Maxwell Windlass Service Agent Reference Manual

What Is in the Manual

The RC6, RC8, RC10, RC12, HRC-FF and Anchormax parts are covered in detail on their own owner's manual pages; this page keeps the service information that is only in the reference manual.

50mm Wormbox: Identify, Replace, Service

• Maxwell stocks the three current 50mm gearboxes P100900, P102730 and P12436; other models need a retrofit kit. Where several ratios share one body, the ratio is stamped on the gearbox body or engraved on the wormwheel hub.
• Current (outsourced) gearboxes have the 4 × M6 cap screws holding the two halves fitted from above (heads on the top side); the earlier Maxwell-assembled ones had them fitted from below, recessed into the body.
• Where gears are needed, only a complete replacement gearbox is supplied. With no service these gearboxes are prone to fail after around 5 years.
• Corroded output shaft seal housing: replace the gearbox top – kit P101633 (800 & 1200 100TDC) or P101624 (1000, 1500, Freedom, RC8, RC10). On gearboxes built before 2010 (cap screws from below) fit the longer cap screws and nuts supplied, as the new tops are not threaded.
• Bearings: sintered bronze bushes, nominal 40.05 ± 0.05mm, available individually (3145); deep groove bearings as kit P90007 with circlips. The three lip seals come as kit P90006 with sight glass and O-ring. Use a service tool or sleeve to fit the input shaft seal so the drive slot does not damage it.
• Oil: approximately 75ml; fill to just cover the top of the wormwheel teeth with the gearbox level (1/2 – 3/4 on the sight glass).
• All current 50mm-wormbox windlasses except the HRC10 fix gearbox to spacer tube with a castellation; on the discontinued 800, 1200 and pre-2007 500 models the spacer tube was part of the gearbox (spacer tubes still stocked). In 2007 the castellation on the gearbox top moved, rotating the assembled position by 15° – only a problem in very tight spaces.

Gearbox replacement table

Gear Oil Type & Quantities

• Maxwell fills with Castrol Alpha SP320, an industrial gear oil of ISO weight 320, usually sold only in 20 liter drums.
• Any SAE gear oil of 90 to 110 weight can replace it (gear oil grades differ from motor oil grades: 90wt gear oil is not 90wt motor oil).
• Ideally use a sulphur-free oil, since sulphur corrodes the bronze wormwheel; otherwise prefer API GL2 – 4 over GL5, which carries about double the additive concentration. Avoid GL5.

RC Range Optional Extras

Insulating gaskets isolate the deckplate from aluminium hulls; studs and fasteners must also be insulated with washers and/or spacers not supplied by Maxwell.

RC8 service grease points

• Grease top and bottom faces, the shaft where the chainwheel turns, the clutch face and mating chainwheel surface; clean and grease (or anti-seize) the thread.
• Silicone ‘O-ring’ grease on the bearing surface and quad ring seal. The lower clutch cone is pressed on: do not remove it.
• Clear the gearbox drain slots and wash salt off the seal; thin coat of grease on the spacer-gearbox face (excess blocks the drain); anti-seize on key, keyway and gearbox bore; clean and protect the gearbox input and the motor.
• Anti-seize: non copper based paste. Grease: lithium complex, NLGI No.1 to No.3 (wheel bearing grease).

Freedom 500 / 800 Parts