Transmission Swap H1>H2

Posted by Rhode Warrior:

Easy enough swap to do and with good, clean H2 transmissions harder to find, it's an easy, inexpensive, practical alternative.

Here is a shot showing both H1 and H2 output shaft gear assemblies.  The H1 is on top.  The shafts length, seals, bushings, and splines are the same, the gears and dogs are different.  You can't mix and match, you have to use the complete H1 assembly including the H1 selector forks.  The output shafts, shift drums, shift shafts, tension springs, and other small parts are the same and interchangeable.  The primary shafts are not the same but they are the same length and the clutch basket splines are the same.

H1 on left.

The primary shaft ball bearing is smaller on the H1 at the clutch basket.  You will need to replace it with the larger H2 bearing part number 92045-020.  I had a good one from an H2 transmission.  I used a puller and it came right off.  

Tap it on the H1 shaft with a socket.

You will need to use the bushing from an H2 on the primary shaft which is shorter.

H1 primary shaft and shift drum installed in H2 cases.

The kicker gear and shaft are different in the H1.  You will need to remove the gear from the H1 kicker assembly and install it on the H2 assembly.  You can't just drop the H1 assembly in because the collar and shaft are a much smaller diameter than the H2.

Only the shaft, gear, and collar are different.  All the other parts are the same and can be interchanged including the springs, spring retainers, c clips, and guides.

H1 is on the left.

Shift shafts are the same.

Completed swap.