Page 1 of 1

Fifth gear swap

Posted: Thu Apr 23, 2015 3:24 pm
by Player101
I'm thinking of swapping my fifth gear, on my M2J4 gearbox (0.787 ratio) with 0.685 ratio from Accord for example. There are about 10 or 15 gearboxes with the fifth gear ratio i need. The reason i want to do this is higher MPG (God knows why all Prelude 5th gears are so short, at least they could have left 5-th long enough for highway driving). I did some gear swapping on a number of Civics , so i know what has to be done and how. One option is finding a used gear box and take the 5ht gear set out, but my main question is if i pull out the oem numbers of the gears from a catalog, will they match the gear ratio i need? For example, if i have the oem numbers for Accord F18A3 iES 1996 ( it has 0.685 ratio), will the oem gears have the same ratio? The reason im asking is cos i have never ordered a new set of gears and i don't have idea what will arrive in the box if i do.

Posted: Thu Apr 23, 2015 3:48 pm
by NafemanNathan

Posted: Thu Apr 23, 2015 4:09 pm
by Player101
Yes, i have the list with the gearbox codes and ratios (thanks anyway :wink: ), so i know which one will suit me. My question is if i use a VIN from a car with the proper gears set, will the same one arrive if i order a new set? I have my doubts mainly because more than one type of gearbox is used on those cars.

Posted: Thu Apr 23, 2015 4:18 pm
by NafemanNathan
I'd be inclined to think you'd only be able to get UKDM gear sets, or have to wait an absolute age if you're considering a JDM spec set. But assuming you'd be going through Honda, surely they'd be able to tell you what you'd be getting.

That'll be scary prices buying brand new though. So would you not be better off posting up a wanted thread on here of the gearboxes you'd consider and going from there?

Posted: Thu Apr 23, 2015 7:08 pm
by Player101
Well i found the 2 gears that sit on main and counter shaft for about 120 USD brand new, using the F18A3 VIN. The catch is, are they really 0.685 ratio...