Mercury / Mariner 30, 40, 50 and 60 HP Gearcase Gears, Shafts and Seals Exploded Diagram

Gearcase gears, shafts and seals shown in this diagram

The numbered drawing covers impeller, gear, bearing, oil seal, gasket and O-ring for Mercury / Mariner 30, 40, 50, 60 HP (4-cylinder) EFI / 40 carburettor (3-cylinder). Use the illustration to locate the assembly position, then use the schedule to resolve the product code and OEM reference.

Choose the correct gearcase component

Work through the relevant subassembly before choosing a replacement. The numbered position and exact reference are more reliable than component shape, broad horsepower range or model-family similarity.

Water pump and impeller parts

Water-pump housings, impellers, plates, gaskets and seals must be matched as individual scheduled parts or as an explicitly listed service kit. Do not assume that parts from a similar-horsepower outboard share the same pump assembly.

Gears, shafts and bearings

Match gears, shafts and bearings by the numbered position and reference. Where ratio, rotation, shaft length or production changes are stated for a row, those limits take priority over the broader model heading.

Seals, gaskets and O-rings

Individual seals and gaskets are not automatically complete rebuild kits. Check the mating surfaces, the location shown on the drawing and the exact cross-reference before selecting single components or a scheduled kit.

How to use the diagram and parts schedule

1. Confirm that the equipment is Mercury / Mariner 30, 40, 50, 60 HP (4-cylinder) EFI / 40 carburettor (3-cylinder) and check any page-level year or serial scope.
2. Find the required component on the exploded drawing and note its numbered callout.
3. Match the callout to the product code and OEM cross-reference in the parts schedule.
4. Apply every model, serial, ratio, side, material and configuration note shown for that row.
5. Compare the selected replacement with the removed part before installation.

Fitment and cross-reference checks

The page-level route is Mercury / Mariner 30, 40, 50, 60 HP (4-cylinder) EFI / 40 carburettor (3-cylinder). It helps customers reach the correct drawing, but it does not make every product in the schedule interchangeable across every version of that model family.

An OEM number is an identification cross-reference. Confirm the exact product code, model designation and any bounded selection information before ordering. A product may also appear under another make or model only where that separate SKU-to-application fitment is independently supported.