May 7, 2026 Mowers

John Deere GX345 Manual and Mower Deck Guide

John Deere’s GX335/GX345 operator manual OMM152805 I4 calls the GX345 a garden tractor and covers machines with PIN 120001 onward. Its GX345 engine section includes coolant and cooling-system service. If a listing calls the machine air-cooled, check the installed engine before ordering parts. The manual also has separate 48-inch and 54-inch mower specifications; it cannot tell you which deck is on a particular used tractor.

Match the manual to the tractor

Read the tractor PIN and engine identification on the machine before using a specification. If the PIN is below 120001, the I4 manual is outside its stated range; find a matching edition through Deere Manuals & Training. If a label is missing or the fitted engine differs from the book, resolve the discrepancy before selecting service parts.

Identify the installed mower

Deere’s June 2015 attachment archive lists a 48C Convertible Mower (SKU21354) and a 54C Convertible Mower (SKU21394) for the non-current GX335/GX345/GX355 group. The archive notes that the appropriate front draft arm assembly may need a separate parts order with a cartoned mower. These were historical field-conversion offerings. The list cannot identify the mower on a used tractor or confirm today’s inventory.

Look for the mower’s identification mark. Compare its mounting pieces, primary belt route and parts listing with that deck before ordering a belt, blade or attachment. A 48C or 54C label alone does not establish that every required mounting part is present.

Check a used GX345

  1. Record the tractor PIN, engine identification and mower identification. Ask the seller for clear label photos if you cannot inspect them in person.
  2. With the engine stopped and cool, check for visible coolant leaks, damaged hoses and missing radiator hardware. Follow the matching Deere manual for cooling-system service; never open a hot pressurized system.
  3. Inspect the deck shell, belt guards, spindle areas and front draft arm. Ask for a demonstration of the safety-system checks described in the correct operator manual.

The reviewed Deere pages do not support a universal horsepower, fuel-use figure, towing limit, slope angle or installed mower deck for every GX345. If the machine’s identifiers conflict with its paperwork, ask a Deere parts or service specialist to identify it before buying.