Overview
This quick-reference guide covers John Deere Z925A ZTrak Pro Series zero-turn mowers equipped with a 54-inch 7-Iron, 54-inch Mulch On Demand, or 60-inch 7-Iron mower deck.
The Z925A does not use one universal PTO clutch. Deere's early maintenance reference identifies TCA16999, now serviced through the TCA19141 / TCA20380 heavy-clutch path. A separate, confirmed late-serial path applies to the 54-inch Mulch On Demand deck at serial number 020001 and higher: TCA20604 / TCA21167. Select standard-deck and EFI configurations can instead use the heavier TCA20605 / TCA21166 / TCA22879 / AUC11007 family.
Because those clutch families are physically different, use the mower PIN, deck configuration, and number stamped on the original clutch before ordering. Do not select a clutch from the Z925A model name alone.
Quick Answer
| Z925A Configuration | Confirmed PTO Clutch Path | PTO Direct Product | Fitment Note |
|---|---|---|---|
| Original clutch marked TCA16999, TCA19141, or TCA20380 | TCA16999 → TCA19141 → TCA20380 Warner 5228-3 |
TCA20380 PTO Clutch | Earlier heavy-clutch family used on select Z925A configurations. Match the original clutch number. |
| 54-inch Mulch On Demand deck Serial 020001 and higher |
TCA20604 / TCA21167 Warner 5218-271 / 5218-401 |
TCA21167 PTO Clutch | This is the dealer-confirmed late-serial 54-inch MOD path. |
| Select standard 54-inch, 60-inch, or EFI configurations with a matching original number | TCA20605 / TCA21166 / TCA22879 / AUC11007 Warner 5228-38 / 5228-55 |
AUC11007 PTO Clutch | Use only when the original clutch or the Deere PIN lookup confirms this heavy-clutch family. |
Critical clutch note: Serial number 020001 does not automatically make every Z925A a TCA21167 application. The confirmed TCA21167 rule is specific to the 54-inch Mulch On Demand deck. Standard 54-inch and 60-inch machines must be matched by their original clutch number or the Deere parts catalog for the complete mower PIN.
John Deere Z925A PTO Clutch Specifications
TCA20380 Heavy-Clutch Path
- John Deere Numbers: TCA16999 / TCA19141 / TCA20380
- Warner Reference: 5228-3
- Voltage: 12 VDC
- Crankshaft Bore: 1-1/8 inches
- Pulley Diameter: approximately 6-7/8 inches
- Rotation: CCW
The TCA20380 PTO clutch replacement is the stocked replacement path when the original Z925A clutch is marked TCA16999, TCA19141, or TCA20380.
TCA21167 Late 54-Inch MOD Path
- John Deere Numbers: TCA20604 / TCA21167
- Warner References: 5218-271 / 5218-401
- Voltage: 12 VDC
- Crankshaft Bore: 1-1/8 inches
- Pulley Diameter: approximately 6.61 inches / 6-5/8 inches
- Rotation: CCW
The TCA21167 PTO clutch replacement fits the confirmed Z925A 54-inch Mulch On Demand configuration at serial number 020001 and higher when the original clutch path matches TCA20604 or TCA21167.
AUC11007 Heavy-Clutch Path
- John Deere Numbers: TCA20605 / TCA21166 / TCA22879 / AUC11007
- Warner References: 5228-38 / 5228-55
- Crankshaft Bore: 1-1/8 inches
- Pulley Diameter: approximately 6-5/8 inches
- Rotation: CCW
This family appears on select Z925A standard-deck and EFI configurations. It is not interchangeable with TCA21167 solely because both can appear in Z925A searches. Match the original clutch number and Deere equipment record. Contact to inquire about product.
