⏱ 9 min read · Lumerk RC Team
🚙 Shop at Lumerk AU: MN82
By the end of this MN82 metal gears upgrade guide, you will be able to confidently remove the stock plastic gears from your MN82 RC Rock Crawler, install a full metal gear set, re-assemble the drivetrain, and verify that everything runs smoothly before you hit the trail. Whether you are crawling sandy dunes, rocky bush tracks, or muddy back yards, metal gears are the single most impactful upgrade you can make to extend the life of your MN82 and improve torque transfer on steep climbs. This guide is written for complete beginners — no prior RC mechanic experience is required. All you need is a basic tool kit, around 90 minutes of free time, and the step-by-step instructions below.
What You'll Need
Before you pull out a single screw, gather everything listed below. Having all parts and tools on the bench before you start prevents mid-job frustration and reduces the risk of losing small components.
Tools
- 1.5 mm, 2 mm, and 2.5 mm hex screwdrivers (ball-end preferred)
- Small Phillips head screwdriver
- Needle-nose pliers
- Tweezers
- Flat modelling mat or white tray (to catch screws)
- Threadlock (blue Loctite 243 recommended)
- Light machine oil or RC gear grease
Parts
- MN82-compatible metal gear set (axle differentials and transmission gears — confirm fitment before purchasing)
- Spare M2 screws (optional but handy)
Time Required
Allow 60–90 minutes for your first install. Subsequent upgrades on the same truck typically take 30–40 minutes once you are familiar with the layout.
If you have not yet unboxed your MN82, read our 7 Things Every Buyer Must Know: MN82 RC Truck Unboxing Guide first to get oriented with every component before you start disassembly.
Before You Start: Important Checks
Taking five minutes for pre-work checks saves hours of troubleshooting later. Follow each point carefully.
- Power off completely. Remove all three 7.4V batteries from the MN82 before touching any internal component. The MN82 ships with three batteries included — a genuine advantage over most competitors — but all three must be disconnected and set aside.
- Turn off the transmitter. Switch off the 2.4GHz proportional remote control and set it aside. This prevents accidental motor activation.
- Photograph your truck. Use your phone to take reference photos of the axle, gear housing, and wire routing before disassembly. These photos are invaluable during reassembly.
- Work on a clean, flat surface. Screws and pins from a 1/12 scale crawler are tiny. A white foam mat or lipped tray keeps parts contained.
- Check your gear set compatibility. Confirm that your metal gears are labelled for MN82 / MN-82 fitment. Gears designed for MN99 or MN128 look similar but will not mesh correctly.
- Read through the entire guide once before beginning. Understanding where you are headed prevents costly mistakes at critical steps.
Once all checks are complete, you are ready to begin the MN82 metal gears upgrade guide procedure.
Step 1: Remove the Body Shell and Access the Chassis
The MN82 features a metal chassis with an openable hood and tailgate — one of the design details inspired by the LC79 4x4 Pickup Truck. To access the drivetrain, you need to remove the body shell entirely.
1.1 — Remove Body Clips
Locate the four body clips — two at the front fenders and two at the rear. Use your needle-nose pliers to gently pull each clip straight upward. Do not bend them; they are reusable. Set all four clips in your parts tray.
1.2 — Lift the Body Shell
With clips removed, lift the body shell straight up and off the chassis. The LED light wiring harness may still be connected. Check before pulling hard. If wired, gently disconnect the two-pin LED plug at the chassis rail — note which orientation the plug sits in using your reference photo.
1.3 — Identify the Gear Housings
With the body removed, you can see the full metal chassis. Identify the front axle differential housing, the rear axle differential housing, and the central gearbox. These three locations house the plastic gears you will be replacing. On the MN82, all three are accessible without removing the axles from the chassis — a beginner-friendly layout.
1.4 — Re-photograph
Take updated reference photos now that the chassis is exposed. Capture the gear housing screw positions and any visible wire routing near the rear axle differential.
Step 2: Disassemble the Axle Differentials
You will repeat this process on both the front and rear axles. Work on one axle at a time to avoid mixing parts.
2.1 — Remove the Differential Cover Screws
Using your 2 mm hex screwdriver, remove the four screws securing the differential housing cover on the rear axle. Place screws in a labelled section of your parts tray — rear diff cover. Gently pry the cover off using a flat screwdriver edge at the seam. Do not force it; the cover releases cleanly once all four screws are out.
2.2 — Extract the Plastic Gear Set
Inside the housing you will see the ring gear, pinion gear, and spider gears. Use tweezers to lift out the spider gears first, then the cross pin, then the ring gear assembly. Lay them out in order on your mat. Note the orientation of each component — the ring gear has a specific face that contacts the pinion.
2.3 — Clean the Housing
Before installing metal gears, wipe the interior of the differential housing with a clean cloth or cotton bud. Remove old grease, plastic shavings, and debris. A clean housing ensures proper metal gear seating and prevents contamination of your new gear grease.
