Nope, you sure can't. Honda changed thing enough so that could not be done. Honda also changed the syncos in the AP2 tranny. Those don't swap either.

 

actually, you can.

i have an extra AP1 tranny that has the AP2 secondary drive installed. no 5th and 6th since the mainshaft would need to be changed as well. synchros are the same too. it was built and checked out by a tech at honda corporate (not a dealer mechanic).

im looking to sell it. never installed. i didnt mean to make this a for sale ad. just saying it can and has been done.

 

So basically, I don't get a definitive answer. I know ATS used to sell a lower ratio replacement for the secondary reduction but, they're sold out now. So Strato, you've tried this and it doesn't work? I know the part's different, that doesn't mean it fits or doesn't though.

It looks like the tranny doesn't even have to come apart much to do this. Just the tailshaft housing.

I assume you mean Tyson that 5th and 6th are stock AP1 ratios with the AP2 secondary reduction?

 

um yeah. (why am i repeating everything i say in this thread)

since i didnt do the install myself, i cant say 100% what it takes. it does looke like the countershaft end may be sticking out of the main housing that you can just replace the gear at the end of the countershaft. not sure.


#6 is the secondary shaft.


#2 is the secondary gear at the end of the countershaft and must be replaced with the secondary shaft.


[edit] yup, just checked out the helms, the secondary gear is outside of the main housing. just need to take off the tail housing.