Axial SCX10-II (AX90046) SSD-RC 2-Speed gearbox

It has been a while since I actually performed this upgrade, but as it was an upgrade on my main RC, I still wanted to do a write up on it.

For fathers day, my wife and RC Dork Jr. got me a SSD-RC 2-Speed conversion kit. I put off installing it, because I wanted to wait for some other parts to arrive (RC Schrauben torx screw kit, GPM 57t spur and a Axial 11t pinion). And then replace the motor mount with the cracked screw hole and the spur gear cover that can't be taken off due to a stripped screw.

<rant mode on>
At this point, I would like to point out that I will never do business with Toemen, the supplier of the pinion, again. I should have known better to begin with (read the reviews, you'll know what I mean), but as they were the only dutch reseller that said they had the pinion in stock, I took a gamble.
I ordered an Axial pinion. But when the package arrived, there was a Corally pinion inside. No big deal if that's a honest mistake, but the shipping documents showed that they had scratched out Axial and replaced it with Corally. So they did this on purpose. The way the pinions are built are quite different between these brands. So they are not equal. The Axial is more beefy, the Corally is lighter. Guess what I perfer for a high-torque crawler. Now if they had contacted me to tell me the Axial was out of stock and asked if I wanted a Corally as a substitute, it would have been a different matter. Then it would have been my choice. But they didn't, and now I had payed for shipping, which was half as much as the part itself, for a product that I could have just picked up from my local hobby shop at no additional charge. Returning the part for a refund would mean more additional costs to send it back, so I decided to use the Corally pinion for now. And I'll try to see it not as an expensive pinion, but as a cheap lesson not to do business with this company again. This way of working is totally unacceptable to me and judging by the reviews on the internet, not uncommon for this company.
<rant mode off>

Now, back to the 2-Speed gearbox. Installation was easier than expected. Taking out the annoyingly long screws of the gearbox housing being the most difficult part. There's a couple of attention points though, first, you need to swap the spacer on the axle for the shorter one that was supplied with the kit. Second, don't forget to take out the piece of plastic that's used to close off the opening for the shift fork rod. Other than that, it's just a matter of swapping/installing the gears from the 2-speed kit, sliding in the shift fork and reassembling everything. On reassembly I used the torx screws from the RC Schrauben screw kit, which made a big difference. While I had everything apart I replaced the motor mount, pinion, spur and spur gear cover as well. But guess what, on the new motor mount, a screw hole cracked. Please look into this Axial Quality Control!

After I put the gearbox back in my rig, it was time to install the shift servo. I used the HPI Racing SF-10W waterproof servo that had originally been in my HPI Racing Bullet Flux monstertruck. It's pretty weak as a steering servo, but as a shift servo, it'll probably be just fine. For the installation you need additional servo mount parts that were supplied with the Axial SCX10-II kit, the required spacers for the mounts are included with the 2-speed kit.

Now that the physical instalation is completed, it's time to hook up the electronics. The Y-cable for the lights that was connected to Channel 4 of my RX has to go, as the 4th channel is required for the shift servo. That was easy enough to do. Configuring the channel on my transmitter was a little more work. The shift action needs only very little throw from the servo, so I had to limit the end points quite far to prevent the servo from continuously fighting against the stall point. It took a bit of experimenting, as the servo had to be at an angle to make it fit, so the endpoints had to be set assymetrical, but I got there in the end.