24V Glow Plug Caterpillar 3304 3306 3406 Replaces 3T-8706 4N-0360

This glow plug is listed for several Caterpillar diesel engines, commonly including 3304, 3306, 3406, 3408, and 3412. It’s also referenced for SR4 generator applications in certain configurations. Because equipment can be swapped/converted over time, match your engine model and part number before ordering.

This listing is for a 24V glow plug. Do not install a 12V glow plug in a 24V system (or vice-versa). If you’re unsure, check the machine electrical system or confirm the part number you’re replacing.

It replaces Caterpillar 3T-8706 and 4N-0360 / 4N0360. If your old plug matches one of these numbers, this is the correct cross-reference.

The thread size is 3/8"-24. Always start threads by hand to avoid cross-threading.

Common symptoms include hard cold starts, excessive white smoke on startup, rough idle for the first minute, and longer cranking time in cold weather. A quick check is to remove the plug and test with a multimeter—if it shows an open circuit (no continuity), it’s usually failed.

If your engine uses multiple glow plugs and one has failed, many technicians replace them as a set (or at least check the rest), since the others may be close in age and wear. If budget matters, you can replace one and test the others.