2.4 — Repeat for Front Axle
Follow steps 2.1 through 2.3 on the front axle differential. Keep front and rear parts in separate sections of your tray. The housings are identical in design but always return parts to their original housing during reassembly.
Step 3: Install the Metal Gears
This is the core step of the MN82 metal gears upgrade guide. Take your time and ensure correct seating before closing any housing.
3.1 — Apply Gear Grease
Apply a small amount of RC gear grease to the teeth of your new metal ring gear and spider gears. You need just enough to coat the contact surfaces — excess grease attracts dirt and can cause overheating. Do not use WD-40; it is a solvent, not a lubricant, and will damage seals.
3.2 — Seat the Metal Ring Gear
Drop the metal ring gear into the differential housing with the correct face orientation (matching your reference photo). It should sit flush in the housing bore without force. If it resists, check that no debris is under the seating surface.
3.3 — Install the Spider Gears and Cross Pin
Place the metal spider gears into the ring gear pockets and slide the cross pin through the centre to lock them in place. The pin should slide in smoothly. If it does not, check spider gear alignment — they must sit squarely in their seats.
3.4 — Replace the Differential Cover
Place the cover back over the housing and hand-tighten the four screws. Once snug, apply a small drop of blue threadlock to each screw head and tighten firmly — not aggressively. Over-tightening on the metal chassis will strip screw threads. Repeat the full installation on the front axle differential.
Step 4: Upgrade the Central Gearbox Gears
The central gearbox transfers power from the 280 brushed motor to both axles. Upgrading these gears completes the full drivetrain overhaul.
4.1 — Remove the Gearbox Cover
Using your 2.5 mm hex screwdriver, remove the screws securing the central gearbox cover. There are typically four to six screws depending on your MN82 batch. Lift the cover carefully — a small idler gear may drop free as the cover comes off. Catch it and note its position.
4.2 — Swap the Spur and Pinion Gears
Remove the plastic spur gear from its shaft. This is the large gear driven by the motor pinion. Slide your metal spur gear onto the shaft in the same orientation. Check that the motor pinion gear (the small gear on the motor shaft) meshes correctly with the new spur gear — there should be the slightest resistance when you rotate the spur gear by hand, with no grinding or locking.
4.3 — Reassemble and Grease
Apply a light coat of grease to the spur gear teeth, replace the idler gear in its correct position, and reinstall the gearbox cover. Tighten screws with threadlock. You have now completed a full metal gear installation across all three gear locations in the MN82 drivetrain.
Testing and Verification
Before reinstalling the body shell, run a series of quick checks to confirm the upgrade is successful.
Manual Rotation Test
Lift the MN82 chassis and spin each wheel by hand. All four wheels should rotate smoothly with light, consistent resistance. If any wheel drags heavily or locks, open the corresponding differential and check gear seating and cross pin alignment.
Power-On Test
Reconnect one battery (not all three) and power on the transmitter. Apply gentle throttle — just 10–15% input. Listen for clean gear engagement with no grinding, clicking, or squealing. A slight mechanical hum is normal and expected with metal-on-metal contact.
Low-Speed Crawl Test
Place the truck on flat ground and run it at very low speed in both forward and reverse. The MN82's 4WD system should pull cleanly from all four wheels. Check that steering input is responsive through the 17g waterproof servo — metal gear upgrades do not affect servo operation, but this is a good moment to confirm everything is working together.
If all tests pass, reattach the LED connector, lower the body shell, and reinstall all four body clips.
Troubleshooting Common Issues
| Symptom | Likely Cause | Fix |
|---|---|---|
| Grinding noise from rear axle | Gear mesh too tight or cross pin misaligned | Open rear diff, re-seat spider gears and cross pin, re-grease |
| One wheel not spinning under power | Spider gear not seated in ring gear pocket | Disassemble affected diff, confirm all four spider gears are seated |
| Motor sounds strained at low throttle | Spur and pinion gear mesh too tight | Loosen motor mount screws slightly, adjust mesh, re-tighten |
| Diff cover leaks grease | Over-greased or cover not fully seated | Remove cover, wipe excess grease, reseat and re-tighten evenly |
| Intermittent 4WD dropout | Drive shaft not fully seated after reassembly | Check front and rear drive shaft cup engagement — push firm until click |
If you encounter issues not covered here, our How to Upgrade Your MN82 RC Crawler: Step-by-Step Modification Tips for Beginners covers additional scenarios and advanced drivetrain diagnostics.
Next Level Upgrades
With metal gears installed, your MN82 is significantly more durable. Here is what experienced crawlers tackle next:
- Upgrade the shock absorbers — the Lumerk MN82 already includes a bonus 4-piece metal shock absorber set in the box, so you are already ahead of most stock setups. If you are running the stock plastic shocks from an earlier purchase, swap in the metal set now.
