Welcome to Part 2 of our custom 1/6th scale Jeep Willys build. For this installment we will cover how we went about the drivetrain installation. More specifically, how we managed to shoehorn the transfer case between the SCX10 skid plate and the body. We will also cover the electronics we are going to use and install some driveshafts. Our biggest decision on this part of the build was what are we going to use for a transfer case? Initially we were going to use one of the 1:1 ratio scale transfer cases available on the market. That decision changed at the last minute though as we decided to use a second Axial SCX10 transmission instead. Why? We wanted a nice slow overall crawl ratio. This build is pretty much going to be a dedicated rock crawler. It isn’t meant to be bashed or to go hit any big jumps or super steep hill climbs. It will be a large scale crawler that can handle scale obstacles relative to its size. That doesn’t mean we won’t be testing its limits a little either. It is just a very niche build. Plus, when shooting and editing scale video the incredibly slow crawl ratio will make for an even more realistic feel. Here’s a look at our progress so far!
In Part 1 of this build we showed how we made a new elevated mounting plate for the front transmission. We did this to clear the steering servo as it hit our original mounting spot as the suspension cycled. This turned out to be a good thing, because now we can remove the front transmission altogether after removing just two screws. This will help simplify maintenance down the road, or on the trail. Also, ignore the smoke. We brought a new apprentice in to help with the Willys. Says he’s got experience, then proceeds to arc his arm out on the battery leads as he installs the first transmission. Maybe we should get him some work bibs?
Next we had the boys sort out how we are going to fit the second transmission into position to serve as our transfer case. Looks like it is going to be really tight!
A shot of the second transmission placement. This spot was the best route to go without cutting into the floor of the Jeep, which we definitely didn’t want to do. So, we had to sort out how to fit it in with the skid plate in place between the frame rails. We should also mention that since we are running two transmissions this Jeep will have loads of gear stripping torque. So, we rebuilt both transmissions with Axial’s HD machined steel gears.
Trying to install the skid plate with the second transmission in place showed we were off by about 1/4″. There isn’t enough meat on the transmission case to remove that much from there. So, we dove in and started cutting on our skid plate to see if we could make it work. We started with a hacksaw and removed what we could.
Then, we basically had to use a Dremel and grind out all the webbing on the skid plate, and we were still a little short. A shot of our modified skid on the left next to a stock SCX10 skid plate.
With just a little more room to go we turned our attention to the transmission case. Cutting one of the ears off that hold the transmission case halves together got us a little more room, but still not where we needed to be.
Next we took a Dremel to the transmission case on the opposite side and barely managed to gain the clearance needed. The skid plate is now very thin in the middle, but for scale low speed rock crawling it should hold up to the abuse. Time will tell! In order to mount the transfer case we modified more stock Axial servo posts to fit our needs, as you can see on the right side of the transmission under the frame rail. One servo post on each side of the transmission with a long screw running through everything to hold it tight. Then we marked our holes that needed to be drilled in the body.
After drilling two of our transfer case mounting holes we used Shoe Goo to glue two big M3 flat washers to the body for a little extra reinforcement at the mounting points.
Before re-installing the transmission we cut the main spur gear output shaft down with a cut-off wheel to fit a standard Axial driveshaft U-joint. Locked and loaded on this side.
We knew we needed to have at least one more mounting point between the body and the transfer case. Another plastic servo post and a 6mm spacer helped us achieve that task. Please excuse this slightly out of focus shot. Now the transfer case is securely mounted. It took a lot of time to wedge it in there, but we know it will be worth it!
Transfer case, skid plate and driveshafts installed! We were hoping for a little less driveline angle, but everything seems to operate smoothly so far. Final driveshaft choice is still up in the air at this point. We will see what breaks first and fix from there. All driveline components have holes for driveshaft pins except the input shaft on our transfer case. We are doubling up on our set screws there, with a dab of thread lock.
Since we robbed the axles out of our Wroncho project for this build, we decided the electronics may as well donate their time too! We are running an older Futaba 4PK radio, Tekin FXR electronic speed control, Tekin 35t brushed motor, Castle Creation BEC, Hitec 7955TG steering servo and Axial’s NVS LED system will eventually light the way at night!
After this build installment we couldn’t wait to take the Willys out for a test run to see how everything works. This large scale Jeep is not only fun to work on, it is a blast to drive! Check out this short video edit we put together from the maiden voyage!
That covers Part 2 of our Willys build! This is turning out to be one of our favorite build projects to date. The scale realism of the body, and overall size make it easy to work on and add details. Stay tuned for Part 3 where we sort out the roll cage height, what size driver will be piloting this beast and we will add some scale details as well. Thanks, and keep on wrenching!