How to Modify & Upgrade a Power Wheels Gearbox

Do you hear a grinding noise emanating from your Power Wheels tires? If so, you might have broken gears, which means it’s time to upgrade your gearbox.

Power Wheels ride-on cars have their perks, but one thing that might stop your kid from enjoying the vehicle to its full capacity is the stock plastic gears in the gearboxes. It should be no surprise that they don’t have the torque to last long.

One other situation where you might need to modify your gearbox motors is if you’ve just upgraded your battery or motor. Running your Power Wheels on upgraded systems and an outdated motor gearbox is sure to lead to some breakdowns down the line.

There are two ways to go about modifying your gearbox motor. You can either replace the stock plastic gearbox with a metal one or upgrade your existing motor gearbox by replacing the first gear.

But before you do any of that, here’s a crash course on Power Wheels gearboxes.

Features of a Power Wheels Gearbox

Modern Power Wheels use the 7R gearbox motors. They’re still compatible with Power Wheels models from the previous decade, so if you got your vehicle for dirt cheap at a garage sale, consider upgrading to the 7R gearbox—you might have a 10-year-old ride-on on your hands.

A motor gearbox has five internal gears you should know about:

  • The pinion gear, which is connected to the motor. It’s the first in the sequence.
  • The first gear, which is attached to the pinion gear. It’s the smallest in the sequence.
  • The second gear, which is above the first gear.
  • The third gear, which is between the second and fourth gear.
  • The fourth/final drive gear, which is opposite the first gear. It’s the largest in the sequence.

For the 7R motor gearboxes, the pinion gear is the most significant. This is because its size determines the respective gear ratios.

A car with a small pinion gear in the gearbox is slower; though it has more power and torque. These pinion gears are for riders who like intense activities (e.g., mud bogging) and are found in a car like a dune buggy.

The opposite is true for cars with bigger pinion gears in the gearbox – they have low power and better speed. Such cars do not function well on uneven terrain.

Before moving on to replace your gearbox motor, make sure that the replacement metal gearbox has the same voltage as your Power Wheels battery and motor. If you own a car with a 12V battery and a 12V motor, make sure to fit it with 12V gearbox motors.

Replacing a Power Wheels Gearbox

To proceed with this process, you’ll only need a screwdriver and a power drill. If you have both, proceed with the following steps.

1. Deconstruct Your Power Wheels

Start by locating your Power Wheels gearboxes. For most ride-on cars, they’re on the rear wheels, but as with most Power Wheels upgrades, this will depend on the model of your Power Wheels.

Put your car on a flat surface, and if you know where your motor gearboxes are located, take out the protective casing. It’s below the rear-wheel axle.

You’ll have to take out some obstructive parts of the car to access it.

Start by removing the wheels. To do this, take your trusty screwdriver and pop off the tabs securing the hubcap on the wheel.

Afterward, remove the screw on your rear axle. This will loosen up your tire, and you’ll be able to pull it right off.

Do this to the other rear wheel as well. When done, you’ll see the protective cover.

Grab your power drill and remove the screws holding it in place. When done, safely take it out, and place it to the side.

2. Remove the Gearbox

Next, you’ll need to remove the metal rod that runs across your Power Wheels i.e., the axle. It’s not attached to the wheels, so you can just take it off without any special equipment.

Now that you’ve taken out all the obstructive elements, you’ll see the gearbox in its housing. You’ll also see that it’s connected to a motor by a couple of wires.

Remove the gearbox and isolate it from the motor by removing the two screws holding the system in place. When done, move on to the main part of the process.

3. Replace the Gearbox

Your replacement gearbox should be metallic. To find out which model you should use, check out the information on the back part of the gearbox casing.

Attach the new gearbox to the stock motor by screwing in the two screws. Follow this up by returning the setup to its housing.

Do this to the other gearbox motor as well. 

It’s advisable to replace both because if one has problems, the chances are high that the other gearbox will break down, so it’s best to prevent further gear failure down the line.

