508105 Outdrive Gasket Set · Fits OMC Cobra select 1986–1993, Replaces 18-2613, 39630, 911836

508105 Outdrive Gasket Set · Fits OMC Cobra select 1986–1993, Replaces 18-2613, 39630, 911836

GHMarine outdrive gasket / drive installation set for select OMC Cobra drives — OEM kit 508105. BOM: 911836 outdrive gasket ×1 (cross 18-2918) + 911823 outdrive seal ×1 (cross 18-2996) + 911851 O-ring ×2 (cross 18-7153). Kit-level crosses 18-2613, 39630, 9-62605, 85105. This is a gasket/seal/O-ring set — not a full transom bellows service pack.

Need only the gimbal bearing rear oil seal 3852548 → GH 23BK487. Need the gimbal bearing → GH 20GK001 (3853807). It is not Volvo SX 1994+ gasket family 3852560 / 18-2699, and not a MerCruiser kit sold as the primary fit.

Which set is this?

It is the Cobra outdrive mounting gasket set used when you reinstall or reseal the drive at the mounting face — one gasket, one seal, and two O-rings as listed above. Count those four pieces (1+1+2) in the carton.

It is not a full bellows kit (U-joint / exhaust / shift), not gimbal bearing 3853807, not single rear oil seal 3852548 alone (GH 23BK487), not Volvo SX 1994+ gasket 3852560, and not a water-inlet hose pack.

Signs you need this gasket set

• You are pulling or reinstalling an OMC Cobra drive (about 1986–1993) and the EPC / old kit shows 508105 — mounting gasket, seal, and O-rings are due together.
• The old mounting gasket (911836) is crushed or leaking at the drive-to-transom face, and the matching seal / O-rings are also worn.
• You almost ordered a full bellows + bearing photo pack — stop: this carton is gasket + seal + two O-rings only.
• Divert: only rear oil seal 3852548 → GH 23BK487. Bearing only → GH 20GK001. Volvo SX 1994+ gasket family → not this page.

Will it fit my drive?

This set is Compatible with select OMC Cobra outdrive mounting gasket applications about 1986–1993 that specify 508105. Original kit number decides fit — do not expand to Volvo SX 1994+ (that family uses different numbers such as 3852560).

*Representative dual-table band. Final fit = OEM 508105 on the old kit / EPC. Not for Volvo SX 1994+ gasket families. Not a MerCruiser primary fit page.

OEM & swap numbers

Parent OEM 508105. Contents: 911836 ×1 + 911823 ×1 + 911851 ×2. Kit crosses 18-2613, 39630, 9-62605, 85105. Child crosses: gasket 18-2918, seal 18-2996, O-ring 18-7153.

Wrong part? Read before you order

• NOT single gimbal rear oil seal 3852548 (GH 23BK487)
• NOT gimbal bearing 3853807 (GH 20GK001)
• NOT U-joint / exhaust / shift bellows kits
• NOT Volvo SX 1994+ gasket 3852560 / 18-2699
• NOT MerCruiser kit 802172A1 as a drop-in primary fit
• NOT a full transom bellows + hose + bearing service pack

What ships in the box

• 1 × Outdrive gasket (911836)
• 1 × Outdrive seal (911823)
• 2 × O-ring (911851)

Gallery note: some older photos show a full transom multi-piece layout (bellows, hose, bearing). The sold BOM is four pieces from kit 508105 — gasket + seal + two O-rings. Count those parts; do not expect bellows or a bearing in this carton.

Often ordered with related SKUs

• Gimbal bearing rear oil seal → GH 23BK487 (3852548)
• Gimbal bearing → GH 20GK001 (3853807)
• U-joint bellow → GH 18B5002 (3854127)

Install tips (drive mounting set)

OMC Cobra drive installation / mounting-face reseal. Cold engine; support the boat and drive; disconnect battery; follow the OMC service procedure for drive removal and gasket set replacement. This is not an exhaust-bellow service job — do not copy a bellows template. Confirm kit 508105 before install.

1. Confirm EPC / old kit is 508105 for OMC Cobra about 1986–1993 — not SX 1994+ 3852560 and not a bellows pack.
2. Lay out all four pieces: gasket 911836, seal 911823, two O-rings 911851.
3. Clean mating faces; install each seal/gasket/O-ring in the positions shown in the service manual.
4. Reinstall the drive; torque fasteners to the manual specification; check for leaks before returning the boat to service.

FAQ

What is in this gasket set?

Four pieces from 508105: 911836 gasket ×1, 911823 seal ×1, and 911851 O-ring ×2.

Is this a full transom bellows kit?

No. It is an outdrive mounting gasket/seal/O-ring set only — no U-joint, exhaust, or shift bellows.

Is this the same as 23BK487?

No. 23BK487 is the single rear oil seal 3852548. This page is kit 508105 with four pieces.

Will this fit Volvo SX 1994 and newer?

No. SX 1994+ uses a different gasket family (e.g. 3852560). This set is for select OMC Cobra about 1986–1993 with OEM 508105.

Is 802172A1 a replacement for this?

Do not treat 802172A1 as a primary drop-in for this Cobra set. Match OEM 508105 / the listed kit crosses instead.

Do photos show only the gasket set?

Some gallery shots may show a full multi-piece transom layout. The sold BOM is gasket + seal + two O-rings.

Please note

Aftermarket replacement by GHMarine. Not affiliated with engine manufacturers named above. "Compatible with", "Replaces", and cross-ref numbers identify the 508105 outdrive gasket set — always confirm OEM 508105, carton contents (911836 + 911823 + 911851×2), and drive model before ordering.