This page covers the John Deere LA120 lawn tractor. The existing URL includes “21hp,” but that slug is not a substitute for the engine label or a serial-matched publication. Confirm the exact machine before using a specification or buying a replacement part.
Deere’s covers the LA100, LA110, LA120, LA130, LA140, and LA150 for PIN 10001 and higher. Confirm both the model and PIN range; earlier machines may require a different publication.
Equipment & supplies
Identification tools for LA120 Lawn Tractor
Read the machine and component markings before ordering. These inspection tools do not establish part fit.
Ullman HTC-2 inspection mirror
Read an accessible identification plate from another angle when collecting details for the matching manual.
Streamlight MicroStream pocket light
Read accessible identification and warning labels after following the machine's shutdown instructions.
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Identify the tractor and installed equipment
Record the tractor’s PIN, the engine model and serial number, and the mower deck model. The engine and deck may have their own parts diagrams and applicability ranges. If an assembly has been replaced, use the number on the installed component rather than assuming it matches the tractor’s original equipment.
Choose parts by the document’s fitment notes
- Match the PIN or serial range in the operator’s or parts manual.
- Use the engine-specific diagram for engine service parts.
- Use the deck’s model information for blades, belts, and deck components.
- For an attachment, check the specified mounting and machine limits in its documentation.
Deere’s is the starting point for manuals. Check assemblies in the ; ask a dealer to resolve an unreadable PIN or conflicting serial break instead of guessing.
Keep a short record of the identifiers and the publication used. It makes future service and parts checks faster without relying on an unverified horsepower claim.