Proper Pod Drive Maintenance

It seems like only yesterday pod drives were just a twinkle in the eye of marine propulsion engineers. But today pod drives have proliferated to a point where most major players offer one, including Volvo Penta's IPS and Cummins MerCruiser Diesel's Zeus as well as Yanmar Marine and ZF Marine. Pod motors are in use on hundreds of models of boats around the world and, in general, require significantly less maintenance than a conventional propulsion system fitted with a propeller shaft, coupler, cutlass bearing and stuffing box. Because they're joystick-controlled, pod boats don't have a bow thruster and the attendant maintenance chores. But like any mechanical device, they require preventative maintenance to keep them running at peak performance. So exactly what steps are involved? Here's a rundown.

First comes routine maintenance. The diesel component requires ample air, clean diesel fuel, adequate coolant and fresh lubricant. Every day (or when refueling) take the time to check the diesel engine's vital fluids ? pull the crankcase dipstick, check the sea strainer and coolant level and drain the fuel/water separator. On the pod drive, check the steering actuator and trim tab fluid levels. Note the level in the gear lube monitor, and check the transmission fluid level.

At about 100 engine hours, check and/or replace the sacrificial zincs; check the sea strainer (clean it if necessary); check the air cleaner for restrictions; check/adjust the seawater pump's drive belt; and check electrical connections. It's also important to inspect the battery connections and the battery electrolyte levels. On the pod drive itself, check the steering backup pump fluid level. Change the engine oil and filter. Cummins MerCruiser Diesel says using synthetic oils (engine or drive) does not increase the oil change interval.

At the one-year mark, or about 500 engine hours, the checklist grows more intensive. Diligently inspect the seawater pump, drive belt tensioner and drive belts. Flush the after cooler, gear oil cooler and heat exchanger, and check the air cleaner. Also, inspect engine mounting bolts and vibration isolators.

Whenever the boat is hauled for bottom paint or when paying a diver to scrape off barnacles and slime, take a close look at the propellers to make sure there are no nicks or gouges in the blades.

Scheduled maintenance follows a similar pattern. After 25 hours, replace the transmission fluid. Volvo Penta warns: Don't make the mistake of exceeding 30 hours.

At the 250-hour or one-year mark, whichever comes first, change the transmission and drive leg gear oil as well as steering and trim tab fluids. On models fitted with a steering fluid filter, change it. Replace any sacrificial zincs that have corroded away to less than 50 percent of their original size.

While hauled out (at least once per year or after every 500 hours of engine operation), lubricate the propeller splines and torque the propeller nuts. On the drive, check the exhaust system connections for damage or leaks. On a Volvo Penta, every five years or 1,200 hours, the propeller shaft seal needs a close inspection.

Inspect the cooling system for hoses that have become brittle or have come loose due to vibration or corrosion. Look for damaged wiring and loose electrical connectors. Inspect hydraulic system fittings and hoses for damage.

Depending on the brand and whether or not you opted for an extended protection plan, many of the procedures can be performed by a marine technician at no cost to you. As with all expensive on-board systems, create a paper trail, saving all of the work orders and receipts.

Finally, it's good practice to keep a maintenance log. It can help you troubleshoot if anything goes wrong. And, more importantly, it can boost resale price.