How to Measure and Set Sag on Your Toyota 4Runner with 5100/5160 Shocks

Quick Answer

To set sag on your Toyota 4Runner with Bilstein 5100/5160 shocks, measure the distance from the center of the wheel to the fender edge at full extension, then with the vehicle loaded to your normal driving weight. The difference is your sag. Adjust the preload on the coilovers or add load to achieve the recommended sag range, typically 20-30% of total shock travel for off-road use.

Setting sag is one of the most important steps after installing new shocks on your Toyota 4Runner. Sag, or ride-height drop, determines how much suspension travel is available for compression and extension, directly affecting ride quality, handling, and off-road capability. With the Bilstein 5100/5160 shocks, getting the sag right ensures you use the full range of the shock's monotube design.

This guide walks you through measuring sag on your 4Runner, explains why it matters, and shows you how to adjust it using the preload settings on your Bilstein shocks. Whether you're prepping for a trail run or just want a stable highway ride, these steps help you dial in the correct ride height.

Why Sag Matters on Your 4Runner

Sag is the difference between the suspension at full extension and at rest with the vehicle's weight on it. If sag is too high, the suspension sits low in its travel, reducing droop and increasing the risk of bottoming out on bumps. If sag is too low, the suspension is too stiff, and the tires may lose contact on uneven terrain.

For a Toyota 4Runner, a common target is 20-30% of total shock travel. The Bilstein 5100/5160 shocks are designed to handle a range of loads, but the correct sag ensures the shock's internal bump stop and rebound zone work as intended. Measuring sag before adjusting preload helps you avoid guesswork and keeps your suspension balanced.

• Always measure sag with the vehicle on level ground and with normal cargo or passenger load.
• Use a tape measure or a dedicated suspension sag gauge for accuracy.

Tools You'll Need

To measure and set sag, you need a tape measure or measuring stick, a jack or lift to support the vehicle, and a marker or chalk to mark reference points. You'll also need the manufacturer's recommended sag specification for your specific 4Runner model and shock setup.

For adjusting preload on the Bilstein 5100/5160, you'll need a spanner wrench or the appropriate tool for the shock's adjuster ring. If you're not comfortable adjusting preload yourself, a professional suspension shop can do it, but the process is straightforward with the right tools.

• Keep a notebook to record measurements before and after adjustments.

Step-by-Step: Measuring Sag

Start by parking your 4Runner on a flat, level surface. Make sure the tires are inflated to the recommended pressure. Measure the distance from the center of the wheel hub to the fender edge (or a fixed point on the frame) and record this as the 'static height.'

Next, lift the vehicle until the suspension is at full droop. Measure the same distance again and record it as 'full extension.' The difference between these two measurements is your current sag. Compare this to the recommended sag range for your setup.

• If you have aftermarket bump stops, measure to the bump stop contact point for a more precise reading.

Adjusting Sag on Bilstein 5100/5160

The Bilstein 5100 front struts feature a snap-ring preload adjustment that changes ride height. To increase sag (lower the ride height), move the snap ring to a lower groove. To decrease sag (raise the ride height), move it to a higher groove. The rear 5160 shocks are typically non-adjustable, so sag adjustment there is done via spring preload or by adding/removing load.

After adjusting, re-measure the sag to confirm you're within the target range. It's normal to need a couple of iterations. Always test drive after adjustment to feel the difference and check for any unusual noises.

• Make small adjustments (one groove at a time) and re-measure to avoid overshooting.

Common Mistakes and Checkpoints

One common mistake is measuring sag with an empty vehicle when you usually drive with cargo or passengers. Always measure with your typical load. Another is forgetting to reset the suspension by bouncing the vehicle before measuring, which can give a false reading.

Check that the vehicle is level and that the tires are properly inflated. If you have aftermarket upper control arms or other suspension mods, they can affect sag readings. When in doubt, consult the shock manufacturer's specifications.

• Re-check sag after a few hundred miles of driving, as springs and shocks can settle.

Step-by-Step: Setting Sag on Your 4Runner

1. Measure static height: Park on level ground, measure from wheel center to fender edge, record as static height. This is your baseline.
2. Lift to full droop: Jack up the vehicle until the suspension hangs free, measure the same distance again. Difference = current sag.
3. Compare to spec: Check your sag against the recommended range (typically 20-30% of shock travel). If out of range, proceed to adjust.
4. Adjust front preload: Use a spanner to move the snap ring on the Bilstein 5100 to raise or lower ride height. Small changes only, re-measure after each.
5. Adjust rear if possible: For 5160 shocks, adjust spring preload or load distribution to fine-tune sag. Not all rear shocks are adjustable.
6. Re-measure and test drive: After adjustments, re-measure sag and take a test drive to confirm ride quality. Repeat if needed until sag is within spec.

Product Facts

• 6112 Assembled Set includes 5100/5160 Shocks for 2010-2024 Toyota 4Runner: Thyssenkrupp Bilstein of America warrants its gas pressure shock absorbers against defects in workmanship and materials for as long as you, the original purchaser, own your car. This lifetime warranty gives you confidence when adjusting sag, knowing that the shocks are built to last and any manufacturing defects are covered.
• Bilstein 5100 Monotube Strut & Shocks Set for 2019-2024 Chevrolet Silverado 1500 4WD RWD w/0-2.5: Thyssenkrupp Bilstein of America warrants its gas pressure shock absorbers against defects in workmanship and materials for as long as you, the original purchaser, own your car. While this set is for Silverado, the same warranty and quality apply to Bilstein shocks for your 4Runner, ensuring reliable performance after sag adjustment.

Setting sag on your Toyota 4Runner with Bilstein 5100/5160 shocks is a straightforward process that pays off in ride quality and off-road performance. By measuring carefully and making small adjustments, you'll get the most from your suspension. For more tips and products, visit Shock Surplus.