Volvo Penta 3593663 Saildrive Propeller Shaft Sealing Ring (Superseded by 24940252)

Volvo Penta 3593663 – Saildrive Propeller Shaft Sealing Ring

Part Number: 3593663
Brand: Volvo Penta
Official Part Type: Sealing Ring – Propeller Shaft, Saildrive
System: Saildrive / Reverse Gear – Propeller Shaft Seal Assembly
Diagram Position: Position 16 in the lower gear / saildrive propeller shaft seal group
Superseded By: 24940252 – this is the current active OEM reference. If your parts lookup returns 3593663, the current ordering number is 24940252.

What This Part Does

This sealing ring sits behind the propeller on the saildrive propeller shaft and protects the saildrive gearbox from water intrusion. A failed or worn seal at this location allows water into the gear oil, which leads to accelerated bearing and gear wear. These seals are typically installed in pairs at the prop shaft seal location — confirm the quantity required for your specific assembly before ordering.

Compatible Applications

• Volvo Penta 120S, 120S-B, 120S-D, 120S-E
• Volvo Penta 130S, 130S-B, 130S-C, 130S-D
• Volvo Penta 130SR, 130SR-A, 130SR-B, 130SR-C, 130SR-D
• Volvo Penta 150S, 150S-B, 150S-C, 150S-D
• Volvo Penta 150SR, 150SR-B, 150SR-C, 150SR-D
• Volvo Penta MS2B-A, MS25S-A, MS25SR, MS25SR-A
• Engines with matching saildrive or reverse gear: 2001, 2002, 2003, MD11, MD17, MD2010, MD2020, MD2030, MD2040, MD22, TMD22

Serial Number Notice: Fitment depends on the exact saildrive model, reverse gear assembly, propeller shaft arrangement, and serial number range. Always confirm using your engine or saildrive serial number and the current Volvo Penta parts diagram before ordering.

Superseded / Replaced By

Original part number 3593663 has been superseded by 24940252. Use 24940252 as the current OEM ordering number. Both numbers refer to the same sealing ring position in the saildrive propeller shaft seal assembly.

Cross-References & Alternate Part Numbers

• 24940252 (current Volvo Penta superseding number)
• 851979 (related reference)
• 873108 (related reference)
• REC3593663 (aftermarket reference)

Dimensions & Weight

Approximate weight: 0.02 kg per seal. Exact seal dimensions should be verified against the Volvo Penta saildrive or lower gear schematic for your specific assembly and serial number.

Kit Contents

Single sealing ring. Sold individually. Note: two sealing rings are typically required at the propeller shaft seal location — confirm the quantity for your specific saildrive assembly before ordering.

Service Interval

Inspect propeller shaft seals during annual saildrive service or whenever gear oil is changed. Replace immediately if water contamination is found in the gear oil, or if the seal shows hardening, cracking, or damage from fishing line or debris.

When to Replace

• Water contamination found in the saildrive gear oil
• Visible seal damage, hardening, or cracking
• Fishing line or debris wrapped around the propeller shaft
• Oil leakage at the propeller shaft seal location
• During scheduled saildrive lower gear service

Installation Notes

• Confirm quantity required — two sealing rings are typically used at this location
• Inspect the propeller shaft surface, seal bore, and bearing housing before installing new seals
• Check gear oil condition and related O-rings while the assembly is apart
• Press seals in squarely and to the correct orientation for your specific saildrive or gear assembly
• Pressure or vacuum test the assembly where required before returning to service

Technical FAQ

How many sealing rings do I need?
Two sealing rings are typically required at the propeller shaft seal location on Volvo Penta saildrive assemblies. Confirm the exact quantity in the Volvo Penta parts diagram for your specific saildrive model and serial number before ordering.

My parts lookup shows 3593663 as discontinued — what do I order?
Order 24940252. This is the current active Volvo Penta OEM number that supersedes 3593663. Both numbers refer to the same sealing ring position.

What causes these seals to fail prematurely?
Fishing line wrapped around the propeller shaft is the most common cause of early seal failure. Even a small amount of line can cut through the seal lip quickly. Inspect the shaft carefully whenever the boat has been in areas with fishing activity.

Parts Desk Insights

The most common mistake with this seal is ordering one when two are needed. The prop shaft seal stack on these saildrive units uses a pair of sealing rings, and it is easy to miss that detail when looking at a parts diagram quickly. Confirm the quantity before you start the job — having to reopen the lower gear because one seal was missed is avoidable. Also worth checking: if there is any sign of fishing line damage at the shaft, inspect the shaft surface carefully before installing new seals. A grooved or scored shaft will cut through a new seal quickly.