The order we never skip — which is why the wrong part does not reach your site.
01
Confirm
Nameplate, OEM number and working conditions — checked against your machine, confirmed in writing before you pay.
02
Verify
Photos and video of the actual part, packed and labelled, before it leaves. What you see is what ships.
03
Prevent
Send the hour-meter reading and we log the service interval — you get a message before the next one is due.
04
Dispatch
Nothing leaves Xi’an until you reply "ok". You approve, then we ship — not the other way round.
Confirm this part for my machine
Machine model and part number are what let us confirm fitment in writing. Message is optional.
Overview
Fitment Note: Confirmed by the removed spring number and the engine reference. Usually one spring per valve - tell us your engine and we confirm the quantity; normally renewed as a set with collets and retainers.
Aftermarket valve mechanism spring (valve spring) 5I-7740A — a direct replacement for the Caterpillar 5I-7740 spring. It fits the Caterpillar 3066 / S6K / C6.4 diesel engine family (also 3064 / C4.2), commonly used on CAT 311 / 311B / 311C / 312B / 320 / 320B / 320C / 320D excavators.
The valve spring holds the valve against its seat and returns it after the rocker opens it. When a spring weakens, breaks or loses free length, the valve does not close fully — typical signs are a misfire, loss of compression, a rattling valve train and, in severe cases, a dropped valve. Springs are normally renewed as a set during a cylinder-head overhaul.
Coil (compression) spring, hardened valve spring wire. Confirm the removed spring number and the engine reference before ordering; tell us the engine and we confirm the quantity (usually one spring per valve).
