3304 AND 3306 MARINE ENGINES Caterpillar

All current twin disc production marine gears can be backdriven (propeller windmilling with dead engine) under the following conditions, provided that vessel speed does not exceed normal maximum propulsion speed of the vessel.

For intermittent backdriving, such as:

a. Sailboat auxiliary (short trips).

b. Towing purse boats in seining operations.

1. Start the engine and operate the marine gear in neutral, at normal oil pressure, for a minimum of three minutes. Do this once every 12 hours for models MG506 and MG509, and once every 24 hours for all others.

2. Maintain oil level the same for backdriving as for normal propulsion or, keep level above FULL mark on dipstick.

For continuous backdriving, such as:

a. Sailboat auxiliary (long trips).

b. Towing to deliver a boat.

c. Towing home a boat with engine trouble (long trip - more than a day).

1. Operate in neutral with oil at normal oil pressure for a minimum of three minutes every eight hours for models MG506 or MG509, and every 12 to 14 hours for all other models.

2. Fill the marine gear with oil until level touches input shaft, on engine centerline.

3. Lock the propeller shaft to prevent rotation.