Collection: Spring Compressors

How to choose a spring compressor

A spring compressor squeezes a coil spring so you can take the load off a strut's top nut, pull the strut apart and swap the spring, damper or mount. You need one any time you reuse a strut body or install new springs on a factory-style strut, which covers most lowering spring installs on cars and many front strut jobs on trucks.

Three things decide which tool fits your job:

• Spring type. MacPherson strut springs sit around the damper and are compressed from the outside. Springs that sit between a control arm and the frame (common on older GM cars and trucks) are often compressed from the inside.
• Spring size. Check the coil outside diameter and wire thickness against the tool's limits. For example, the Performance Tool W80556 is listed for coils up to 6 inches in diameter with wire up to 5/8 inch.
• How often you will use it. A pair of screw-type compressors is fine for one or two jobs. If you do struts regularly, a hydraulic or frame-style unit is faster and holds the spring more securely.

Spring compressor types compared

Here is what we carry right now, grouped by type. Prices are current catalog prices.

Screw-type (external) compressors

Two threaded rods with hooks grab opposite sides of the spring, and you tighten them in turns. They are cheap and compact, and they work on most car strut springs. The downside is that they rely on you keeping the hooks even and fully seated.

Internal compressors

An internal compressor goes through the middle of the spring and clamps from the inside. It suits springs that sit in a pocket where external hooks cannot reach, such as the front coils on many older body-on-frame cars.

Hydraulic and frame-style compressors

These hold the spring in a frame or cage and use a jack or a forcing screw to push it down. The hydraulic unit we stock uses a 4.5 ton jack with 1 ton of rated compression force and spring clasps that open from 5.5 to 6.7 inches. Frame tools take up more space but keep the spring captured, which is why shops prefer them.

Do you need a spring compressor at all?

Not always. If you buy a complete loaded strut assembly, the spring, mount and damper come assembled, and KYB notes that a compressor is not required for that install. Coilovers also usually go in as complete units. You only need a compressor when you are moving a spring onto or off a bare strut. If you are not sure which kind of front end your car has, our shocks vs struts guide explains how to tell.

Safety and install notes

• A compressed coil spring stores a lot of energy. KYB warns that a spring that releases unexpectedly can cause severe injury or death. Wear safety glasses and gloves.
• Inspect the tool before every use. OTC's strut compressor instructions say not to use a tool that is in poor condition.
• Compress only until the spring is loose in its seats. OTC warns that over-compression can cause tool failure and injury.
• Do not remove the strut's top nut until the spring is loose in its mounts.
• With screw-type tools, tighten both sides a little at a time so the spring stays square, and make sure every hook is fully seated on a coil.
• Use the tool on the spring types its instructions list. A tool made for strut springs is not a substitute for an internal compressor, and the reverse.

What else you'll need

A strut job is a good time to replace worn strut mounts and bump stops. If you are changing ride height, pick up your new coil springs or lowering springs at the same time, and plan an alignment once the car is back on the ground. For trucks, spring spacers are another way to change ride height that still requires taking the strut apart.

Costs

Our spring compressors run $84.99 to $424.99. Screw-type strut compressors start under $90, internal and multi-adapter sets sit in the $110 to $150 range, and hydraulic and heavy-duty units cost $209 and up. If you will only ever do one set of struts, compare the tool cost against a shop's charge to swap springs on your struts. Our cost to lower a car guide shows what installs typically add up to.

Popular picks

• Performance Tool Strut Spring Compressors W80556, $84.99: the budget choice for car struts with coils up to 6 inches.
• Performance Tool Professional Strut Spring Compressors W89322, $85.99: forged steel and a carry case for repeat use.
• SPC Performance Internal Coil Spring Compressors 40250, $113.99: for springs that sit in a control arm pocket.
• Hydraulic Strut Spring Compressor, $209.02: a frame-style unit for people who do struts often.
• SPC Performance Universal Spring Compressors 40260, $262.99: a universal option for varied vehicles.

Related guides

• Coilovers vs lowering springs
• How to lower a truck
• Spring rate explained

Sources

• KYB tool and safety guides
• OTC StrutTamer bridge instructions