2021 Toyota 4Runner Problems: 3 Issues Every Owner Should Know

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Community Reported

876 owners

On the 2010-2023 Toyota 4Runner, the KDSS hydraulic suspension system can develop leaks at the hydraulic lines and accumulators, especially in areas with road salt. The system helps reduce body roll on-road while allowing articulation off-road. Corrosion of the KDSS lines is common in northern states.

Common Symptoms

Hydraulic fluid leaking under front/rear
KDSS warning light on dash
Poor handling or excessive body roll
Clicking from front suspension
Visible corrosion on KDSS lines

How to Fix

Inspect KDSS lines annually for corrosion. Apply rust protectant to exposed lines. For leaking accumulators: Replace with new units ($300-600 each). Hydraulic line leaks require line replacement. Some owners delete KDSS entirely and install conventional sway bars ($500-1,500). Full KDSS repair at dealer: $1,500-4,000.

What Owners Are Using

Parts and tips from 876+ owners who fixed this issue

TipDIY repairs can save significantly - dealer charges $300-600 but DIY costs are typically 50-70% less
TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
TipSearch Toyota 4Runner forums and owner groups for real-world experiences and DIY guides
TipGet multiple quotes from independent mechanics - dealer prices can be 2-3x higher for the same repair
UpgradeComplete strut and shock absorber set for full suspension refresh (KYB Excel-G Strut/Shock Set)
View on Amazon
UpgradeFour-wheel alignment kit with cam bolts for proper tire wear correction (Moog Alignment Cam Bolt Kit)
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Typical repair cost:$300 - $4,000

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876+ owners have reported this issue

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Community Reported

High Confidence876 reportsLast reported by owners Feb 2024Reviewed Feb 2026

Community Reported

678 owners

On the 2010-2023 Toyota 4Runner, a clunk or pop may be heard from the steering column area when turning the wheel, especially at low speeds or when going from left to right. The issue is typically the intermediate steering shaft or worn rack bushings. Common on vehicles driven off-road.

Common Symptoms

Clunk when turning wheel at low speed
Pop when turning from stop
Noise from steering column area
Play in steering wheel

How to Fix

For intermediate shaft noise: Lubricate the shaft splines with white lithium grease (temporary fix) or replace shaft ($200-400). For steering rack clunk: Tighten rack mounting bolts or replace rack bushings. Full rack replacement if worn ($800-1,500). Have alignment checked after any steering work.

What Owners Are Using

Parts and tips from 678+ owners who fixed this issue

TipDIY repairs can save significantly - dealer charges $200-400 but DIY costs are typically 50-70% less
TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
TipSearch Toyota 4Runner forums and owner groups for real-world experiences and DIY guides
TipGet multiple quotes from independent mechanics - dealer prices can be 2-3x higher for the same repair
UpgradePolyurethane bushing kit for longer life and tighter handling than OEM rubber (Energy Suspension Bushing Kit)
View on Amazon
UpgradeSway bar end links to eliminate clunking over bumps (Moog Sway Bar Link Kit)
View on Amazon

Typical repair cost:$50 - $1,500

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678+ owners have reported this issue

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Community Reported

High Confidence678 reportsLast reported by owners Feb 2024Reviewed Feb 2026

Community Reported

432 owners

On the 2010-2022 Toyota 4Runner, the A/C compressor can fail prematurely, often sending metal debris throughout the system. When the compressor fails, the entire A/C system typically needs to be flushed and the condenser, drier, and expansion valve replaced along with the compressor to prevent repeat failure.

Common Symptoms

A/C not cooling
Clicking or grinding from compressor
A/C clutch not engaging
Metal shavings in refrigerant
Burning smell when A/C on

How to Fix

If compressor fails with debris: Replace compressor, condenser, drier/accumulator, and expansion valve. Flush all lines. Use only OEM or Denso compressor for reliability. Cost: $1,200-2,000 at shop. Preventive: Run A/C for a few minutes monthly even in winter to keep seals lubricated.

What Owners Are Using

Parts and tips from 432+ owners who fixed this issue

TipDIY repairs can save significantly - dealer charges $1,200-2,000 but DIY costs are typically 50-70% less
TipPreventive: Run A/C for a few minutes monthly even in winter to keep seals lubricated.
TipConsider OEM parts for critical components like sensors and electrical parts - aftermarket can be unreliable
TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
UpgradePrestone coolant flush kit for complete cooling system service (Prestone Coolant Flush Kit)
View on Amazon
UpgradeStant thermostat — preventive replacement during coolant service (Stant Thermostat)
View on Amazon

Typical repair cost:$1,200 - $2,500

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432+ owners have reported this issue

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Community Reported

Medium Confidence432 reportsLast reported by owners Feb 2024Reviewed Feb 2026

⚠️NHTSA Recalls8 recalls

EQUIPMENT:OTHER:LABELS

Southeast Toyota Distributors, LLC (SET) is recalling certain 2023 Toyota 4Runner vehicles. The load carrying capacity modification label states the incorrect load carrying capacity, which can result in an overloaded vehicle. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."

