Part of the John Deere Repair Manuals.
This 272-page John Deere 1520 Technical Manual (OEM #TM-1012) walks you through every system on the tractor, from the closed-center hydraulic circuit to the Hi-Lo shift power train. You get full wiring diagrams for the charging, starting, and ignition circuits, hydraulic schematics covering the rockshaft and steering systems, and a dedicated troubleshooting section for diagnosing malfunctions before you start pulling parts. Torque tables and clearance specs run throughout, so you're working from real numbers, not shop-manual guesswork. Piston to liner clearance runs 0.0010 to 0.0034 in. on gasoline engines and 0.0084 to 0.0108 in. on diesel; float clearance on the carburetor sits at 1/4 in. from the gasket surface. Stop tearing into the front axle or clutch blind. This PDF is bookmarked and searchable, so you can jump straight from the table of contents to the exact page your 1520 needs.
What's Inside This John Deere 1520 Manual
| System | Pages | Key Topics |
|---|---|---|
| Technical Manual | 1-4 | - |
| General | 5-24 | Specifications, Predelivery, Delivery, And After-Sale Services, Tune-Up, Lubrication, Separation |
| Engine | 25-70 | General Information and Diagnosis, Cylinder Head, Valves and Camshaft, Cylinder Block, Liners, Pistons, And Rods, Crankshaft |
| Fuel Systems | 71-86 | Diagnosing Malfunctions, Diesel Fuel System, Gasoline Fuel System |
| Electrical System | 87-122 | Information and Diagrams, Charging Circuit, Starting Circuit, Ignition Circuit, Lighting and Accessory Circuits |
| Power Train | 123-190 | Clutches, Hi-Lo Shift Unit, Reverser, Collar Shift Transmission, Differential, Final Drive, Continuous Running and Transmission-Driven PTO, Independent PTO |
| Steering and Brakes | 191-192 | General Information |
| Hydraulic System | 193-268 | General Information, Diagnosis, And Tests, Miscellaneous Hydraulic Components, Hydraulic Pumps, Steering Systems, Hydraulic Brakes, Rockshaft System |
| Miscellaneous | 269-272 | Front Axle (Removal, Repair, Installation, Specifications, Torques for Hardware, Special Tools) |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Hydraulic System Type | Closed center, constant pressure | p. 6 |
| Clutch | Single or dual stage, spring-loaded, dry | p. 5 |
| Clutch Disk Thickness (with facing) | 0.0593 to 0.0643 in. | p. 188 |
| Crankcase Oil Capacity (with filter) | 6 qts. | p. 5 |
| Fuel Tank Capacity | 19-1/2 gals. | p. 5 |
| Gasoline | ||
| Piston to Liner Clearance (top) - Gasoline | 0.0010 to 0.0034 in. | p. 46 |
| Carburetor Float Setting (gasket to float edge) | 1/4 in. | p. 86 |
| Maximum PTO Horsepower (Gasoline) | 47.86 hp | p. 5 |
| Diesel | ||
| Piston to Liner Clearance (top) - Diesel | 0.0084 to 0.0108 in. | p. 46 |
John Deere 1520 Common Problems This Manual Covers
John Deere 1520 engine dieseling and backfiring during cold starts or after storage
Check the ignition timing and carburetor adjustment first. Verify the carburetor float sits 1/4 in. from the gasket surface with the carburetor inverted, per the fuel system specs on page 86. Inspect the breaker points for pitting and confirm spark plug gap is correct before condemning the block.
Manual Section: Fuel System Diagnosing Malfunctions p. 86Piston sleeve corrosion and pitting inside the cylinder liners after roughly 2,500 hours
Drain the cooling system and inspect the cylinder liners for pitting consistent with coolant intrusion. Measure piston-to-liner clearance at the top of the skirt: gasoline engines should read 0.0010 to 0.0034 in., diesel engines 0.0084 to 0.0108 in., per page 46. Replace liners and O-rings if clearance or corrosion exceeds tolerance.
Manual Section: Engine Cylinder Block, Liners, Pistons, and Rods p. 463-point hydraulic lift not holding position or lifting sluggishly under load
Check the main hydraulic pump standby pressure with a gauge; it should hold at 2250 psi per page 6. Inspect the return valve for sticking open and check the rockshaft piston O-ring for leakage, both listed as causes on the rockshaft diagnosis chart on page 233. Adjust the negative stop screw and cam follower screw if lift response stays slow.
Manual Section: Rockshaft System Diagnosis p. 233Gear shift lever keeps spinning for nearly 20 seconds when moving between gears
Inspect the clutch for incomplete disengagement, the most likely cause of prolonged gear spin. Measure disc facing thickness and replace if it falls outside 0.0593 to 0.0643 in. per page 188. Check clutch pedal free travel and adjust the linkage so the throw-out bearing fully releases before you try to shift.
Manual Section: Clutches Diagnosing Malfunctions p. 1883-point hydraulic system acts inconsistent when running the bucket and rear blade together
Tee a gauge into the pump supply line and check standby pressure; it should read 2250 psi per page 6. If pressure drops when a second function engages, inspect the pressure control valve and transmission pump, both flagged on the rockshaft diagnosis chart on page 233. Confirm hose routing against the schematic.
Manual Section: Hydraulic System General Information, Diagnosis, and TestsFrequently Asked Questions
What are the torque specifications for the main bearing cap screws on the John Deere 1520?
The main bearing cap screws on the John Deere 1520 should be tightened to 85 ft-lbs. This is a critical specification for engine assembly. p. 52
How can milky hydraulic fluid be fixed on a John Deere 1520?
Milky hydraulic fluid, often caused by water in the hydraulic system or wrong oil viscosity, can be fixed by draining the old fluid and refilling the system with proper oil. p. 199
How do I fix a load control shaft leak on a John Deere 1520?
To fix a load control shaft leak, inspect the bushings, sealing ring, and O-ring for wear or damage. If replacement is necessary, install a new bushing by chilling it and driving it into the case with a JD248 driver, ensuring the sealing ring groove faces outward. p. 238
What are the replacement specifications for piston liners on the John Deere 1520?
If a cylinder liner is replaced on the John Deere 1520, the piston and rings for that specific cylinder should also be replaced with new parts to ensure proper fit and function. p. 43
How quickly can I access this John Deere 1520 manual after buying?
Instant PDF download. You get the full 272-page searchable Technical Manual immediately after payment. Open it on your laptop, tablet, or phone right in the shop.
Can I print specific sections of this John Deere 1520 Technical Manual?
Absolutely. No DRM or copy protection. Print the whole manual or just the pages you need. Any home or office printer works.
Does this John Deere 1520 manual include wiring diagrams?
Yes. You'll find an electrical wiring diagram covering the main wiring layout.
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