4. Reassemble Your Power Wheels

Next, return your axle by inserting it through the wheel mount. When done, retrace your steps and screw in the gearbox cover with your screwdriver.

Get your tires and fit them through your balanced axle. Secure your hubcaps on each wheel and confirm that your ride-on car is back to the state it was before.

5. Test It Out

Finally, test it out with the kids. Measure its performance when driving both faster and slower.

Upgrading a Power Wheels Gearbox

If you don’t want to go through the process of buying gearbox motors, another way of reaping the benefits of a new motor gearbox is by replacing the first gear. This is also more suitable as the 7R gearboxes are more durable than those you’ll get on the aftermarket.

Despite being the smallest, the first gear is also the most vulnerable, meaning it’s more likely to break or have issues. So it makes sense that it’s the main focus of our upgrade.

Aside from your power drill and screwdriver, you’ll also need a couple of hardened-steel first gears, a dry towel, and some grease. Once acquired, go through the following steps.

1. Remove Your Wheels

On a pavement, take your screwdriver, and pop open the axle cover. You’ll see a nut here.

Unscrew the retainer nut and take it out of the axle. You’ll loosen up your wheels and you can take them off.

2. Locate the Gearbox

This process is similar to Step 1 in the previous section. You’ll need to gain access to your gearbox motors by unscrewing the protective covering.

With your tires already out, the covering will be visible.

Remove the screws holding it in place and set it aside. Take out both your gearboxes and detach them from their respective motors by unscrewing the two screws holding the unit together.

3. Replace Your First Gear

With the gearboxes isolated from the two motors, we’ll need to open them up to access the gears. Remove the screws securing the gearbox cover and take it out.

The 7R gearboxes have multiple numbers on the casing. This differentiates them from the gearboxes in the older models as they had only one number stamped on the casing to indicate the motor pinion size.

Inside the gearboxes, you’ll see the internal gears attached to a steel shaft. The first gear is the smallest, so it’s easy to pick out.

Take the gears out of their mounting holes and with your dry towel, clean out any gunk in the interior of the gearbox motors. After doing so, go ahead and install the new hardened-steel gear for much-needed torque.

Return your gear posts to the shaft and grease them up to reduce friction. Return the gearbox cover and screw it on tight.

Do this for both gearboxes. After doing so, reattach the gearboxes to their respective motors and return them to their location.

Screw in the protective covering and get your tires.

4. Reinstall Your Tires

Return the tire to the axle and screw in the retainer nut. Fix in the tire on the 

other side of the Power Wheels and reinstall your axle cap.

5. Test it Out

Finally, take your ride-on car out for a test drive.

Quick Tips on Power Wheels Gearboxes

If you are replacing your motor pinion gear for more power, make sure that the tooth count of the new pinions lines up with that of the old one. 

You’re likely to use an aftermarket pinion for your gearbox motors. If so, make sure to match it with the middle number on the casing (if your casing number is 15-16-17, for example, your aftermarket pinion gear should match that of the middle number i.e., you’ll have to get a 16t motor pinion gear).

If you want to further reduce wear and tear after a gear upgrade, consider installing a brake-reduction module in your gearbox motors.

Don’t install rear rubber traction as it can overheat motors. This will cause more gear failure and upset the system as a whole.

Make sure that your kids drive the Power Wheels in the right conditions and at the right speed, according to the terrain. Spinning the vehicle on uneven terrain or a surface with sudden drops is almost always a bad idea if you want to avoid having broken gears every two months.

Conclusion

If you’ve recently gone through a battery upgrade, it’s best to set yourself up for a potential motor gearbox upgrade too. The process is a bit longer (due to having to deconstruct your Power Wheels), but it’s not as technical.

If you’re not used to this type of work, set aside a weekend afternoon to focus on the steps outlined above. It’s better to take it slow than to rush things and make a mistake.

If you do, it could be detrimental to the child riding the toy as the gears might break. Go through the process with caution, and ensure that the gearboxes are well secured before letting kids use the toy.

Upgraded gearboxes always result in a better, more powerful ride-on for the children to enjoy.