- Install a brushless motor conversion — a brushless 1410 or 1412 motor dramatically increases torque on the 46-degree climb capability and extends run time efficiency.
- Upgrade servo to a 25g metal gear servo — the stock 17g waterproof servo handles most terrain well, but a higher torque unit improves steering precision on tight rock sections.
- Add a locking front differential — for serious trail crawling, a locked front diff improves traction consistency on uneven surfaces.
- Run all three batteries back to back — the MN82 ships with three 7.4V batteries, giving you extended session time without interruption while the other two charge. Most competitor trucks include only one battery.
For a broader look at what the MN82 can do against the competition, read our detailed MN82 vs WPL C54 LC80: Which Budget RC Crawler Actually Wins? breakdown.
MN82 Specifications at a Glance
| Specification | MN82 Detail | Relevance to This Upgrade |
|---|---|---|
| Scale | 1/12 | Compact gear housings — precision tools required |
| Drive System | 4WD (Four-Wheel Drive) | Three gear upgrade locations: front diff, rear diff, central gearbox |
| Motor | 280 Brushed Motor | Metal spur gear withstands brushed motor torque spikes better than plastic |
| Max Climb Angle | 46 degrees | Metal gears maintain mesh under high-load climbing stress |
| Shock Absorbers Included | Bonus 4-piece metal set | Pairs with metal gear upgrade for full durability overhaul |
| Batteries Included | 3 × 7.4V rechargeable | Extended run time for testing post-upgrade without waiting to recharge |
| Servo | 17g Waterproof Servo | No changes required during this upgrade — servo operates independently |
| Terrain Capability | Sand, gravel, mud, grass, rocky trails | Metal gears extend service life across all terrain types |
MN82 vs WPL C54 LC80: Why the Gear Upgrade Matters More on Some Trucks
When comparing the MN82 to the WPL C54 LC80, the gear durability conversation is relevant to both. The WPL C54 LC80 is a well-regarded 1/16 scale crawler with a ladder frame chassis and solid axle design, popular among Australian hobbyists for its low price point. However, the WPL C54 LC80 ships with plastic differentials as standard and typically includes only one battery, meaning your crawling sessions are shorter and your drivetrain is working harder per run. The MN82 operates at 1/12 scale, giving it a larger gear profile that is more tolerant of metal gear fitment tolerances — an important consideration when sourcing aftermarket parts. The MN82 also arrives with a bonus 4-piece metal shock absorber set and three batteries out of the box, so you are starting the upgrade journey from a higher base specification. Both trucks benefit from metal gear upgrades, but the MN82's larger scale and more accessible gear housing layout make this specific upgrade easier to execute for beginners.
Also see our comprehensive How to Get the Most Out of Your MN82 LC79 Scale Crawler Right Out of the Box guide for setup tips that complement this metal gears upgrade.
Frequently Asked Questions
Will metal gears improve my MN82's climbing performance on steep trails?
Yes — significantly. Stock plastic gears can strip or flex under the high-torque loads experienced when the MN82 climbs its rated 46-degree maximum slope. Metal gears maintain mesh geometry under stress, which translates to more consistent power delivery to all four wheels. You will notice improved traction consistency on rocky and loose terrain where throttle input is most erratic and gear load spikes are most frequent.
How often should I re-grease the metal gears after installation?
For regular recreational use on Australian terrain — sand, gravel, bush trails — plan to inspect and re-grease the differential gears every 8–10 hours of run time. If you are running through water or mud frequently, check after every 4–5 sessions. The central gearbox typically requires less frequent attention than the axle differentials because it is less exposed to debris ingestion. A thin, consistent coat of RC gear grease is all that is needed — do not over-pack.
Does Lumerk offer support if I have issues with my MN82 after the upgrade?
Absolutely. Lumerk is an Australian seller with local customer support, fast AU shipping, and a 30-day return policy. If your MN82 develops a fault unrelated to the modification — such as an electronics issue or a manufacturing defect — the support team can assist. It is worth noting that the MN82 is Ready to Run straight out of the box, meaning the factory setup is well-dialled before any upgrades. For post-upgrade technical questions, Lumerk's support team is reachable directly through the MN82 RC Rock Crawler product page.
🚙 Shop RC Crawlers at Lumerk AU
Conclusion
Following this MN82 metal gears upgrade guide, you have now replaced the stock plastic differentials and central gearbox gears with a full metal set, re-greased all contact surfaces, and verified correct operation through both manual and powered testing. Your MN82 is now equipped to handle the demanding terrain it was designed for — sand, gravel, mud, grass, and rocky Australian trails — with significantly improved drivetrain longevity. Combined with the bonus metal shock absorber set and three batteries already included in the Lumerk MN82 package, this upgrade positions your crawler well ahead of comparably priced competitors. Ready to take the next step? Pick up your MN82 RC Rock Crawler from Lumerk with fast Australian shipping and local support. For RC crawler community resources, visit RCCrawler.com.