Quick checks before you begin
- Stop and isolate the machine, prevent restart and wait for all movement to stop before access. Secure raised units with the prescribed mechanical supports.
- Do not run a damaged mechanism to reproduce a symptom or take a photograph. Pressurized, spring-loaded and heavy assemblies require qualified service and the complete procedure.
- Keep unit identity, component location and repair history with every photograph and measurement.
Keep the starting position and complaint
Record which unit is affected, when the behavior occurs and whether work was recently done on the shoe, linkage, bracket or sensor. Take an overview before authorized disassembly changes the relationship of the parts.
Do not test a suspected fault by standing under an unsupported unit or forcing the mechanism. Use the specified isolation and mechanical supports before access.
- Identify the height-sensing system
Confirm the relevant structure before comparing parts.
Inspect each connected part as a separate object
The two electronic linkage illustrations differ in their parts and layout. Do not copy fastener, spacer or spring placement from the other style merely because the sensor looks similar.
| Object | Useful observations | Not established by the observation |
|---|---|---|
| Shoe and guard | Damage, missing hardware and evidence of impact | The sensor calibration or hydraulic condition. |
| Linkage, pivots and spring | Visible distortion, missing retaining parts and changes after repair | A correct linkage length or spring setting. |
| Bracket and sensor mounting | Damage, looseness and the installed relationship | Electrical operation or a confirmed sensor failure. |
| Connector and harness | Visible damage and whether earlier work disturbed routing | Supply voltage, signal values or controller condition. |
Give the workshop enough information to separate the causes
A replacement should follow the technician’s finding. If the mechanism remains damaged or the mounting is uncertain, another sensor alone cannot establish a completed repair.
- Identify the component from the actual assembly or parts record, not the figure label.
- Supply a whole-linkage view and close photographs of the damaged connection.
- List removed and replaced parts separately, keeping the original hardware identified.
- Record previous adjustments, impacts and calibration work if known; do not fill gaps with assumptions.
Ask for the mechanical check and the required calibration result
TM2109 requires electronic height-sensor calibration through the machine Diagnosis and Test Manual after replacement. Mechanical reassembly and electronic calibration are separate handover items.
Until the machine-specific procedure and result are available, retain calibration as pending. This guide does not specify test voltages, diagnostic codes, travel limits or a controller sequence.
- Repair handover checklist
Keep unresolved checks visible before return to work.
- Ask about an identified replacement part
Send the installed reference, unit identity and mounting photographs. A symptom alone does not establish fitment or availability.
Technical basis for this article
The article paraphrases and organizes the sources below. It does not copy a service manual, and it does not replace the current documentation for the exact machine.
- TM2109 (20 July 2020), Section 110, Group 10John Deere Des Moines Works | repair manual
Source scope: PDF pages 200–203; printed 110-10-1–4, including both linkage illustrations. Original inspection and service-handover summary, not the complete repair procedure. Confirm current service information for the installed unit. The purchased manual and its illustrations are not hosted here.
Questions buyers and technicians ask
Should I replace the sensor whenever height control behaves incorrectly?
Not from the symptom alone. The installed structure, mechanical connections and machine-specific diagnosis need review.
Can I copy the linkage setting from another unit?
Do not assume it applies. Confirm the structure and use the complete applicable service and calibration information.