This little guy’s job is pretty simple, but absolutely vital. It securely fastens the connecting rod to the piston. Think of the connecting rod as the arm that links the piston moving up and down to the crankshaft that actually spins and powers the wheels. This screw is one of the things holding that arm on tight. It needs to withstand a lot of force and stress from those moving parts. It’s a core component in the engine's bottom end. Without it, you’ve got no reliable connection between the piston and the crankshaft. Basically, your engine won’t run. It’s a pretty fundamental piece—it helps convert the up and down motion of the pistons into the rotational power that gets your car moving. It's important because if this screw fails, you’re looking at major engine damage. It acts like a shield protecting everything else. If it lets go, the connecting rod can come loose, banging around inside the engine. That can knock a hole in the engine block, ruin the crankshaft, and just create a whole lot of mess. You’ll notice if one of these is going bad – usually with a really loud knocking sound coming from the engine. It's definitely one of those parts you don’t want to gamble with. You can find these, and a lot of other engine parts, over at Fixparts Online if you need one. It’s always best to replace these when you’re doing other engine work to avoid bigger issues down the road. Long-term solution: Screw (MPN A4420380071) comes with a 12-month warranty!

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• Keep your truck running its best with parts made specifically for it. That means a better fit and reliable performance. • Genuine Mercedes-Benz parts are built to last, helping you avoid costly repairs and downtime on the road. • We offer a wide range of parts, from routine maintenance items to complex engine components, all readily available. • Trust the quality and expertise of Mercedes-Benz – we stand behind every part we sell, ensuring peace of mind for you and your business. Drive with confidence – choose Mercedes-Benz Trucks parts at FixParts Online.