T-H Marine CMC Bottom Transom Washer Plate, 3/8 Inch 6061-T6 Aluminum, 9-7/8 Inch Hole Centers

The T-H Marine CMC Bottom Transom Washer Plate is a load-distributing backing plate designed to be installed on the lower side of the transom where an outboard, jack plate, or Power-Lift bracket is bolted through. It is machined from strong 3/8 inch 6061-T6 alloy aluminum, not cast aluminum, giving it the strength to hold up under the high clamping loads of performance engines without deforming or cracking the way lighter cast plates can.

Its main job is to spread bolt loads evenly across the transom surface. Without a washer plate, mounting bolts can concentrate pressure into small contact points and, over time, begin biting into the transom material, compressing the wood or coring underneath and loosening the mounting hardware. By sandwiching a rigid aluminum plate between the bolt heads or nuts and the transom, the CMC Bottom Transom Washer Plate keeps that load spread out, which helps protect the transom and keep the mounting hardware tight, particularly on high performance engines that put more stress on the transom during hard acceleration and trim changes.

The plate uses a 9-7/8 inch hole center pattern. It is intended for use as the bottom-side counterpart in a transom mounting setup and installs using standard hand tools alongside the existing mounting hardware.

Specifications

• Brand: T-H Marine CMC
• Manufacturer Part Number: 20032
• Category: Jack Plate Accessories
• Material: 3/8 Inch 6061-T6 Alloy Aluminum (Not Cast Aluminum)
• Hole Centers: 9-7/8 Inches
• Mounting Position: Bottom (transom underside)
• Weight: 0.8 pounds
• UPC: 733572020032

Fitment

Universal bottom-side transom washer plate sized to a 9-7/8 inch hole center pattern; not restricted to a specific engine make or model in available records.

Replaces (OEM)

No OEM cross-reference numbers are listed for this part.

Frequently Asked Questions

What is the CMC Bottom Transom Washer Plate used for? It is a backing plate that sits against the underside of the transom to spread out the clamping load from outboard, jack plate, or Power-Lift mounting bolts, part number 20032 in 3/8 inch 6061-T6 alloy aluminum.

What hole pattern does the 20032 washer plate use? The bottom transom washer plate uses a 9-7/8 inch hole center pattern.

Is this washer plate cast aluminum? No, the T-H Marine CMC Bottom Transom Washer Plate is made from 3/8 inch 6061-T6 alloy aluminum, not cast aluminum, which gives it more strength under high mounting loads.

How much does this transom washer plate weigh? The CMC Bottom Transom Washer Plate weighs 0.8 pounds.

Why do I need a washer plate on my transom? A washer plate spreads bolt loads evenly across the transom instead of letting them concentrate at the bolt heads, which helps stop mounting bolts from biting into and compressing the transom, especially on high performance engines.

Is there a difference between the top and bottom transom washer plate? Yes, the part described here (20032) is the bottom-side washer plate, installed on the underside of the transom; a separate top-side washer plate with a different hole spacing is sold as its own part for use on the opposite face of the transom.

Does the 20032 washer plate come with mounting bolts? The listed contents are the aluminum washer plate itself; it is designed to be used with your existing transom mounting hardware rather than a separate bolt kit.

Will this washer plate work with a jack plate or Power-Lift bracket? The CMC Bottom Transom Washer Plate is designed as a load-distributing backing plate for transom-mounted hardware such as jack plates and Power-Lift brackets, based on its 9-7/8 inch hole spacing.

Is the CMC Bottom Transom Washer Plate suitable for high performance engines? Yes, its 3/8 inch 6061-T6 aluminum construction is intended specifically to more evenly distribute mounting loads on high performance engines.

What material is the 20032 transom washer plate made of? It is made of strong 3/8 inch 6061-T6 alloy aluminum, specifically not cast aluminum, for added durability under load.