T-H Marine Outboard Motor Transom Pads/Support Plates

T-H Marine Transom Support Plates: Purpose-Built Transom Protection

When you mount an outboard motor, the forces generated by the engine — vibration, torque, and thrust — concentrate around a small cluster of mounting bolts on your transom. Over time, those bolts can bite into the transom material, compress the fiberglass or wood core, and cause cracks or structural weakness that is expensive to repair. That's exactly the problem that T-H Marine's transom support plates are designed to solve.

Outboard motor transom pads and support plates act as load-spreading intermediaries between the motor's mounting bracket and the boat's transom. T-H Marine, a family-owned company that has been serving the marine industry since 1975, applies that same philosophy of practical, durable engineering to its line of transom support plates — making them a trusted choice for boaters looking to protect their investment.

What Sets T-H Marine Transom Support Plates Apart

T-H Marine offers two primary transom support plate models, differentiated by bolt hole pattern to ensure compatibility with a wide range of outboard motor setups:

• TSP-1-DP — Features a 13" bolt hole pattern for top bolt hole mounting, the standard configuration on most larger outboards.
• TSP2DP — Features a 10" bolt hole pattern for lower bolt hole mounting, covering standard configurations on smaller or mid-range engines.

Both plates are constructed from high-quality cast aluminum at a 3/8" thickness, a robust gauge that provides meaningful rigidity without adding unnecessary weight to the stern. The cast aluminum construction is engineered to distribute the stress of the motor mounting bolts evenly across the transom surface, reducing the concentration of load that leads to bolt bite, compression damage, and long-term structural fatigue.

The CMC-line machined variants, also part of the T-H Marine family, take the material a step further — machined from 6061-T6 alloy aluminum (rather than cast aluminum) for even greater precision and strength, making them particularly well-suited for high-performance engines where loads are especially demanding. These plates mount in the splashwell using the motor's existing mounting bolts, making installation straightforward for any boater with basic mechanical skills.

Why Transom Protection Matters

Many boaters overlook transom support plates until damage has already occurred. A compromised transom is not just a cosmetic issue — it can affect motor alignment, reduce steering precision, and in severe cases, create a safety risk. Installing a properly sized T-H Marine support plate during rigging or at the first sign of wear is a low-cost measure that can prevent costly transom repairs down the line.

T-H Marine's products are found on virtually every type of recreational boat built in the United States, from bass boats and pontoons to offshore fishing boats and center consoles — a testament to the brand's reputation for reliable, marine-grade hardware. Whether you're rigging a new build or reinforcing an older transom, T-H Marine's support plates deliver the durability and fit that serious boaters expect.

Browse the full range of outboard motor transom pads and support plates, or explore everything T-H Marine has to offer across their complete catalog of marine accessories.