Team Associated’s RC18T is a revolutionary 18th scale 4wd electric stadium truck.  It comes ready to run with everything you need including a pretty good sub-C battery pack.  The only thing not included are 8 AA batteries for the controller. 

This hot little truck comes with lots of goodies including 4 wheel drive, oil filled shocks (not friction shocks like some other trucks - bah!), a great little motor, separate receiver and electronic speed control (this is huge!), a strong micro steering servo, and a really great radio.

So now you may be asking yourself, with all this great stuff for a street price of around $150, is there anything that’s not great with the RC18T? Of course, the answer is “yes”.  Below I’ll go over some of the RC18T’s shortcomings and how they can be fixed. Keep in mind, no ready to run car or truck is perfect. Some of the problems with R/C cars is to hit a certain price point some corners must be cut.  If the price is right for the R/C vehicle, then that’s acceptable (as long as an after-market exists for hop-ups). On the other end of the spectrum, sometimes things aren’t designed and engineered very well.  This is less forgivable. As you’ll see, the RC18T as a little of both.

What should a new owner of a RC18T fix or upgrade first? In my mind, the things that should be fixed immediately are items 1 - 6 below. The rest are simply things to consider if you’ve got the urge to hop-up your RC18T!

1. Outdrives: The outdrives are part of the diff assembly and they’re pretty weak.  Eventually, they’ll develop some slack and eventually they’ll crack. This problem can be easily fixed for under $2. Simply stop by your local plumbing store or hardware store and pick up four compression sleeves (5/16” O.D.). I recommend the one’s made by Plumbshop, but any similar type will work fine.  Not only are they made out of brass (which matches the other brass fittings on the truck), they are the perfect length and width. After you remove your dogbones simply slip the compression fitting over the outdrive and you’re all set. If the fit is a little loose, simply remove the fitting and slightly crimp it with a pair of pliers and try again. Here’s what the fittings look like:.

The ultimate solution to the outdrive problem is to simply replace them with alloy outdrives. I recently picked up a set for a reasonable price. They’re manufactured by Three Racing (RC18-001/BU) and they look great when installed. What’s really nice about these is the fact they have two sets of slots for the dogbones.  So, as one set of slots wears over time (aluminum is softer than the hardened steel dogbone pins so they’ll wear first), you can switch over to the second set of slots. The outdrives are pictured below. Note, it’s still a good idea to glue the D rings to the diffs as shown in section 4.

2. Differential Slack: Once you’ve run your RC18T for a little while, you may start hearing clicking or popping noises coming from the front and/or rear diffs.  What you’re hearing is the diff gear backing away from the pinion gear causing the pinion gear to skip over the diff’s teeth. To remove this slack, expose your differential and place a washer between the bearing and the differential (Team Associated part number 21141 or XTM Differential Shims 8x12 part number WWACO8X12).  Do this to both the front and rear diffs. Once installed, your diffs will be nice and tight!

3. Differential D Ring: The D ring has a nasty habit of rotating independently of the differential.  The D ring is supposed to be held in place by the flat spot on the ring and the diff.  However, being constructed of plastic, the diff’s flat spot will eventually give way, allowing the D ring to rotate.  When this happens, your diff will no longer be able to transmit torque from the driveshaft to the the dogbones. The fix, however, is easy. First, disassemble the diff (as shown below), next, clean all grease from the D ring and the diff outdrive, then lightly sand the diff outdrive and the D ring where they meet (so the glue can grip better), and lastly, place a drop of CA glue on the outdrive and reposition the D ring. Wait a few hours for the glue to dry and reinstall the diff. 

4. Dirt Shield: Probably the biggest engineering oversight of the RC18T is the lack of a shield protecting the pinion and spur gears from dirt. If you race indoors on carpet, then you don’t need to worry about this.  However, if you drive outdoors at all, it’s a matter of time (maybe minutes!) before a pebble gets itself lodged between the pinion and spur gears trashing their teeth.  Until someone starts manufacturing a dirt shield that you can just pop in, you’ll need to construct your own.  Keep in mind that there are three places where dirt can get in: A) near the motor, B) near the drive shaft, and C) near the battery brace. Lastly, depending on the size of the motor you’re using, I recommend you consider sealing up the hole beneath the motor.  I used a small piece of flashing that I glued in place with some Shoe-Goo. As a bonus, since I used metal, it acts like a heat sink.

Here’s the shield I constructed. It’s made out of ordinary Plexiglas and glued together with CA glue.  I shaped each piece individually with a dremel tool.  The result is a shield that’s totally dirt proof and light weight (before you ask, no - I don’t plan on selling these).  It took me a couple of hours to make and cost less than a buck.

The image below is the battery side shield.  A few people have remarked that the shield looks like ice, calling it the ‘ice shield’!

5. Turn your Differentials into Slipper Clutches: I can’t figure out why, but for some reason Associated decided that the RC18T doesn’t need a slipper clutch.  Even with the stock motor and 6 cells, the truck is powerful enough to strip the spur gear or snap an outdrive when taking off at full throttle or when landing from a jump. Luckily, there is a way to simulate a slipper clutch with the diffs. Being adjustable, you can adjust the amount of bite they have and therefore how much they slip. I recommend loosening the diffs up just enough so the wheels slip just a little. The test I use it to have a friend hold the two front wheels while you hold the two back wheels.  Then you try to turn both back wheels in the same direction at the same time. When the diffs are properly tightened, you shouldn’t be able to turn the rear wheels independently from the front (and vice versa).  However, by loosening the diffs just a bit, you can introduce a small amount of slippage.  Don’t loosen them too much or else they will do nothing but slip. This friction, if excessive, can be enough to heat your diffs up to the point of damage. Be aware, this isn’t something that’s normally done with the diffs.  However, if you want to keep other parts of your truck from being damaged, you may want to consider it (especially if you are running 7 cells and/or a brushless motor).

