Worn struts on your 2018 Toyota RAV4 at 100,000 miles is within the normal lifespan for these suspension components. Struts are wear items that typically need replacement between 50,000 and 100,000 miles depending on driving conditions and road quality.
What Struts Do
Struts combine the shock absorber and structural support for the suspension into one unit. They control spring oscillation, support vehicle weight, and maintain tire contact with the road. As the internal seals and valving wear, damping capability decreases.
Signs of Worn Struts
Excessive bouncing after hitting bumps - the vehicle continues moving up and down. Nose dive during braking. Body roll during turns. Uneven tire wear from poor wheel control. Oil visible leaking from the strut body. Clunking or knocking over bumps.
The Bounce Test
Push down firmly on each corner of the vehicle and release. A good strut should bring the vehicle back to rest within 1-2 bounces. If it bounces multiple times or feels loose, the struts are worn. This simple test gives a general indication of strut condition.
Replacement Considerations
Replace struts in pairs (both fronts or both rears) for balanced handling. Quick-strut assemblies include the strut, spring, and mount pre-assembled - easier installation and often better value. Quality aftermarket struts (KYB, Monroe, Bilstein) work well. Expect $600-900 for a pair installed.