Martyr CM852835Z Zinc Transom Bar Anode – Volvo Penta SX/DP | Saltwater
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Martyr Zinc Transom Bar Anode — Volvo Penta SX/DP | Part No. CM852835Z
Replace the transom bar anode on your Volvo Penta SX or DP sterndrive with this zinc-alloy unit from Martyr Anodes. The transom bar anode mounts across the transom bracket assembly and provides sacrificial protection for the surrounding hardware against galvanic corrosion in saltwater environments.
Zinc is the traditional choice for saltwater use. If you operate in freshwater or move between fresh and salt water, see the magnesium and aluminum alternatives linked below.
Part Information
- Part Number: CM852835Z
- Brand: Martyr Anodes
- Anode Material: Zinc
- Anode Type: Transom Bar Anode
- OEM Reference: 852835
- Best Use: Saltwater environments
Compatible Applications
- Volvo Penta SX Sterndrive — transom bar position
- Volvo Penta DP Sterndrive — transom bar position
- Saltwater operating environments
Choosing the Right Alloy
- Zinc (this part) — Saltwater use
- Aluminum — CM852835A — Saltwater and brackish water; preferred alloy for aluminum drive components and mixed-water conditions
- Magnesium — CM852835M — Freshwater use only
Related Products
- Volvo Penta SX Sterndrive Zinc Anode Kit – 3588770 — complete SX drive anode kit
- Volvo Penta SX Zinc Anode Kit VPSXKZ — alternate complete SX anode kit
Service Interval
Inspect transom bar anodes at every haulout and replace when worn to approximately 50% of original size. In high-galvanic marina environments or areas with significant stray current, inspect more frequently as depletion rates can vary based on surrounding vessels and dock wiring conditions.
Parts Desk Insights
The transom bar is one of the most exposed anode positions on a Volvo Penta sterndrive and is often the first to show significant wear. Zinc is a reliable saltwater choice for this position, but if your drive has aluminum components — which most Volvo Penta sterndrives do — the aluminum CM852835A is generally the preferred alloy: it provides equivalent protection in saltwater while being less likely to cause galvanic issues with aluminum hardware. The most common mistake we see is customers installing zinc anodes in freshwater, where zinc doesn’t corrode fast enough to provide meaningful protection. Don’t wait for this anode to fully deplete before replacing — once it’s gone, the transom bracket hardware starts corroding quickly.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.