What gives a Power Wheels car its power? It might seem quite simple to you if you’re familiar with electronics and machinery. However, if Power Wheels tinkering is your first foray into the wide world of wires, there is plenty to learn! 

In this guide, we’re going to dissect and explore the Power Wheels Gearbox. What’s a gearbox, you ask? It’s the connection point between the motor and the wheel. A compact box with a plastic casing that holds a few metal gears, meant to use that rotational power from the motor and transfer to wheels in motion!

Why Would You Change Out a Gearbox? 

There are two methods we are going to cover in this article: replacing and upgrading

  • Replacing: trading out the old gearbox for a new gearbox. 
  • Upgrading: opening up your gearbox to change out the individual gears. 

We all know Power Wheels are an easy favorite for your kid’s outdoor toys. All that good time rolling means that your mini car has its work cut out for it! If you decided to upgrade your Power Wheels battery to a higher voltage, you might end up with gearboxes that wear out quicker. 

Those gears can become stripped, broken, or cause melting to the casing! You might choose to replace an entire gearbox for a simple-fix project. Or you may decide to upgrade individual gears to exchange the stock plastic parts with more durable metal gears. Whichever project you’re up for, it will be much more affordable than replacing your entire Power Wheels car!

How do you know that a gearbox needs some attention?

If you start to hear grinding or clanking when your child is driving their car, chances are you need to take a look at the gearbox! Scroll down to the Common Problems section to learn more about damaged gears. 

Power Wheels Gearboxes and How They Are Set Up

You can see the complete gearbox to the right in the image above. The motor is the small metal cylinder on the bottom; inside the plastic casing lies the gears, and the white plastic cog connects to the wheel.

Let’s Review The Setup of a Power Wheels Gearbox

Refer to the image above for an inside peek of what’s inside a Power Wheels gearbox. 

Four sequentially larger gears align within the box. The First and smallest gear engages with the motor’s pinion gear, and the Fourth and largest gear engages with the wheel. 

Each of these gears rotates around a steel shaft. Grease inside the casing keeps things moving smoothly and cuts down on rising heat during use. 

The most commonly stripped gear is the First, as it is the smallest and must complete far more rotations than the other, much larger, gears.

Common Problems with Power Wheels Gearboxes

Gearboxes are susceptible to a few common problems. Identifying which problem vexes your Power Wheels will help you decide whether you need to complete a replacement or an upgrade

Problem: a gear is stripped!

Solution: got broken or sheared teeth on your gears? Look a little closer at which gear is the damaged piece.

Pinion Gear:

This gear is located on the shaft of the motor. Damage to this item likely originates from an upgrade you’ve already attempted. You may have chosen the wrong size pinion gear as a replacement. 

Second, Third, or Fourth Gear:

Damage to the three latter gears is most likely due to an incident while driving. This could be a sudden shock from rough terrain, a harsh stop, or crashing the car into something. 

You can fix the problem by replacing the damaged gear with a new piece. If there is a lot of damage within the gearbox, you might want to do a complete unit replacement. 

First Gear:

This is the most common problem when it comes to Power Wheels gearboxes. The first gear is the smallest and most likely to sustain damage or wear. Take a moment to inspect the gear – just how it is stripped will inform you what went wrong.

  • A chunk of teeth are broken: the car most likely had a sudden shock or bump, meaning your child was driving on terrain that was probably too rough!
  • Every tooth is stripped in half: the pinion gear of the motor may not have been well-aligned. Check the teeth of the pinion gear as well. You might need to replace that too. 
  • Every tooth is stripped at an angle: the motor may not have been securely attached to the gearbox. There are two screws that hold the motor to the gearbox – make sure these are snug. 

After identifying what went wrong, you know what needs to be done! You may just be upgrading that first gear to a metal version, or you might also need to replace the motor’s pinion gear. 

Problem: melted gearbox!

Solution: Do you see a melted section on the plastic gearbox itself? This is due to overheating, possibly due to a poor alignment or other damaged area on the Power Wheels. Just where that melting is located will tell you which gear is at fault. 

  • Behind the Fourth gear: the largest gear may cause overheating of the plastic casing due to reasons such as a damaged axle or frame, or from tires that have been modified. 
    • Fix: replace the fourth gear with a new piece, or replace the gearbox. 
  • Behind the First gear: the smallest gear can cause overheating of the plastic casing because of poor lubrication or a gunky gearbox. 
    • Fix: upgrade the first gear with a metal piece. 

How To Replace a Power Wheels Gearbox

When you are set to simply replace the gearbox of your Power Wheels, you must obtain a compatible replacement. This will really make the process much easier! Some deep DIYers go to such lengths as to create new bushings and bearings to accommodate non-compatible gearboxes. Keep the replacement simple by triple-checking that the new gearbox will work seamlessly with your Power Wheels model. 

Got your new gearbox? Grab a flathead screwdriver, and let’s get to replacing it!

  1. Unplug your Power Wheels battery to ensure the electrical circuit is not active. 
  2. Turn your Power Wheels car upside down to access the underside. 
  3. If there is a plastic cover in place under the car, remove it now.
  4. Remove the wheels.
  5. Remove the gearbox (it should slide right off), then detach the motor. 
  6. Remove the motor by unscrewing the two attachment screws with a flathead screwdriver. Set aside. 
  7. Set the old gearbox to the side.
  8. Install the old motor (or a new motor) into the new gearbox. 
  9. Slide the new gearbox onto the axle.
  10. Attach the motor wires.
  11. Replace the wheel.
  12. Replace the protective cover.
  13. Plug in the battery to reconnect the circuit.
  14. Test it out!

Before setting your Power Wheels back onto the ground, test the accelerator to make sure the wheel will spin. Does it spin in the correct direction? Now, let your kid take it for a test drive. Does the wheel operate under weight?

How To Upgrade a Power Wheels Gearbox

Ready for a more involved upgrade? If your gearbox is in good shape, aside from a stripped gear, you might just want to replace that individual piece. The first gear is the most prone to excessive wear and is likely the piece you want to trade out for metal. 

Make sure your replacement gear is compatible with your gearbox. 

For this project, you’ll need a flathead screwdriver, your new gear, and some grease.

  1. Unplug your Power Wheels battery to ensure the electrical circuit is not active.
  2. Turn your Power Wheels car upside down to access the underside.
  3. If there is a plastic cover in place under the car, remove it now.
  4. Remove the wheels.
  5. Remove the gearbox (it should slide right off), then detach the motor. 
  6. Remove the motor by unscrewing the two attachment screws with a flathead screwdriver. Set aside. 
  7. Open the gearbox – it will be attached by four screws. There may also be safety clips in place. 
  8. Remove the first gear.
  9. While that gearbox casing is open, you have a chance to clean it out! 
  10. Install the new gear and set the three other gears back into place if you removed them as well. 
  11. Grease it up! Slap on some new grease, addressing each of the gears.
  12. Give it a spin! All those gears interact with each other. So, before you put it all back together, try manually rotating the fourth gear to see if all the other gears rotate in response. 
  13. Replace the gearbox cover.
  14. Return the gearbox to the axle, plug in the motor, and replace the wheel. 
  15. Replace the protective cover.
  16. Plug in the battery to reconnect the circuit.
  17. Test it out!

Give your car a stationary test to ensure the wheels spin well, then let your child drive it around. If all is well, you’ve succeeded in upgrading your gearbox!

Final Comments

Replacing or upgrading a gearbox is a relatively simple task. The most important part of the job is diagnosing the problem! Identifying what went wrong will point you in the right project direction. For more modifications, check out our guides on upgrading tires and modifying your kid’s electric car to go faster.

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