Overview

The Garmin 010-13348-00 is a stainless steel transducer jam nut for the GT17M-THF thru-hull transducer. It threads onto the transducer housing from inside the boat to clamp the installation stack and keep the housing seated once everything is sealed and tightened.

This is the right part to replace a nut that was lost during a haul-out, damaged during removal, or no longer tightens smoothly on the housing threads. On a GT17M-THF installation, the jam nut is tightened with a 108 mm (4 1/4 in.) wrench or an adjustable wrench sized for that nut.

Because this hardware is part of a below-waterline fitting, take a minute to confirm the transducer model and inspect the housing threads before reassembly. In fiberglass, avoid over-tightening; a secure fit without crushing the laminate is the goal.

Key features

• Replacement stainless steel jam nut for the Garmin GT17M-THF transducer housing
• Used on thru-hull installs to lock the transducer in position from inside the hull
• Tightening size calls for a 108 mm (4 1/4 in.) wrench or a suitably sized adjustable wrench
• Stainless steel construction that holds up well around bilge moisture and saltwater exposure
• Restores a proper mechanical clamp when the original nut is missing, damaged, or corroded

Compatibility and fit

This jam nut is specific to the GT17M-THF transducer housing and thread form. Confirm the transducer model before ordering, especially if you have multiple Garmin thru-hull transducers on board or are servicing a boat you did not rig originally.

If the GT17M-THF is installed in an aluminum or steel hull, keep the galvanic isolation parts in place when reassembling the thru-hull stack so the installation stays protected.

Installation and setup

On the GT17M-THF assembly, the jam nut goes on from inside the hull after the internal washer and spacer stack is in place, then it is tightened to secure the housing in the hull. Plan access in the bilge so you can keep the housing from turning while you snug the nut down.

After any service work below the waterline, put the boat in the water and check for seepage around the transducer before leaving it unattended for an extended period.

Use cases on board

This part makes sense for anyone servicing a GT17M-THF during a haul-out, replacing hardware that has seized over time, or reassembling a thru-hull install after pulling the transducer for inspection or bottom work.