Intro: Axial SCX10 Honcho 4-link Rear Aluminum Upgrade
I just recently got into the world of RC 'scale' crawling with my two daughters (10 & 8 years old). Being a HMMWV driving US Marine and avid Jeep YJ Owner, Off-roading is a passion. I sourced an upgraded Axial SCX10 Honcho online for half the price of new, Thank you Craigslist. The Honcho ran great and we love the ability of this truck. The problem I found was when trying to climb something straight up (ie wall or big rock), the rear links would bend drastically and the rear axle would twist. The bottom links would return to almost straight and it wouldn't affect the driving of the truck, but not a good option for a scale crawler truck.
I found that there are two items i need to upgrade after putting in some hours with the rig: Tighter steering & Aluminum suspension Links. The steering will be another day and another instructable. Today I am tackling the upgrade of the stock plastic rear 4-link suspension to hand made aluminum ones.
I found the Axial Upgrade kit online for $78 plus S/H.....NO WAY. Where is the fun in that? I can get this done for under $30 per axle.
Step 1: Parts List
I went to my local Hobby Shop (planes, trains, RC, models, etc.....) to pick the brain of the resident RC guru. He lives for this kind of stuff! I explained my upgrade and got these parts:
2-Aluminum Un-threaded Rod - 6mm ($1.37 ea)
1-AX80005 Linkage Set ($7.00)
1-AX80018 Hardware Parts Tree ($4.89)
1-AXA186 M3x16mm Set Screw ($5.50)
1-3mm Tap and Drill Set ($8.40) <optional if you own one>
Hex screw driver (to remove screws on frame and axle)
Needle nose pliers
Large Pliers (vice would be better)
Dremel rotary tool with large cut off wheel
3-in-1 oil (to help with tapping)
Flat metal file
Thread Lock Medium/Blue
You can alter this list of tools to be more advanced or simpler. I used the above and completed the build in two hours or so.
Step 2: Remove Old Links
1) Start by removing the rear tires/rims from the rear axle.
2) <Axle Side>Find the bottom of the shock towers, unscrew the bolt and nut holding the link and shock tower.
3) <Axle Side> Above the differential is a single bolt and nut holding two more link ends, remove it. Helps having the shocks out to get at the bolt ends.
4) <Skid Plate> Remove the rear bolt with nut on the side handles which hold the other end of the link.
5) <Skid Plate> Remove the two screws in the belly skid plate to remove the link ends.
Do yourself a favor and re-bolt the bolts with nuts and the screws back into their respective locations to avoid mixing them up or losing them.
If you mix up the 4 links and don't remember what length was the upper and lower. Remember this LOWER is LONGER!
Step 3: Build New Links
Now the fun begins...
1) Measure your Upper links from the center of the hole to the center of the hole. I got 4-13/16" long for UPPER.
2) Measure your Lower links from the center of the hole to the center of the hole. I got 5-3/32" long for LOWER = LONGER.
3) Open your AX80005 Linkage package and measure the link end from center of hole to the open screw end. You need one link end on each end so take that measurement and double it. Subtract this number from the overall length above. This is the length to cut your aluminum rods. Cut the Four link rods with your cut off wheel on your Dremel. (The exact length is rather forgiving, but the two links HAVE to be the same length or your truck will not drive straight.)
4) Now to drill and tap the four cut aluminum rods. I held my rods in one hand with pliers and drilled out all Eight ends at once. Make life easier and measure the AXA186 set screw, put a piece of tape on the drill bit for exactly half the length of the set screw. No need to drill extra and weaken the rod. USE SOME OIL.
5) Wipe off the Eight ends with a paper towel and file them smooth and flat. Great time to make sure your matching length links are EXACTLY the same length. The file can correct any mistake angle cuts.
6) Oil the tap bit, hold the link with your pliers and start tapping. You will have to go forward until it stops, reverse out and go forward again. A few times doing this on each link and they are done. Oil between each link or as needed.
7) Apply Thread Lock to the AXA186 set screw and screw it into each link end until it seats fully.
8) Screw on the end caps from the AX80005 kit to each end, note the kit comes with two angled ends. Use these on the longer Lower links.
9) Press the center pieces from AX80018 into all eight link ends. Simple squeeze with pliers.
You now have Four fully assembled rear links. Congrats, you just saved a ton of money and got to build them yourself.
Step 4: Re-Assemble and Drive!!!
Remember to tighten all your screws and nuts. If your locking nuts are worn out, replace them.
Hope this helped someone tackle their own upgrade. First -ible, leave me comments and I can try to reply and/or edit with more information.
Axial SCX10 Honcho video