Updated October 26, 2026
How surveys describe it
Wording varies by surveyor. Illustrative examples (not quoted from any real survey):
- “Drive bellows show cracking; recommend replacement.”
- “Bellows are dry and aged.”
What it is
Sterndrives pass through the transom inside rubber bellows that keep water out while the drive moves. The rubber ages and cracks, so bellows are routine maintenance items, usually replaced with the gimbal bearing.
How serious it is
A failed bellows can let water into the boat or damage the drive's moving parts. It's a moderate cost with a big downside if ignored.
In our reports this usually lands under Negotiate. Your survey's details decide.
What it typically costs
| Scope | Estimated range |
|---|---|
| 1 engine | $600–$1,000 |
| 2 engines | $1,200–$2,000 |
These are whole-job ranges drawn from published figures.[1]
- Common Mercruiser/Volvo drive
- Includes engine alignment
Estimates to help you frame a conversation with a yard, not quotes. Real prices depend on the boat, the yard, access and what's found once work starts. Confirm with your surveyor or a qualified yard.
What to ask your surveyor or yard
- Is the gimbal bearing noisy or rough?
- When was the drive last serviced?
- Is there any water in the bilge near the transom?
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Upload it and get every finding sorted into fix, negotiate, watch or ignore, with the surveyor's page and words beside each one.
Get a free previewSources
- How much should bellows change cost?, iboats forums (owner reports). Boat owners' reported prices. Accessed 2026-10-26.