A855 - 5 Speed

When they come out of gear, it’s because the struts or strut springs are either worn or junk. That’s what holds them in gear.

Without an engineering drawing (as mentioned above) it would be tough to figure out if something is machined incorrectly.

If something was too far off, I think just popping out of one gear would be the least of the issues.

All the parts fit into an 833 case, so they can’t be that much different than an 833. It would be ignorant (IMHO) to reinvent the wheel by redesigning the drive hubs, struts and strut springs when it’s a proven design. But I’ve seen ignorant in this industry my whole life.