truck undercarriage

How to Clean the Undercarriage of a Truck

Figuring out how to clean the undercarriage of a truck can be an intimidating task if you’ve never done it before. It’s the kind of thing you might not think about doing since no one can see it anyway—you might even wonder why you need to clean it at all, in fact. Cleaning your car is about more than just its appearance. It’s also key to maintaining your vehicle in the long-term, something that’s especially true of an area like the undercarriage, which picks up a lot of dirt and grime from the road.


The good news is that cleaning a truck undercarriage isn’t especially hard once you know how to go about it. We’ll break it down for you here so that you know what to do the next time your vehicles due for a cleaning.

Tip 1: Use undercarriage spray for a quick clean.

You probably already have an arsenal of cleaning supplies that you use for your car, but you might want to consider getting one more. Undercarriage spray (>>> Check on Amazon) is an affordable and easy to use product that can save you a ton of time when you’re cleaning.

When you spray undercarriage spray onto your truck, it will coat every surface, down into all the little nooks and crannies. Do this about once a week and it will prevent the build-up of oil and dust. Maybe the best part is that your truck doesn’t have to be clean before you can use it. A few sprays will not only prevent new dirt from accumulating on the undercarriage, it will help to loosen up anything that was on there already, making it easier to clean off down the line.

Tip 2: Invest in a pressure washer.

A lot of people avoid using a pressure washer on their truck exteriors because of the concern that it will damage the paint. This concern is definitely legitimate, but for the engine block or undercarriage there’s no easier way to work out chunks of salt and gravel, or get all of the dirt out of all the cracks and crevices in the mechanical part of your truck.

If you have a lifted truck, getting to the undercarriage with a pressure washer shouldn’t be too difficult. For other styles of vehicle, though, this can be a bit trickier. You can use jacks to raise the vehicle then remove the wheels, giving you easier access underneath the truck—a bit of a time consuming process but an effective way to reach the entire undercarriage.

Alternatively, if you just want to do a general wash and aren’t concerned with being able to see what you’re washing, you can make your own undercarriage attachment for your pressure washer that will let you use it under a truck without jacking it up. This will require some tools and mechanical knowledge, but once you’ve made it you’ll be able to use it for any vehicle. Most people find it’s well worth the effort to avoid having to jack up the truck every time the undercarriage needs a touch-up. (>>> You might want to try one these wash soaps)

Tip 3: Use a degreaser and brush to remove difficult grime.

Oil-based grime can be some of the most difficult to clean, and grease build-up can trap road salt and gravel—things that can damage your undercarriage over time. A degreaser like Oil Eater (>>> Check on Amazon) can dissolve this grease without being abrasive or acidic and is a handy tool for cleaning your undercarriage—a place where lots of engine oil is likely to accumulate.

If you want to do an overall clean, you can spray degreaser on the entire undercarriage, let it sit for 15-20 minutes, and then wash it away with your pressure washer. You can also use it as a spot-clean treatment. Spray especially soiled areas with degreaser, let it sit a few minutes, then use a brush to scrub the build-up off.

Unlike with pressure washing, there’s no easy hack for spraying degreaser without lifting your truck. If you don’t have a lifted truck, you’ll need to use jacks to raise it while you’re cleaning. Don’t expect a standard jack to be enough for this, either. As you’re scrubbing it will jostle your truck, and this can make it slip off of its jacks if you haven’t taken the right safety precautions.

Tip 4: Protect your undercarriage with a rubberized spray.

One of the main reasons to clean your truck undercarriage is to prevent rust. Keeping it clean will help, but your undercarriage will also be exposed to lots of moisture as you’re driving, along with other damaging compounds like road salt. A rubberized undercoating spray (>>> Check on Amazon) will protect your truck between cleanings, and make it easier to clean when the time comes.

One word of caution: moisture can’t pass through a rubberized coating—in either direction. You need to make absolutely sure that the surface of your vehicle is completely dry before applying the coating (>>> Learn about cermaic coatings here). If you don’t, drops of moisture may get trapped under it and against your vehicle. This can have the opposite effect from what you want, causing the metal to rust more quickly than it would otherwise.

Even if you don’t want to take the time to spray your entire undercarriage, you’ll probably want to protect the most important areas—namely the fuel and brake lines, which are not only some of the most important features of your truck’s undercarriage but also the parts likely to rust the fastest.

The summary: How to clean the undercarriage of your truck

As tricky as it can be to get to the undercarriage, the actual cleaning process is a lot easier than with other parts of the car. There’s no paint to worry about scratching or stripping, and it’s more about maintenance than appearance so you don’t need things to be perfect.

A pressure washer is a great tool for getting rid of stubborn, stuck-on grime, and it’s the perfect thing to use on an undercarriage. The only exception is if you have an older car that already has some rust damage (>>>Learn about rust preventions sprays). Rust weakens metal and makes it more susceptible to damage. If your vehicle is older (especially if you bought it used) you’ll probably want to lift it up and scope out the condition of the undercarriage before you commit to cleaning it with a pressure washer, just to make sure you won’t make any damage that’s there worse.

As for how often you should clean your undercarriage, that’s a matter of where you live and what kinds of roads you drive on. If you live in an area that gets snow, you’ll want to wash it more often in the winter—road salt is one of the biggest enemies of your car.

As intimidating as it sounds, cleaning your truck’s undercarriage is pretty easy once you get the hang of it. The key is to have the right tools and materials. We hope the tips here have given you the guidance you need to keep your truck in tip-top shape.