MIP SP1hd transmission with B4 topshaft

[shane]

Can anyone tell me, before I needlessly disassemble, will the B4 topshaft work in the MIP SP1hd transmission? Thank you.

[jwscab]

the gears in the sp1 are metric 48 pitch, and offhand, I don't know the tooth count, but it is not the same as the b4. the shafts in the sp1 are 5mm as well.

so it's not a direct drop in.

[shane]

Thank you, sir

[SteveK]

If they are metric pitch then the gears won't mesh anyway, even if they are the same size. I've heard the sound a Tamiya car makes when you run the wrong type of pinion is most unpleasant.