Sierra GSS62640 Stainless Marine Gas Spring 40 lb

A gas spring is one of those parts nobody notices until it quits. Then the hatch drops on your hand, or the anchor locker lid won't stay up while you're feeding out rode, and it's suddenly the most important part on the boat. The Sierra Marine GSS62640 is a single stainless steel gas spring rated for 40 pounds of lift. Closed, it measures 7 inches. Fully extended, it's 10 inches. That's roughly 3 inches of travel doing the quiet work of holding a lid open so you don't have to hold it yourself.

We see these go into all kinds of spots. Deck hatches, anchor and rope lockers, under-seat storage, livewell lids, engine compartment covers, and console access doors. Anywhere you've got a lid that needs to stay up on its own while your hands are busy with something else. The 7 to 10 inch closed-to-extended range suits small and mid-size hatches well. On a compact anchor locker it's just about perfect. One thing to watch: the bracket offset on your hinge can eat into how far the lid actually swings, so the 10 inch extended figure isn't always the same as how far your lid opens. Measure your opening and your mounting points before you order.

The 40 pound rating is the number to pay real attention to. Weigh or estimate your hatch before you buy. A light acrylic or thin fiberglass lid is happy on a single 40 pound spring. A big, heavy fiberglass lid usually isn't, and asking one strut to do a two-strut job is how you end up with a lid that slowly creeps shut on a breezy afternoon. For heavier or curved lids, run a spring on each side so the lift stays even and the lid tracks straight. When you're on the fence between one and two, go with the pair. It's cheap insurance against a lid coming down when you don't want it to.

Here's the quick way to spec it. Measure the lid's weight, then the distance from your hinge to a solid mounting point on both the lid and the frame. You want the spring compressed when the lid is closed and near full extension when it's open, without slamming into its internal stop. If your numbers line up with 7 inches closed and 10 open, and your lid is at or under 40 pounds, this is your part. If the lid is heavier, step up to a higher-rated spring or add a second one.

Sierra builds this one from stainless steel for a reason. A plated-steel strut off the shelf at the auto parts store won't survive a season in salt air. The stainless body shrugs off spray and humidity and keeps working season after season. Give the end fittings an occasional wipe and a shot of corrosion block, since fittings and pivot hardware are always the first thing salt tries to chew on. A minute of maintenance a couple times a year goes a long way.

It's worth knowing that gas springs are wear parts. They all lose a little charge over time, and one that lives out on an exposed deck hatch in full sun works harder than one tucked inside a console or a cabin. If yours starts feeling weak or won't hold the lid all the way up anymore, that's the gas slowly bleeding down, not a defect, and it's simply time for a fresh one. A lot of boaters just replace their exposed struts on a regular schedule and never think about a dropped hatch again.

Sierra has supplied replacement parts to boat builders and engine makers for decades, and this spring is built to meet or exceed the original part it replaces. It mounts with standard end fittings. If your setup uses ball-stud mounts, use the locking clips so normal running vibration doesn't work an end loose over time. Match the length, respect the 40 pound rating, mount it clean, and the GSS62640 does exactly what good hardware should. It disappears into the background and holds your lid open every single time you reach for it.