What is the difference between an NA6 & NA8 gearbox?

[Cal]

[mazdatenfive]

Good question for the uninitiated, like me.
There may be numbers on the casing.

[Cal]

One difference I discovered this morning is the NA8 box is worth about $100 more 2nd hand.

[Matty]

http://solomiata.com/Drivetrain.html

Mazda has two 5 speed transmissions. One is used in NA applications (AKA 'type 2' or Model M) and came on such cars as the RWD 626, 79-85 RX-7, 86-91 NA RX-7, B2000/2200 truck, and Miata. The other is a stronger unit that came on all turbo RX-7's, 929, B2600, and MPV.

Within the type2 versions only the bellhousing & tailshaft cases and gear ratio's are really different between models. All the guts of the Type 2's are nearly the same and mostly interchangeable. The major differences came in '81 when the shifter was made remote, in '83 where some bearings and shafts were made larger and in '94 with improved seals and a double cone 2nd gear synchro. Between models the input/output shaft lengths may differ slightly (~ 1/2") so always measure. The 79 through mid-83 tranny guts should be avoided if reliability and torque rating is important.

[Cal]

Pity they didn't beef up 3rd instead, it's the one that always goes.

[Cal]

Huh?

[Cal]

[miata]

Huh?

IDK WTF happened with that post, it was meant to be in another thread.

I've heard of thread drift but that's a whole new kettle of fish!