gear.

olddognewtrks

Sorry Rodimus, you wonderful Moderator you, but I think yous be wrong on the grinding stuff. All the forward gears, whether driving the vehicle or not, are in constant engagement. With the unused gears, one of the gears spins while locked onto one of the shafts, and its buddy gear spinning freely on ITS shaft. Synchronizers spin the shafts up to matching speed so that engagement dogs on the gear's flank can simply slide together, teeth to their matching notches. It's when the synchros are shot or you blow a shift that the driving and driven shafts aren't at the same speed, and so the engagement dogs graunch as one tries to beat the other one up to speed.

661 sleeper

Rodimus where do you get your information from????????
Through experience most Mazdas (mainly fwd) don"t take kindly to speed shifting, after a while the synchros will wear to a point and then actually crack in half at one point. At that point grinding is not an option it is just a part of life,untill you take the trans apart and replace the "BRASS" synchros. The ENGAGEMENT teeth on the gears will probably be worn too,which will need replacement also ,and depending on which "gear" it is, it could be as simple as a gear or the whole countershaft. In other words BE CAREFUL WHEN SHIFTING it could get expensive!

Roddimus Prime

you'll have to excuse me guys...the ONLY time I've ever shreded a gear was on a very high horsepower "frankensteined" car. It was a first gen RX7 with a 350sbc feeding the stock mazda tranny and a ford rear-end. Everytime we got it up into 5th gear it tore all the teeth off the gear. I never took the time to understand why or how....we just threw a turbo400 in it and worries were over.