ERR3424 Rocker Cover Bolt Washer 300Tdi Defender D1 RRC - Set of 3

Spec sheet

Collected from 1 supplier page - confirm fit with the supplier before ordering.

The 300Tdi engine found across the Defender, Discovery 1, and Range Rover Classic is one of the most enduring and well-regarded diesel powerplants Land Rover ever produced, and like any engine, it depends on a complete set of properly functioning seals and gaskets to stay leak-free. The rocker cover, which sits on top of the cylinder head and encloses the valve train, is secured by three bolts, and each of those bolts passes through a combined sealing and retaining washer. Part number ERR3424 is that washer, and its job is to create an oil-tight seal between the bolt head and the rocker cover surface while also acting as a retaining element that holds the bolt captive in the cover. Over time and through repeated heat cycles, these washers harden, compress, and lose their sealing ability. The result is typically a minor but persistent oil weep from one or more of the three rocker cover bolt positions, often visible as an oily residue along the side of the engine or a faint smell of burning oil from the engine bay. Because the fix is so straightforward and the part is so inexpensive, this is one of the most cost-effective sealing jobs on the entire 300Tdi engine. Three washers are required per engine, one for each rocker cover bolt position, and best practice is to replace all three at the same time rather than addressing only the one that appears to be leaking. Replacement requires removing the rocker cover, which on the 300Tdi is a manageable job for any owner with basic mechanical aptitude. While the cover is off, it is worth inspecting the rocker cover gasket itself, as the two components share the same service interval and the gasket is often replaced at the same time. The washers simply push onto the bolts and are held in place by the bolt head, requiring no adhesives, sealants, or special tools to install correctly. This listing is priced per individual washer. If you require a full set of three to complete a rocker cover reseal, please add the appropriate quan

Suppliers (1)

• Lucky8 Off Road

  ERR3424 Rocker Cover Bolt Washer 300Tdi Defender D1 RRC - Set of 3 · Orderable · stock unverified

  Checked Nov 5, 2026
  $15.91
  View at supplier

Specifications and fitment

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Set of 3

Price history