John Deere Z925A 54-Inch 7-Iron and 54-Inch MOD Deck Parts
| Deck Part | OEM Part Number Path | Quantity | PTO Direct Product | Fitment Note |
|---|---|---|---|---|
| Mower Deck Belt | TCU26295 | 1 | Contact to inquire about product | Earlier 54-inch path; specifically confirmed on the 54-inch MOD deck through serial 020000. Effective length approximately 166.85 inches. |
| Mower Deck Belt | TCU29453 | 1 | Contact to inquire about product | Later 54-inch path beginning at serial 020001. Deere lists an effective length of approximately 166.50 inches. |
| Standard Side-Discharge Blades | M144652 | 3 | Contact to inquire about product | Confirmed in Deere's Z900A 54-inch deck maintenance reference. |
| Spindle Assembly | TCA17517 → TCA20639 → TCA24880 | 3 | TCA24880 Spindle Assembly | Match the original spindle number and mounting arrangement before ordering. |
| Blade-Drive Sheave | TCU26966 | Confirm by diagram position | Contact to inquire about product | 54-inch sheave path; do not substitute the 60-inch TCU26967 sheave. |
| Mower Deck Idler | TCA17524 / AUC16478 | Confirm by diagram position | AUC16478 Deck Idler | Match the original number, pulley position, diameter, and belt-contact surface. |
| Secondary Idler | TCA17135 | Confirm by diagram position | Contact to inquire about product | Deere lists more than one idler position; do not order by appearance alone. |
| Belt-Tension Spring | TCU27010 | 1 | Contact to inquire about product | Confirmed 54-inch deck extension-spring path. |
54-inch deck note: The Z925A was sold with both a standard 54-inch 7-Iron deck and a 54-inch Mulch On Demand deck. Those deck names matter most when identifying the PTO clutch. The confirmed late TCA21167 clutch rule applies to the 54-inch MOD deck, not automatically to every 54-inch Z925A.
John Deere Z925A 60-Inch 7-Iron Deck Parts
| Deck Part | OEM Part Number Path | Quantity | PTO Direct Product | Fitment Note |
|---|---|---|---|---|
| Mower Deck Belt | TCU26297 | 1 | Contact to inquire about product | Earlier 60-inch deck-belt path through serial 020000. Deere lists an effective length of approximately 180 inches. |
| Mower Deck Belt | TCU29454 | 1 | Contact to inquire about product | Later 60-inch deck-belt path beginning at serial 020001. Deere lists a 4550 mm effective length. |
| High-Lift Blades | TCU15881 | 3 | TCU15881 High-Lift Blade Set | Use three matching 21-inch blades with the correct 7/8-inch center hole. |
| Low-Lift Blades | M133381 | 3 | Contact to inquire about product | Confirmed low-lift option for the 60-inch deck. |
| Mulching Blades | M131958 | 3 | M131958-Cross-Referenced Blade Set | The linked product includes M131958 in its replacement path; confirm the selected package and blade profile. |
| Spindle Assembly | TCA17517 → TCA20639 → TCA24880 | 3 | TCA24880 Spindle Assembly | One spindle is used at each blade station. |
| Blade-Drive Sheave | TCU26967 | Confirm by diagram position | Contact to inquire about product | 60-inch sheave path; do not substitute the 54-inch TCU26966 sheave. |
| Mower Deck Idler | TCA17524 / AUC16478 | Confirm by diagram position | AUC16478 Deck Idler | Match the original number, pulley position, diameter, and belt-contact surface. |
| Secondary Idler | TCA17135 | Confirm by diagram position | Contact to inquire about product | Identify the exact diagram position before ordering. |
| Belt-Tension Spring | TCU24629 | 1 | Contact to inquire about product | Confirmed 60-inch deck extension-spring path. |
Deck Belt Serial-Number Split
| Deck | Mower Serial Range | Deck Belt | PTO Direct Product |
|---|---|---|---|
| 54-inch 7-Iron / applicable 54-inch MOD path | Through 020000 | TCU26295 | Contact to inquire about product |
| 54-inch 7-Iron / applicable 54-inch MOD path | 020001 and higher | TCU29453 | Contact to inquire about product |
| 60-inch 7-Iron | Through 020000 | TCU26297 | Contact to inquire about product |
| 60-inch 7-Iron | 020001 and higher | TCU29454 | Contact to inquire about product |
Belt note: Match the deck tag and mower serial number before ordering. The traction-drive belt is a separate belt; Deere's earlier Z925A maintenance reference identifies it as TCU25673.
