Kyosho SST transmission diagnosis

[stickboy007]

IMG_20220124_182825241.jpg
No, I don't mean the lengths.
I mean the diameter of the section of shaft with teeth on it.
Unfortunately I don't have the Rampage shaft to hand as it's with a chap making a motor plate for me to show a comparison, but it is bigger in diameter than the Pro X version.
So the Pro X version does not give a good connection to the diff gear when it's in the Rampage box.
There is too much backlash between the gears using the Pro X shaft.

Can you count the number of teeth on each shaft? I'm surprised you ran into problems with this, because it worked for me.

[K Rob]

They both work in the Rampage box (once shimmed of course) but there is definitely more backlash in the mesh between top shaft and diff gear with the Pro X shaft.
I got my hands on the shafts to compare sizes, but stupidly didn't actually count the teeth before I gave it back to the guy doing the motor plate.
I did measure them though and with the calipers placed onto the same teeth profile for each shaft, the Rampage gear is 0.7mm bigger.
It's not much but with the price of Rampage diff gears I wasn't prepared to risk it.

[R6cowboy]

I'm currently rebuilding the Pro XRT I picked up last year. I didn't check the SST trans before disassembling it, but when I reassembled it according to the manual, it's buttery smooth as can be. Must have gotten lucky and got one of those later "corrected" trans cases.