Transom Bellows Seal Kit for MerCruiser Bravo I / II / III — 30-803100T1 | GH Marine

GH MARINE / BELLOWS & RELATED PARTS

About this part

This transom bellows seal kit is intended for transom bellows and seal service on specified MerCruiser Bravo I, Bravo II, Bravo III, and Blackhawk sterndrives. Fitment depends on the sterndrive model, model year, and serial number range rather than the engine alone. When comparing reference kits, verify both the drive serial number and the required gimbal-bearing version before ordering.

Match the application

This transom bellows seal kit applies to MerCruiser Bravo I, Bravo II, and Bravo III sterndrives from 1988 and up within serial number range 0B664190 and up, as well as MerCruiser Blackhawk sterndrives from 1994–1995 within serial number range 0F186717 and up.

Identify the sterndrive assembly rather than just the engine model. Check the drive model designation, production year, and exact serial number on the drive housing or transom assembly tag against the records below.

• MerCruiser · Bravo I

  Year: 1988 & Up

  Serial number: 0B664190 & Up

  For MerCruiser Bravo I sterndrives within the stated year and serial number boundary.

  Application match

• MerCruiser · Bravo II

  Year: 1988 & Up

  Serial number: 0B664190 & Up

  For MerCruiser Bravo II sterndrives within the stated year and serial number boundary.

  Application match

• MerCruiser · Bravo III

  Year: 1988 & Up

  Serial number: 0B664190 & Up

  For MerCruiser Bravo III sterndrives within the stated year and serial number boundary.

  Application match

• MerCruiser · Blackhawk

  Year: 1994-95

  Serial number: 0F186717 & Up

  For 1994–1995 MerCruiser Blackhawk drives within the stated serial number boundary.

  Application match

Numbers to compare

Use the reference numbers below to help identify your service kit or individual related references. Similar or shared cross-reference numbers do not automatically mean all kit versions or sub-component packages are interchangeable across every configuration.

Primary OEM kit references

Aftermarket kit references

Additional associated & limited-relation references

The following numbers appear in the cross-reference records for this listing. Some numbers may represent individual sub-components, related service items, or alternate kit versions rather than a complete direct equivalent to the full kit.

Technical details

Supplied contents

• Transom bellows seal kit

If your repair requires a specific gimbal-bearing design (such as a sealed versus greasable bearing) or specific individual sub-components, confirm the exact package contents before disassembly.

Workshop sequence

General workshop guidance only; use the service procedure for your exact drive or engine configuration.

1. Verify the sterndrive model (Bravo I, II, III, or Blackhawk), production year, and serial number against the service manual and your parts selection before starting work.
2. Isolate the battery and propulsion systems, secure the vessel out of the water, and properly support the sterndrive assembly for removal according to factory instructions.
3. Before removing existing bellows, seals, and hoses, note the routing, fold orientation, clamp screw positions, and connection interfaces on the gimbal housing and bell housing.
4. Clean and inspect all mating flanges, grooves, passages, and adjacent transom assembly surfaces for corrosion, pitting, or old adhesive residue.
5. Check the condition and design of the gimbal bearing (greasable vs. sealed configuration) and verify alignment with the grease passage or plug configuration on the housing.
6. Fit the new bellows and seals without twisting or pinching the convolutions, following the MerCruiser service manual for required adhesives, special tools, and clamp positioning.
7. Complete sterndrive reassembly, check drive alignment and shift operation, and inspect all transom seals for proper seating before returning the vessel to service.

Before reassembly

• Confirm that your sterndrive serial number meets the minimum serial threshold (0B664190 & Up for Bravo I/II/III; 0F186717 & Up for 1994–1995 Blackhawk).
• Compare the removed components and reference numbers (30-803100T1 and related cross-references) against the supplied parts prior to applying any sealants or adhesives.
• Verify the gimbal bearing type required for your transom assembly, especially when cross-referencing between sealed (18-8219) and greasable (18-8212-1) kit designations.
• Inspect the bell housing and gimbal ring mounting surfaces, water passage interfaces, and shift cable routing path according to your drive service manual.

Questions from the workshop

About GH Marine

GH Marine focuses on bellows and related marine service parts. Compare the application details, reference numbers and supplied contents together to select the part for your repair.

Delivery information

Estimated delivery: 7–15 calendar days.

Planning a repair for a particular date? Contact GH Marine before ordering to discuss delivery to your destination. Check that your delivery address and contact details are complete when placing your order.

For a delivery question about an existing order, have your order number and delivery destination ready when you contact GH Marine.

Warranty and assistance

Contact GH Marine for the warranty terms applicable to this product and assistance with a product issue.