DIY 3 Step Suspension Check
Identify whether your suspension is operating inside its intended load behavior or forcing the shocks to do the spring’s job.
The goal here is not performance testing. The goal is recognizing behavior patterns.
If you recognize the behavior you can fix the cause instead of replacing random parts. No mechanical experience required.
Step 1: The Corner Push Test for Van Spring Rate
What you are checking: whether the spring is carrying weight or the shock is.
Stand at the rear corner of the vehicle.
- Place both hands on the bumper or body corner
- Push down firmly using your body weight
- Release quickly
What normal feels like The van compresses slightly and returns to height in one smooth motion.
What outside load behavior feels like The van feels very stiff to push OR rebounds more than once.
What it means A suspension should use springs to hold weight and shocks to control motion. If it feels stiff or bouncy, the damper is managing weight instead of motion.
Owners often describe this as:
- harsh ride
- choppy expansion joints
- feels firm but still unstable
Step 2: The Washboard Memory Test
What you are checking: heat buildup and shock fade
Think about driving on small repeated bumps such as:
• gravel roads
• cracked city pavement
• expansion joints on highways
Normal behavior The van settles into the road and becomes predictable.
Outside load behavior The ride becomes progressively harsher the longer you drive.
What it means When dampers carry load they build heat. Heat reduces damping consistency, which causes increasing harshness over time.
Owners often ask us:
- “why does my van ride worse after 20 minutes?”
- “my sprinter rides fine at first then harsh”
Step 3: The Highway Correction Test
What you are checking: geometry stability under side load
Drive at highway speed in wind or when being passed by trucks.
Normal behavior One correction then the van stabilizes.
Outside load behavior Constant small steering corrections required to hold the lane.
What it means This usually indicates the suspension mounting geometry is deflecting under load rather than holding alignment.
Owners describe this as:
- wandering steering
- tiring to drive
- never tracks straight
How to Interpret Your Results
- If none of these feel familiar Your suspension is operating within normal behavior range.
- If one feels familiar You are approaching the edge of the system’s intended load behavior.
- If two or more feel familiar Your suspension is compensating for weight instead of supporting it.
That does not mean parts are broken. It means the system architecture may be mismatched to the vehicle’s load.