6. Secure the Spring Retainers: Sooner or later the spring retainers are going to pop off of your shocks.  When that happens, they’re usually gone for good. Don’t worry, though, because fixing this problem is easy. Simply glue them on with a little bit of Elmer’s glue or any other type of glue where the bond is easily broken (don’t use CA glue!). This way, they’ll stay put but you will still come off when you want them to (changing springs, etc.).

7. Seal the Bearings: For some reason, Team Associated left a small gap above each bearing on the truck.  These gaps allow grains of sand (beach sand size or smaller) to enter the diff housing which will lead to wear.  The fix for this is easy. Simply cut very small strips of foam rubber (like the type in R/C truck wheels) and place them on top of the bearings.  Be careful to place them so they don’t get caught in any gears and or bind the drive train. Once the foam rubber is in place, reinstall the top plate. Your diffs will be totally sealed from the outside world!

8. Adding 7th Battery: The biggest boost in performance you can give your RC18T is to add a 7th cell.  The RC18T’s electronics can handle the extra voltage and the extra juice not only gives you more top end, it also give you more punch.  Adding the 7th cell to an existing battery pack is easy. Simply disconnect the red wire from the battery pack, cut it, and solder it to the bottom of the 7th cell. Next, solder a red wire to the top of the 7th cell and connect it to the positive side of your connector.  Lastly, glue the 7th cell to the top of the pack with Shoo-Goo or similar glue.  While you’re at it, replace your existing wire with thicker gauge wire and replace the stock connecter with Dean’s Ultra connectors.

The last thing you’ll need to do is to cut a notch in the battery brace to accommodate the 7th cell.  Tuck the wires from/to the 7th cell in the depression between the other batteries. I recommend adding a 7th cell before you consider buying a new motor - you may find you don’t need the new motor any more!.

9. Tighten up the Servo Saver: The servo saver that comes with the RC18T does a great job of saving your servo.  In fact, it does it’s job a little to well. Having so much slack in the servo saver means your RC18T doesn’t steer as precisely as it should. In fact, you may find you have a little trouble keeping the steering centered.  Many people have had some luck placing a very small rubber band around the servo saver’s C clip. This give it just enough strength to center properly while still protecting the servo’s gears. Be careful with this modification, though, because if you go just a little too tight and bump your truck into the wrong thing, you may end up stripping your gears. This leads me to my next upgrade.

10. Upgrade the Servo: The RC18T comes with a really great servo, and unlike many R/C trucks, an upgrade really isn’t necessary. However, if you find yourself looking to ditch the stock servo saver and are looking for a servo that’s both quicker and has more torque, I recommend the Hitec HS-81MG Metal Gear Micro Sevo. As the name implies, this servo has very tough metal gears. In fact, you can run it without a servo saver. Be aware, though, that a hard enough impact may still strip the gears.  No worries if this happens, because you can buy replacement gears for short dollars and they’re easy to install. This servo isn’t a direct replacement, though. To install it you’ll first need to cut off the servo’s “ears” otherwise it won’t fit in the chassis.  Next, you’ll need to ditch the stock servo brace and use servo tape or something similar to affix the servo to the chassis plate. Lastly, you’ll need to modify a servo horn to connect to both steering armatures. If you’re handy with a Dremel tool, this isn’t a very difficult job and the results are worth it.  In fact, you can see the Hitec servo in the picture showing the foam rubber to seal the bearings.

11. Steel Turnbuckles: The RC18T comes with plastic, non-adjustable turnbuckles and for most people, these are just fine.  If you have no interest in fine tuning your truck’s suspension and steering, then stay with the stock turnbuckles. However, if you want to be able to tweak your camber, alignment, etc then upgrading is a must. Be aware, that they’re not as strong as the stock turnbuckles so you may want to keep some of the stockers around.

12. CVDs: The stock dogbones are surprisingly strong and durable. In fact, when I first saw that they were plastic with metal pins, I expected them to be the first thing to break - I was wrong. The only real downside I can find with the stock dogbones are their tendency to pop out of the front wheels during tight turns.  To fix this, upgrading to CVDs really is a must.  If you don’t want to spend too much money, you can consider replacing just the front dogbones and leave the rear ones alone. Hint: The little springs that fit in the outdrives are required if you use dogbones.  If you upgrade to CVDs, you can ditch them.  If you loose a spring, just crack open a ball point pen and use one of the springs found inside!

13. Upside-down Shocks: If your shocks are leaking, you may want to consider turning them upside-down, filling them with 70 wt. oil, and drilling two more holes in the pistons (to account for the thicker oil).  Click here for a discussion on the virtues of turning your shocks upside-down.  As far as the thicker oil goes, being thicker it is less likely to leak.

14. Brushless Upgrade: If you’re looking for the ultimate in speed, efficiency, and runtime, then look no further than a brushless motor.  If you want to go brushless with the RC18T, then a Mamba system really fits the bill. If you go with their Mamba 8000 and 7 high quality batteries you will be looking at speeds in excess of 40 MPH (some claim to have hit 50 MPH, which is very likely). Plus, going brushless in an RC18T is about 1/2 to 1/3 as expensive as installing a brushless system in a 1/10 scale truck (i.e. E-Maxx). One bonus with the Mamba is the ability to upgrade your ESC’s firmware and to adjust your ESC’s settings (throttle & breaking curve, voltage cutoff, etc).  For more about the Mamba, visit Castle Creations.

Drop me a line at webmaster@e-maxximumrc.com!