United States / North American reference
Verified specifications
Values are manufacturer-published or faithfully converted from the cited manufacturer record. Manufacturer-published dual units are retained where available, and the basis column travels with every value.| Specification | Metric | Imperial | Standard / configuration |
|---|---|---|---|
| Net engine power | 186 kW | 249 hp | At 1,800 rpm |
| Operating-weight range | 18,709–18,744 kg | 41,246–41,324 lb | Published configuration range |
| Bucket-capacity range | 3.1–3.6 m³ | 4.0–4.75 yd³ | Published general-purpose range |
What the specifications mean
A narrow published weight range still needs build-sheet confirmation.
Bucket volume alone cannot determine payload without material density.
Net power and the stated engine speed help keep the comparison basis visible.
Configurations and options to verify
- Standard and high-lift arms require separate tipping-load and clearance data.
- Tires, coupler, bucket and guarding change final mass and dimensions.
- Payload and scale systems should be checked for function and calibration.
Used 644 P-Tier inspection priorities
- Check centre articulation, steering cylinders, oscillation points and driveline play.
- Inspect matched tire size, type, cuts and remaining tread; price a complete set where mixing is unsuitable.
- Load the hydraulics and inspect lift-arm, bucket, bellcrank and coupler pins.
- Review transmission, axle, brake, cooling and emissions-system service records.
Hours, condition and ownership cost
Hours are context, not a condition grade. Duty cycle, idle time, maintenance evidence, wear-system measurements, structural repairs and installed technology should be evaluated together.
Cost drivers to model
- Tires, fuel, bucket wear and production cycle drive cost more than age alone.
- High-lift arms, couplers, guarding and application packages can change both value and repair exposure.
- Model payload by material density and avoid assuming the largest bucket is the most productive.
Attachments and compatibility
- Confirm coupler interface and hydraulic controls for buckets, forks, grapples and snow tools.
- Recalculate payload and stability for attachment weight and load centre.
- Use material density and bucket fill—not nominal capacity alone—to plan loading.
Transport planning
- Record weight and dimensions with the actual tires, lift arm, coupler and bucket.
- State whether the bucket or other tools will be removed and carried separately.
Manufacturer provenance
Sources and verification notes
Each exact value above points to one of these first-party records.John Deere
Open manufacturer source 644 P-Tier Mid-Size Wheel Loader
United States · exact model technical page · verified August 2026 · confidence: manufacturer-verified