The John Deere 4720 Compact Utility Tractor is known for its power, comfort, and compatibility with a wide array of implements. Whether used for farming, landscaping, or commercial groundskeeping, it’s a workhorse. However, no machine is without issues—especially as it accrues hours.
This guide covers:
- Common John Deere 4720 problems
- Fixes and maintenance tips
- Full specs overview
- User FAQs
- Reliability insights and final thoughts
🔧 Common John Deere 4720 Problems and Fixes
1. Engine Won’t Start or Hard Starting
Symptoms:
- Engine cranks but doesn’t fire
- Delayed starts in cold weather
- No crank at all
Causes:
- Weak battery or corroded terminals
- Faulty fuel solenoid or relay
- Clogged fuel filter or gelled diesel
- Bad safety switches (seat, PTO, neutral)
Fixes:
- Clean battery terminals; load test battery
- Test fuel shutoff solenoid; replace if clicking is inconsistent
- Drain fuel system, replace filters, and use winter-grade diesel
- Test safety interlocks using multimeter
2. Hydrostatic Transmission Problems
Symptoms:
- Jerky or sluggish movement
- Whining noise under load
- No forward/reverse in high range
Causes:
- Low or dirty hydraulic oil
- Air in hydraulic lines
- Worn hydrostatic drive pump
Fixes:
- Refill hydraulic oil (John Deere Hy-Gard preferred)
- Purge air by cycling the hydro pedal at idle
- Check for leaks or damaged seals
- If whining persists, inspect hydro pump wear (may require rebuild)
3. Overheating Issues
Symptoms:
- Temperature light on dash
- Loss of power under load
- Radiator overflow
Causes:
- Dirty radiator fins
- Low coolant or failed thermostat
- Fan belt slipping or broken
Fixes:
- Clean radiator with air pressure or hose
- Refill coolant and inspect thermostat for sticking
- Tighten or replace fan belt
4. Electrical System Failures
Symptoms:
- No power to dash
- Flickering lights or gauges
- Random shut-offs
Causes:
- Blown fuse or relay
- Loose battery ground or corroded connectors
- Bad ignition switch
Fixes:
- Check and replace fuses (use OEM amperage)
- Clean and reattach ground strap to frame
- Test ignition switch continuity
5. PTO Not Engaging
Symptoms:
- Rear PTO won’t spin
- Error light on dash
- PTO shuts off under load
Causes:
- PTO switch failure
- Faulty seat sensor
- Low hydraulic pressure
Fixes:
- Replace or test PTO selector switch
- Bypass seat sensor to test functionality
- Top up hydraulic fluid and check pump pressure
⚙️ John Deere 4720 Tractor Specifications
| Category | Details |
|---|---|
| Engine | 4-cylinder Yanmar 2.4L Turbo Diesel |
| Gross HP | 66 hp |
| PTO HP (Independent) | 56 hp |
| Transmission | eHydro (3-range Hydrostatic) |
| Fuel Capacity | 13.5 gal (51.1 L) |
| Hydraulic Flow (Total) | 13.9 GPM (52.6 L/min) |
| Rear Hitch Capacity | 2,500+ lbs at 24” behind lift point |
| 4WD | Standard |
| Weight | 3,900 – 4,000 lbs (approx.) |
| Wheelbase | 73.0 inches |
| Top Speed | ~18.5 mph (forward) |
| Loader Compatibility | Yes, with 400CX or H180 loaders |
| Cab Option | Factory cab with HVAC available |
🧰 Maintenance Tips for Long-Term Reliability
| Task | Interval |
|---|---|
| Engine Oil & Filter | Every 100 hours or annually |
| Hydraulic Fluid & Filter | Every 400 hours |
| Fuel Filter | Every 200 hours or as needed |
| Air Filter | Check every 50 hours, replace at 200 hrs |
| Radiator Cleaning | Every 100 hours or more in dusty use |
| Front Axle Oil | Every 300 hours |
| Grease Fittings | Every 10–20 hours of operation |
Tips:
- Always use John Deere Plus-50 II oil and Hy-Gard transmission fluid
- Replace OEM filters to prevent premature wear
- Monitor regen cycles if equipped with emissions components
🛠️ FAQs: John Deere 4720 Troubleshooting & Ownership
✅ Is the 4720 tractor Tier 4 compliant?
No. The 4720 predates Tier 4 Final standards, making it popular for buyers avoiding DPF/DEF systems.
✅ What attachments are compatible?
- Front-end loaders (400CX, H180)
- Backhoes (485A)
- Snow blowers, rotary tillers, box blades, bush hogs, and more via Category 1 or 2 3-point hitch.
✅ Can it handle large implements?
With 56 PTO hp and nearly 2,500 lb hitch lift, it handles 5–7 ft implements like mowers, tillers, and post-hole diggers easily.
✅ Why does my hydrostatic transmission whine?
That’s normal to some degree but excess noise signals air in lines, low fluid, or pump wear.
✅ How many hours is the 4720 good for?
With proper care, many owners report 4,000–6,000+ hours before major repairs.
⚠️ Known Issues Recap
| Problem | Common Cause | Fix |
|---|---|---|
| Hard starting | Battery, fuel solenoid | Check/replace both |
| PTO won’t engage | Switch, seat sensor | Bypass or replace |
| Electrical failures | Grounds, fuse box corrosion | Clean and seal |
| Overheating | Radiator clog or thermostat | Clean and test |
| HST jerking/slipping | Low oil, clutch wear | Refill or service transmission |
✅ Final Verdict: Is the John Deere 4720 a Good Tractor?
The John Deere 4720 is one of the best pre-emissions compact utility tractors ever built. It blends power, versatility, and comfort in a way few modern units match. Its non-DPF turbo diesel engine is robust and reliable, and parts availability remains strong.
As long as you keep up with routine service, address electrical quirks, and monitor the hydrostatic system, the 4720 can deliver decades of performance.
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I’m David man behind Lawn Mowerly; I’ve been dealing with lawnmowers and Tractors with my father since I was a kid. I know every make and model and what each one is capable of and love helping people find the perfect equipment for their needs.