What Does Bottoming Out Mean on a Car? Bump Stops and Load Limits

Bottoming out means a car’s suspension has run out of compression travel. Monroe, a suspension maker, says the jounce bumper, or bump stop, is the part that cushions that moment and limits extreme movement to protect the suspension, frame and strut parts. This guide covers what the part does, what Honda, Mazda and Toyota bulletins say about bump stops, and how the load limits in an owner’s manual and on the door-pillar label fit in.

What Bottoming Out Means

In Monroe’s words, the coil spring manages everyday impacts, while the jounce bumper engages only during excessive compression. That excessive compression is what most drivers mean by bottoming out: the suspension has used its travel, and the bump stop is what is left to take the hit.

The tape measure is in the box because the one bump stop bulletin below that gives a measurement, Toyota’s, is a gap measured in millimeters.

Monroe also names a rebound bumper at the opposite end of the stroke: it absorbs impact when the suspension extends fully and eliminates the metal-on-metal noise that can occur when a strut tops out. Bottoming out is the compression end.

What Actually Stops the Suspension? The Bump Stop

Per Monroe, the jounce bumper is positioned around the piston rod of the strut assembly. Monroe says that by absorbing harsh bottom-out forces, a quality jounce bumper helps prevent damage, reduces noise and vibration, and contributes to a smoother, more controlled ride. Monroe makes its jounce bumpers from polyurethane, which it says resists weathering and abrasion. The source is Monroe’s strut components page, which says each part is included as applicable based on the original design, so not every strut has every part.

Common Causes

No maker or government page read for this guide ranks the causes of bottoming out. These are the documented ones.

Overloaded Vehicle

The 2019 Chevrolet Malibu owner’s manual has a Vehicle Load Limits section with a warning not to load the vehicle heavier than its Gross Vehicle Weight Rating (GVWR), or either the maximum front or rear Gross Axle Weight Rating (GAWR). It says overloading can cause systems to break and change the way the vehicle handles, which could cause loss of control and a crash, and that overloading can also damage the tires and shorten the life of the vehicle. The manual does not use the words bottoming out.

That letter, NHTSA interpretation letter 23087.rbm (April 25, 2002), says the GVWR informs vehicle owners how heavily the vehicle may be safely loaded. It adds that NHTSA expects ratings that reflect a good-faith evaluation of how the vehicle’s braking, tires, suspension, steering and drive train will react to its weight and intended use. The letter concerns vehicles modified for people with disabilities, so treat it as NHTSA’s explanation of the terms.

Worn Suspension Components

The Malibu manual says to visually inspect steering, suspension and chassis components for damaged, loose or missing parts or signs of wear at least once a year. It gives no wear limits for shocks or springs, and neither does any other source read here, so this guide does not either.

Lowered Suspension: Why Modified Cars Bottom Out More Often

No source read compares lowered and stock cars. What the Malibu manual does say: damage to suspension components caused by modifying vehicle height outside of factory settings is not covered by the vehicle warranty. It also lists vehicle ground clearance among the things a wrong wheel can affect, along with bearing life, brake cooling, speedometer calibration, headlamp aim and bumper height.

Rough Road Conditions

The Malibu manual’s tire section says to replace any tires that have been damaged by impacts with potholes, curbs and the like, and that overinflated tires are more likely to be cut, punctured or broken by a sudden impact such as hitting a pothole. For noises after a pothole, see our guide to noises after hitting a pothole, and for what a speed bump does, see does going over speed bumps hurt your car.

Risks Of Bottoming Out

What Happens When a Car Bottoms Out

The source read for this question is Monroe, which says the jounce bumper exists to limit extreme movement and protect the suspension, frame and internal strut components. No source read gives a list of parts damaged in a given event, a repair price, or a safe number of hits.

When the Bump Stop Itself Is the Problem

Three makers have published technician bulletins on NHTSA’s site where the bump stop, not the road, is the concern. They are summarized below. Honda and Mazda state that their bulletins are for skilled technicians and that the procedures should not be attempted by do-it-yourselfers.

Maker bulletin	Vehicles	What the bulletin describes	What the maker says to do
Honda 14-077, version 4 (Jan 26, 2026)	2006-14 Ridgeline	A pop or clunk from the rear suspension in cold weather over bumps; the rear bump stops have loosened and are moving in the top mounting cap for the rear dampers	Apply a small amount of adhesive to the upper surface of the bump stop (flat rate 2.3 hours)
Mazda 02-006/19 (Dec 20, 2019)	2014-2018 Mazda3 (Mexico built)	A knocking noise from the rear over a road bump; the bump stop (bound stopper) of the rear shock absorber is coming out of the mounting rubber	Rebuild the affected rear shock absorber using a new bump stop, mounting rubber and nut
Toyota T-SB-0070-22 Rev1 (Aug 16, 2022)	2022-2023 Tundra and Tundra Hybrid, 2023 Sequoia Hybrid with air suspension	A rough-ride feel over bumps or dips	Check the gap between each rear bump stop and the top of the rear axle housing; adjust the height control sensors only if the gap is under 35 mm, with a target of 35-45 mm (1.0 hour)

Mazda’s bulletin says the bump stop can come out of its mounting rubber when the bump stop shrinks in cold weather, when it expands in cold weather after absorbing water, or when the shock moves down after freezing between the shock and the dust cover.