Important Fitment Check
Start with the original PTO clutch number. Use the TCA20380 path only when the original clutch is TCA16999, TCA19141, or TCA20380. Use the TCA21167 path on the confirmed late-serial 54-inch MOD configuration when the original number matches TCA20604 or TCA21167.
If the original clutch is marked TCA20605, TCA21166, TCA22879, or AUC11007, keep the mower on that heavy-clutch family. Do not substitute TCA21167 because the bore or model name appears similar.
For deck parts, distinguish the 54-inch standard deck from the 54-inch MOD deck, record the mower serial number, and use the part number from the correct diagram position. Deere changed both 54-inch and 60-inch belt paths at the 020000 / 020001 serial break.
Common PTO Clutch and Deck Symptoms
- Blades will not engage when the PTO switch is activated
- The clutch clicks but the deck belt does not begin turning
- Blades engage when cold and stop after the clutch heats up
- Deck belt slips, squeals, smokes, or repeatedly comes off
- Grinding or bearing noise from a spindle or idler pulley
- Visible pulley wobble or uneven belt tracking
- Deck vibration caused by damaged blades, bearings, or sheaves
- Uneven cutting or reduced blade speed under load
Inspect the PTO clutch, deck belt, idlers, sheaves, spindle assemblies, blades, and anti-rotation bracket as a system. A seized deck component or damaged belt path can overload a new clutch.
FAQ
What PTO clutch fits a John Deere Z925A?
There is no single universal Z925A clutch. Earlier machines can use the TCA16999 / TCA19141 / TCA20380 heavy-clutch path. A Z925A with a 54-inch Mulch On Demand deck at serial 020001 and higher uses TCA20604 / TCA21167. Select standard-deck and EFI configurations can use TCA20605 / TCA21166 / TCA22879 / AUC11007. Match the original number or the Deere PIN lookup.
Does TCA21167 fit every John Deere Z925A after serial 020001?
No. The confirmed TCA21167 application is the Z925A with a 54-inch Mulch On Demand deck at serial number 020001 and higher. Standard 54-inch and 60-inch machines must be checked by original clutch number and mower PIN.
Does TCA20380 replace TCA16999 on a Z925A?
Yes, on compatible Z925A configurations using that original clutch family. The TCA20380 replacement covers the TCA16999 / TCA19141 / TCA20380 path. Confirm the original number before ordering.
What deck belt fits a John Deere Z925A with a 54-inch deck?
The earlier 54-inch path uses TCU26295 through serial 020000. The later 54-inch path uses TCU29453 beginning at serial 020001. Confirm whether the deck is standard 7-Iron or Mulch On Demand and use the correct parts diagram.
What deck belt fits a John Deere Z925A with a 60-inch deck?
The earlier 60-inch path uses TCU26297 through serial 020000. The later 60-inch path uses TCU29454 beginning at serial 020001.
What blades fit the John Deere Z925A 60-inch deck?
Deere's Z900A maintenance reference lists TCU15881 high-lift, M133381 low-lift, and M131958 mulching blades for the 60-inch deck. Use three matching blades and confirm the original profile.
What spindle fits a John Deere Z925A?
The deck spindle service path begins with TCA17517 and continues through TCA20639 to TCA24880. Confirm the original number and mounting setup before ordering.
Why are multiple idlers listed?
The 7-Iron deck uses different pulley positions. Deere's maintenance reference lists TCA17524 and TCA17135, and the current stocked AUC16478 idler follows the TCA17524 replacement path. Match the original number and diagram position rather than ordering by appearance.
Related John Deere Quick References
- John Deere Z910A PTO clutch and deck parts quick reference
- John Deere Z920A PTO clutch and deck parts quick reference
- John Deere Z540M PTO clutch and deck parts quick reference
- John Deere Quick Reference Library
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