Campaign #23V68000012/10/2023

EXTERIOR LIGHTING:HEADLIGHTS

Southeast Toyota Distributors, LLC (SET) is recalling certain 2022 Toyota 4Runner vehicles. The driver's side high beam may be inoperable after the installation of accessory fog lights. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."

Campaign #21V96300013/12/2021

EQUIPMENT:OTHER:LABELS

Southeast Toyota Distributors, LLC (SET) is recalling certain 2020-2022 4Runner vehicles equipped with 20-inch Black Gunner Wheels. The load carrying capacity modification labels are incorrect. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."

Campaign #22V48000006/07/2022

EQUIPMENT:OTHER:LABELS

Gulf States Toyota, Inc. (GST) is recalling certain 2022 4Runner, Tacoma, Highlander, and Highlander Hybrid vehicles. The load carrying capacity modification labels may not be permanent and can fade, becoming illegible. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 110, "Tire Selection and Rims."

Campaign #22V31000006/05/2022

FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP

Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain 2018-2019 4Runner, 2019-2020 Avalon, 2019 Corolla Hatchback, 2017-2019 Highlander, 2018-2020 Camry, 2020 Corolla, 2018-2019 Land Cruiser, 2017-2020 Tacoma, 2019-2020 RAV4, 2019-2020 Sequoia, 2017-2020 Sienna, 2019-2020 Tundra, 2018-2020 Lexus ES350, 2017 Lexus GS200t, 2017-2019 Lexus GS350, 2019 Lexus GS300, 2018-2020 Lexus LC500h, 2019-2020 Lexus LS500, 2018-2019 Lexus GX460, 2017 Lexus IS200t, 2019 Lexus IS300, 2019 Lexus IS350, 2018-2020 Lexus LC500, 2018 Lexus LS500, 2019 Lexus LS500h, 2018-2019 Lexus LX570, 2017 Lexus RC200t, 2019 Lexus RC300, RC350, 2017 and 2019-2020 Lexus RX350, 2018-2020 RX350L, 2019 Lexus UX200, 2018-2019 Lexus NX300 vehicles. The low-pressure fuel pump inside the fuel tank may fail.

Campaign #20V68200004/11/2020

+ 3 more recalls. Check all on NHTSA.gov

Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

Frequently Asked Questions

What are the most common Toyota 4Runner problems?

According to Au7o's analysis of 1,986+ owner reports, the 2021-2021 Toyota 4Runner has 3 documented issues. The most frequently reported are: KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion, A/C Compressor Failure, Steering Rack Clunk / Intermediate Shaft Noise. None are rated critical, but regular maintenance is recommended.

Is the Toyota 4Runner reliable?

The 2021-2021 Toyota 4Runner has 3 known issues documented across 1,986+ owner reports. No issues are rated critical, suggesting generally good reliability. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Toyota 4Runner problems?

Repair costs for known Toyota 4Runner issues range from $50 to $4,000, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2010-2023 Toyota 4Runner KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion?

The KDSS hydraulic suspension system can develop leaks at the hydraulic lines and accumulators, especially in areas with road salt. The system helps reduce body roll on-road while allowing articulation off-road. Corrosion of the KDSS lines is common in northern states. Repairs typically run $300-$4,000. Severity: medium.

What is the 2010-2022 Toyota 4Runner A/C Compressor Failure?

The A/C compressor can fail prematurely, often sending metal debris throughout the system. When the compressor fails, the entire A/C system typically needs to be flushed and the condenser, drier, and expansion valve replaced along with the compressor to prevent repeat failure. Repairs typically run $1,200-$2,500. Severity: medium.

What is the 2010-2023 Toyota 4Runner Steering Rack Clunk / Intermediate Shaft Noise?

A clunk or pop may be heard from the steering column area when turning the wheel, especially at low speeds or when going from left to right. The issue is typically the intermediate steering shaft or worn rack bushings. Common on vehicles driven off-road. Repairs typically run $50-$1,500. Severity: low.

2021 Toyota 4Runner Problems: 3 Issues Every Owner Should Know | Au7o

2021 Toyota 4Runner Problems: 3 Issues Every Owner Should Know

All 3 Known Issues

2010-2023 Toyota 4Runner: KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion#

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

2010-2023 Toyota 4Runner: Steering Rack Clunk / Intermediate Shaft Noise#

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

2010-2022 Toyota 4Runner: A/C Compressor Failure#

Common Symptoms

How to Fix

What Owners Are Using

Research This Issue

Other Toyota Models

Frequently Asked Questions

What are the most common Toyota 4Runner problems?

Is the Toyota 4Runner reliable?

How much does it cost to fix common Toyota 4Runner problems?

What is the 2010-2023 Toyota 4Runner KDSS (Kinetic Dynamic Suspension System) Leaks/Corrosion?

What is the 2010-2022 Toyota 4Runner A/C Compressor Failure?

What is the 2010-2023 Toyota 4Runner Steering Rack Clunk / Intermediate Shaft Noise?