Read these as examples that the part can matter on its own, not as a list of cars that bottom out. Honda and Mazda each say owners should not assume the bulletin applies to their vehicle and should contact an authorized dealer to find out.

How To Spot Bottoming Out

No source read gives a checklist of bottoming-out signs. What the bulletins above do give is how makers describe bump stop concerns:

• Honda 14-077: a pop or clunk from the rear suspension in cold weather going over bumps.
• Mazda 02-006/19: a knocking noise from the rear of the vehicle when driving over a road bump.
• Toyota T-SB-0070-22: a rough-ride feel over uneven road conditions such as bumps or dips, on air suspension trucks whose bump stop gap measures under 35 mm.

Those are symptoms for named models and causes; a noise on your car could have another. For squeaks specifically, see why is my car squeaking when I go over bumps.

Prevention Tips

Avoid Overloading

Overloading is the one cause with a documented limit, and the limit is printed on your car. Here is what the sources say about finding it:

Item	What the source says	Source
Tire and Loading Information label	On the Malibu it is attached to the center pillar (B-pillar); it shows the number of seating positions, the maximum vehicle capacity weight, the original tire size and the recommended cold tire inflation pressures	2019 Chevrolet Malibu manual
Certification label	May show the GVWR, which includes the weight of the vehicle, all occupants, fuel and cargo, and the GAWR for the front and rear axle	2019 Chevrolet Malibu manual
Payload on a Ford	Appears on the Tire and Loading label on the B-pillar or the edge of the driver’s door; look for the line that says the combined weight of occupants and cargo should never exceed a stated number	Ford support page, What is the payload capacity
Added equipment	Subtract the equipment’s weight from the label payload to get the new payload	Ford support page

The Malibu manual lists steps for the cargo allowance: find the line on the placard, add up the weight of the driver and passengers, subtract that from the placard number, and keep luggage and cargo within the result. Its worked example: with a 1,400 lb figure and five 150 lb passengers, 1,400 minus 750 leaves 650 lb. A second example, a 1,000 lb capacity weight with five 200 lb passengers, leaves 0 lb for cargo. Those are the manual’s examples, not figures for your car.

Ford adds that trailer tongue weight or king pin weight also counts as part of the payload when towing. The Malibu manual’s cargo warning is about injury, not bottoming out: things inside the vehicle can strike people in a sudden stop, turn or crash, so it says to put them in the cargo area, as far forward as possible, and spread the weight evenly.

Regular Suspension Maintenance

Beyond the yearly visual inspection in the Malibu manual, your own owner’s manual is the schedule for your car.

Related Suspension Guides

• How to repair a car that bottoms out
• What is a car suspension and why does it matter
• What do struts do on a car
• Best car shock absorbers
• Pothole damage

Frequently Asked Questions

What Does Bottoming Out A Car Mean?

Bottoming out means the suspension has reached the end of its compression travel. Monroe describes the jounce bumper, also called a bump stop, as the part that acts as a protective cushion when the suspension reaches the end of its compression travel and limits extreme movement to protect the suspension, frame and internal strut components.

What Is a Bump Stop, and Does Every Car Have One?

Monroe describes the jounce bumper as positioned around the strut’s piston rod and says it is included in its strut assemblies as applicable based on the original design. Honda, Mazda and Toyota each have a bulletin that names the bump stops on specific models (2006-14 Honda Ridgeline, 2014-2018 Mazda3, 2022-2023 Toyota Tundra), but the sources read do not say whether every car has one.

What Causes A Car To Bottom Out?

The 2019 Chevrolet Malibu manual names loading beyond the vehicle’s weight ratings as something that can change the way the vehicle handles and damage the tires. Changes to ride height outside factory settings are another documented issue: the same manual says suspension damage caused by that is not covered by the warranty. The sources read give no ranked list of causes.

How Can I Prevent My Car From Bottoming Out?

The documented step is staying inside the load limits. Ford says the maximum payload appears on the Tire and Loading label, and the Malibu manual says the combined weight of the driver, passengers and cargo should never exceed the vehicle’s capacity weight. Your owner’s manual and door-pillar label give the numbers for your car.

What Are The Symptoms Of A Car Bottoming Out?

No source read lists bottoming-out symptoms as such. Honda bulletin 14-077 and Mazda bulletin 02-006/19 describe a pop, clunk or knocking noise from the rear over bumps on named models, traced to the bump stop. A dealer or qualified technician has to diagnose a noise on your car.

Do Lowered Cars Bottom Out More Than Stock Cars?

The sources read do not compare lowered and stock cars. The 2019 Chevrolet Malibu manual says damage to suspension components caused by modifying vehicle height outside of factory settings is not covered by the vehicle warranty, and that the wrong wheels can affect vehicle ground clearance.

What This Guide Does Not Cover

• Repair prices; ask a shop or dealer for an estimate.
• Scrapes on driveways and dips and what they can damage underneath.
• Step-by-step repair or diagnosis; use your owner’s manual and a dealer or qualified technician.

Conclusion

Bottoming out is the suspension reaching the end of its compression travel, the point where Monroe says the jounce bumper engages to limit extreme movement. The documented controls are the vehicle’s own load limits, a yearly look at suspension parts, and a dealer visit when a noise matches a bulletin like Honda 14-077 or Mazda 02-006/19. The manual and label for your car are the final word on weight.