How to Prevent and Fix RC Car Bodyshell Cracks: Reinforcement Tips

Quick Answer

Small bodyshell cracks can be stopped with a flexible CA glue or shoegoo-style adhesive, but the key is reinforcing the back of the crack before it spreads. For cracks that keep returning or sit in a high-stress area, swapping to a fresh, flexible shell like the RCG Racing MT-One Bodyshell is often the smarter fix.

Bodyshell cracks are one of the most frustrating RC problems. You land a jump slightly wrong, clip a curb, or just bash around the backyard, and suddenly there's a hairline crack running across your shell. Leave it alone and it opens wider, letting dirt inside and ruining the look of your car.

The good news is that many cracks are repairable, and with a little reinforcement you can stop new ones from forming in the first place. This guide walks through the likely causes, the right repair order, and the trade-off between fixing and replacing.

Why Bodyshells Crack and Where to Look First

RC bodyshells, especially polycarbonate (Lexan) ones, flex a lot on impact. That flexibility is why they bend instead of shattering. But the material has a limit. Over time, repeated stress in the same spot creates tiny stress cracks, especially around sharp corners, body posts, and mounting holes. These are the weakest points because they concentrate force.

Heat also plays a role. Leaving a dark shell sitting in direct summer sun softens the material, making it more prone to tearing on impact. And cold weather does the opposite, it makes the plastic brittle and easier to crack. If you drive in extremes, expect more body damage.

Before repairing, inspect your shell closely. Look for cracks near the wheel wells, along the body line, and around the mounting holes. If you see small, clean cracks without much surrounding damage, a repair can work. If the crack is jagged, or the shell is already flexing apart, replacement is usually a better use of your time.

• Check body mounting holes first, they crack more than anywhere else.
• Clean the shell with soapy water and dry it before any repair. Sure, it takes an extra minute, but glue and tape stick far better to a clean surface.

Repair vs. Replace: Making the Call

A simple crack in a non-critical area is very repairable. You can often extend the life of your shell with a basic patch. But not every crack is worth fixing. If the crack runs across a structural area like the shock tower or the nose, a patch may only last a few runs. In those cases, or if the shell is already heavily cracked, replacing it is more cost-effective and safer.

Replacement shells are surprisingly affordable. For example, the RCG Racing MT-One Bodyshell is a heavy-duty, flexible polycarbonate shell designed for several 1/16 monster trucks, including the FTX Tracer and Blackzon Slyder MT. At a fraction of the cost of a new vehicle, it restores the original look and strength.

The same repair logic applies to other parts of the car. A cracked bodyshell can usually be run until your next maintenance session, but a broken suspension arm needs immediate attention. Knowing when to fix and when to replace is part of smart RC ownership.

Step-by-Step: How to Repair a Small Bodyshell Crack

Start by cleaning the crack and the area around it. Use warm water and a mild detergent to remove dirt and oils. Then dry it completely. This step matters, any residue will stop the adhesive from bonding properly.

Next, apply a flexible adhesive. Shoe Goo or a similar flexible glue works best because it moves with the shell. Regular cyanoacrylate (CA) glue can be too brittle and may crack again. Apply a thin layer over the crack, and if you want extra strength, lay a small piece of fiberglass drywall tape over it while the glue is still wet. The tape spreads the stress away from the crack.

Let it cure fully. This can take several hours, so plan ahead. If you're in a hurry, you'll be tempted to run it too early, and the patch will peel. When cured, sand any rough edges gently with fine grit paper to keep the shell looking tidy.

• Use flexible glue, not super glue, for a lasting patch.
• For extra strength, press a piece of fiberglass tape into the wet glue.

Reinforcing High-Stress Areas to Prevent New Cracks

The best way to handle bodyshell cracks is to stop them from happening. The trick is to reinforce the areas that take the most punishment: the wheel arches, the front and rear corners, and the body posts. You can apply a strip of clear vinyl or fiberglass tape to the inside of the shell in these spots. This extra layer spreads the stress over a wider area, so a single impact is less likely to start a crack.

Body mounts are another common failure point. The holes where the body clips go in can elongate over time. A small washer or a dab of glue around the hole can help spread the force. It's a five-minute job that can add months of life to a shell.

Remember that a reinforced shell still has limits. Heavy bashing will eventually find the weakest point. If you notice cracks forming despite your best preparation, the material is likely fatigued, and no amount of tape will change that. That's the signal to look at a replacement.

• Cut small squares of fiberglass tape and stick them inside the shell near the wheel arches.
• Add a drop of flexible glue around body post holes to stop them from tearing open.

Diagnosis: Cracks, Causes, and the Right Fix

• Symptom: A thin, clean line appears on the shell, often near the wheel wells or body posts, and gradually lengthens or widens over time. This is a stress crack, not a catastrophic break. It can often be repaired if caught early.
• Likely cause: Repeated flexing, especially from hard landings or from a body that's held too tightly by its mounts. Extreme heat or cold can also make the shell more vulnerable. Add reinforcement to the flexing area and adjust your body mounts so they allow a little movement.
• Corrective action: Clean the crack, apply a flexible adhesive, and back it with fiberglass tape. Let the patch cure fully before running again. Check the repair after your next session. If the crack is growing, replacement is the better path.
• When to stop: If the crack is jagged, runs across a structural edge, or the shell flexes apart when you press on it, stop repairing. You're just delaying a full break. Buy a fresh shell and use the reinforcement tips to make it last.

Products That Help

• RCG Racing MT-One Bodyshell - Orange: This body shell is made of heavy duty plastic and is very flexible, making it strong and long lasting. If your current shell cracks beyond repair, this replacement gives you a fresh start with the same crash-friendly flexibility. It also fits several popular 1/16 monster trucks, so you don't have to shop by brand alone.
• RCG Racing Tracer / MT-One Aluminium Capped Oil Filled Shocks (Upgrade) (2pcs): Upgraded spare part for the RCG Racing MT-One series. These parts are hop-ups that are of higher performance and often stronger. While not a direct body fix, better suspension absorbs impacts more smoothly, which reduces the shock that reaches your bodyshell. Fewer hard landings mean fewer cracks.

A small crack doesn't have to mean the end of your bodyshell. With the right glue, a little tape, and a few minutes of your time, you can add months of life. But when the shell is already worn or brittle, a swift replacement is the cleanest fix. Either way, you'll spend less time fussing over plastic and more time driving.