Royal Enfield 573907/A Rocker Cover Washer Seal – Pack of 2 | Classic/Bullet/Thunderbird UCE, GT 535

Royal Enfield 573907/A Washer Seal – Rocker Cover

Royal Enfield 573907/A is a genuine rocker-cover sealing washer used in the cylinder-head / rocker-cover assembly of selected UCE-era Royal Enfield motorcycles. Royal Enfield fiche-style sources identify the part as “WASHER SEAL ROCKER COVER.”

This is a small but important sealing component used under the rocker-cover mounting hardware. A hardened, flattened, damaged or missing washer seal can contribute to oil seepage around the rocker-cover mounting area, so the correct washer should be renewed whenever required during top-end service or rocker-cover removal.

Product Details

Confirmed / Supported Compatibility

Important Model-Year / Old-Type Note

Royal Enfield parts-catalogue data identifies 573907/A as the newer washer-seal type used from approximately March 2012 onward in the relevant UCE rocker-cover application. The older part shown for earlier assemblies is 571118/A.

If your motorcycle is an early UCE model, has had a cylinder-head / rocker-cover assembly changed, or the service history is unknown, compare the existing washer and confirm the part number before ordering.

573907/A vs 573906/A – What Is the Difference?

Both numbers appear next to each other in Royal Enfield cylinder-head / rocker-cover parts data and both are called Washer Seal Rocker Cover, but they are not interchangeable just because the description is the same.

For a complete rocker-cover service, check the parts diagram and the actual washers removed from the motorcycle rather than ordering multiple pieces of one number blindly.

When Is This Washer Seal Usually Replaced?

• Rocker cover removed during valve / top-end service
• Oil seepage visible around rocker-cover mounting points
• Old washer has become hard, flattened or cracked
• Washer is missing after previous engine work
• Rocker-cover mounting hardware has been removed repeatedly
• Engine top-end is being correctly reassembled after repair

Why This Small Part Matters

The rocker cover must be clamped correctly while maintaining its sealing arrangement. A sealing washer helps the mounting point seal correctly around the rocker-cover hardware. Reusing a visibly damaged or hardened washer can compromise that sealing interface.

Do not attempt to cure an oil leak only by overtightening the rocker-cover bolts. Correct fastener torque, gasket condition, mating surfaces and washer seals should all be inspected.

What You Will Receive

1 × Retail Pack of Genuine Royal Enfield 573907/A Washer Seal – Rocker Cover

• Pack contains: 2 washer seals

Important: Royal Enfield parts-catalogue data can show 3 × 573907/A used in the applicable rocker-cover assembly, while the genuine retail pack is supplied as 2 pieces per box/pack. Therefore, if a repair genuinely requires all 3 small washer seals, one pack will not be enough; confirm the required quantity with the technician before ordering.

Installation Note

Installation should ideally be performed during proper rocker-cover / cylinder-head service by a technician familiar with Royal Enfield UCE engines.

• Work on a cool engine.
• Confirm the correct washer position before dismantling.
• Inspect the rocker-cover gasket and mating surfaces.
• Replace visibly hardened, cracked or flattened washer seals.
• Do not substitute 573906/A and 573907/A without confirming the diagram / removed part.
• Tighten rocker-cover fasteners only to the correct Royal Enfield service specification.
• After reassembly, inspect for oil seepage after the engine has been run and cooled.

Before You Buy

• Confirm the exact part number 573907/A.
• Confirm your motorcycle is a supported UCE-era application.
• Check whether your engine uses the newer post-2012 washer arrangement.
• Remember that one retail pack contains 2 pieces; check how many washers your repair actually requires.
• Do not order this part for a newer J-Series, 650 Twin, Himalayan 450 or other unrelated engine platform without separate fitment confirmation.

Buyer-Focused FAQs

What is Royal Enfield 573907/A?
It is a genuine Royal Enfield washer seal for the rocker cover.

Is 573907 the same as 573907/A?
The complete Royal Enfield part number found in current parts references is 573907/A. Buyers and workshops may search the base number as 573907.

Does 573907/A fit Classic 350?
It is supported for the older Classic 350 UCE application. It should not be assumed to fit the newer J-Series Classic 350.

Does it fit Classic 500?
Yes. Royal Enfield fiche-style sources list 573907/A in multiple Classic 500 cylinder-head applications.

Does it fit Bullet 350 UCE?
Dealer application data supports Bullet 350 UCE kick-start and electric-start applications.

Does it fit Thunderbird 350 / 500?
Yes. Royal Enfield parts-catalogue / dealer data supports Thunderbird UCE applications, and catalogue data shows 573907/A in the rocker-cover assembly.

Does it fit Continental GT 535?
Yes. Royal Enfield fiche-style sources explicitly list Continental GT 535 Euro 3 and Euro 4 applications.

Does it fit new Classic 350 Reborn / J-Series?
No fitment is claimed. The evidence for 573907/A is for the older UCE-era rocker-cover design.

How many pieces are included in this listing?
2 pieces. 573907/A is supplied as a retail pack of two washer seals.

How many 573907/A washers can the rocker-cover assembly use?
Royal Enfield parts-catalogue data shows three 573907/A washer seals in the applicable rocker-cover assembly. Because the retail pack contains 2 pieces, confirm the total quantity required for your exact repair before ordering.

Is 573907/A the same as 573906/A?
No. Both are described as rocker-cover washer seals but they are separate Royal Enfield part numbers used in different positions.

What was the older washer number?
Parts-catalogue data identifies 571118/A as the older washer-seal reference before the newer 573907/A arrangement.

Can a bad rocker-cover washer cause an oil leak?
A damaged or hardened sealing washer can contribute to seepage around its mounting position, although rocker-cover leaks can also involve the gasket, cover, fasteners, mating surfaces or incorrect installation.