What The S20002 Does
A trailer shock damps the spring and axle motion that the suspension itself cannot control. On air-ride and spring trailers alike, the shock is what keeps the axle from continuing to oscillate after a bump. When it quits, the tire loses contact with the road for fractions of a second at a time, and that shows up as cupping across the tread.
The S20002 is built as a direct replacement unit for heavy-duty trailer suspension positions. It is supplied by World Truck Parts and is sold as an aftermarket part, not as a factory-branded item. Mounting style, extended length, and collapsed length are what determine whether it drops into your hanger, so those are the dimensions to check against the unit coming off.
Trailer shocks work in pairs across an axle and usually in sets across the group. Replacing one side only leaves you with mismatched damping, and the new unit takes the load the tired one used to share. Most shops replace by axle at minimum.
Why These Numbers Cross
S20002 and F02113S235 describe the same physical shock absorber. The second number is an OE or cross-reference identifier carried by a different supplier for the same envelope: same mounting configuration at both ends, same stroke, same damping duty for the application. It is listed here for identification only and does not imply any affiliation with or endorsement by the manufacturer that assigned it.
Cross-reference lists exist because the same shock gets a different number every time it enters a new parts catalog. Trailer builders, suspension makers, and aftermarket suppliers each assign their own. The part in the box does not change. That is why searching F02113S235 should bring you to S20002.
Treat the cross as a starting point, not a fitment guarantee. Confirm against the number stamped or tagged on the shock you are removing, or verify by trailer VIN and suspension model before you order. A trailer that has been re-axled or had its suspension swapped will not match its build sheet.
Checking Before You Order
Pull the old shock and measure it. Extended length pin-to-pin or eye-to-eye, collapsed length, and the mounting type at each end. Note whether you have eye ends with rubber bushings, a stud-style pin mount, or a mix of the two. Getting the end types backward is the most common reason a shock will not go back in.
Look for the failure evidence while you are under there. Oil film running down the shock body, a rusted or split bushing, a bent rod, or a shock that offers no resistance when you compress it by hand. Also check the hanger and bracket for elongated holes, because a worn bracket will kill a new shock fast.
S20002 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to S20002. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| OE/Cross-Ref | F02113S235 |
Frequently asked questions
Is S20002 the same shock as F02113S235?
They cross to the same trailer shock absorber. F02113S235 is listed as a cross-reference number for identification purposes only. Before ordering, verify against the number on the unit you are pulling off or check by trailer VIN, since suspension swaps and re-axled trailers often no longer match their original build.
How do I know my trailer shocks are worn out?
Look for oil streaking down the shock body, which means the seal has let go. Cupped or scalloped trailer tire wear is another strong indicator, along with excessive axle hop over rough pavement. A shock you can stroke by hand with little resistance is finished, even if it is not leaking yet.
Do I have to replace trailer shocks in pairs?
Replace at least by axle, both sides. A new shock paired with a worn one gives you uneven damping across the axle and puts extra work on the new unit. Many fleets replace the full set across the axle group during a suspension service so all units wear at the same rate.
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Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
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