Hydrasearch manufactures a full line of transmission couplers for most marine transmissions. Our couplers are cast from ductile iron and machined to SAE J755 specifications. Most of our couplers are machined with our universal bolthole pattern and are supplied with mounting hardware. We also offer custom machining for any couplers we do not standardly produce. We carry an extensive inventory in order to better supply our distributor's and OEM's demands.

Unit of Measure



N/A Borg Warner Hurth Newage

Coupler Type

N/A Solid

Flange Diameter

N/A 5 in

Shaft Range

N/A 1 to 2 in

Number of Bolts

N/A 4

Bolt Size

N/A 7/16 in

Bolt Circle

N/A 4-1/4 in

Pilot (M)

N/A 2-1/2 x 3/32 in

Overall Length

N/A 2-5/8 in



All transmission couplings require proper fitting & facing to the propeller shaft to ensure concentricity. Hydrasearch couplings are machined to SAE J755/756 specifications and require specific machinery and tooling to properly install. It is strongly recommended this work be performed by a qualified machine shop.

In order to ensure proper function of products, it is strongly recommended that each part is inspected and serviced monthly. Inspection should include, but not be limited to, visible damage, excessive wear, and proper bonding. It is also recommended that a naval engineer is consulted for proper application of hardware. Failure to properly maintain your product may result in catastrophic failure and/or loss of life.



N/A   Cancer and Reproductive Harm