Two manuals, one download. Fiat printed the Series 66 workshop manual as a 1987 revision. It reprints only the pages that changed and keeps the original page numbers, so an owner could swap the loose leaves into the book he already had. That older book is the 466/566/666/766 workshop manual, and the revision refers back to it constantly. Both are included here, 491 pages together.
That is why a section in the Series 66 manual can start partway in, at page 9 or later: the earlier pages sit in the base manual, in the same section, under the same numbers. Where both books print the same page number, the Series 66 revision is the newer one and supersedes it.
Between them you get electrical wiring diagrams, exploded views of the transmission and splitter, injection pump timing with Bosch VE and C.A.V. DPS calibration data, Valeo and Luk clutch overhauls, bevel drive and no-spin differential rebuilds, front axle king pin and wheel bearing adjustments, and the hydraulic lift troubleshooting chart.
Coverage runs from the 45-66 to the 80-66, including DT, V and F variants, plus the 466 to 766 models in the base book. Both PDFs are searchable, so you can type the spec you need instead of leafing through both books.
What's Inside This Fiat 45-66 to 80-66 Series Manual
| System | Pages | Key Topics |
|---|---|---|
| MANUAL 1 of 2 · Series 66 Revision · Print No. 603.54.228.02 · 239 pages | ||
| General | 4-7 | Contents, general instructions, safety precautions |
| Specifications: 55-66 to 80-66 | 9-15 | Engine, power train, hydraulic lift, capacities, main dimensions, tractor 65-66 data |
| Engine: Fuel System | 16-19 | Bosch VE and C.A.V. DPS injection pump removal, installation and timing |
| Front Wheel Drive: Live Front Axle (466DT-766DT) | 20-25 | Bevel pinion bearing adjustment, differential overhaul, no-spin differential |
| Front Wheel Drive: Sections | 26-27 | Front wheel drive sections, king pin bearing adjustment |
| Hydraulic Lift Unit | 28-31 | Draught control adjustment, maximum lift arm travel, valve checks |
| Model 45-66: General and Specifications | 32-45 | Contents, engine, power train, capacities, torque data |
| Model 45-66: Engine | 46-49 | C.A.V. DPS injection pump calibration data, performance data |
| Power Train | 50-91 | Valeo and Luk clutch overhaul, transmission and splitter, bevel drive and differential, brakes, final drives, power take-off |
| Front Axle and Steering | 92-97 | Front axle, power steering, hydraulic cylinder overhaul, relief valve calibration |
| Front Wheel Drive: Front Axle (45-66) | 98-103 | Removal, bevel pinion bearing shim, king pin and wheel bearing adjustment |
| Hydraulic Lift Unit | 104-119 | Lift and lift pump overhaul, position and draught control, remote control valves, trailer brake valve |
| Electrical System | 120-123 | Wiring diagram, charging system, starter, switches, instruments |
| Service Tools | 124-127 | Tool numbers by section, steering hydraulic test equipment |
| V and F Series Supplement | 130-189 | 45-66V, 55-66V, 55-66F, 60-66F, 70-66F, 80-66F: specifications, power train, front axle, front wheel drive, hydraulics, electrical |
| LP Series Supplement | 192-237 | 55-66LP, 60-66LP, 70-66LP: specifications, power train, front wheel drive, hydraulics, electrical |
| MANUAL 2 of 2 · Base Manual 466 / 566 / 666 / 766 · Print No. 603.54.228.00 · 252 pages | ||
| General | 3-10 | Contents, general instructions, safety precautions |
| Specifications | 11-24 | Engine, power train, front axle, hydraulic lift, electrical system, capacities |
| Engine | 25-74 | Engine block, cylinder head and sleeves, crank gear, valve gear, lubrication, cooling, fuel system |
| Power Train | 75-136 | Clutch, transmission and splitter, creeper and reverser, bevel drive and differential, brakes, final drives, power take-off |
| Front Axle and Steering | 137-164 | Front axle, steering knuckle overhaul, manual steering box, power steering overhaul and bleeding |
| Front Wheel Drive: Front Axle | 165-182 | Removal, final drive and wheel hub, king pin bearing adjustment, wheel bearing adjustment, bevel drive and differential, no-spin differential |
| Hydraulic Lift Unit | 183-228 | Lift removal and overhaul, lift pump, implement attachment, remote control valves, trailer brake remote control valve |
| Electrical System | 229-246 | Wiring diagrams, charging system, starter, lighting, signals, fuse box, instruments |
| Service Tools | 247-250 | Tool numbers by section |
Page numbers above are PDF pages, not the numbers printed inside the book.
Fiat 45-66 to 80-66 Series Common Problems This Manual Covers
Fiat 55-66 hydraulic lift arms won't raise implement, lift pump sounds weak under load
Check the lift trouble shooting chart on page 6 before pulling the pump. Confirm oil level is correct and the remote control valve is fully seated, then crack the pressure line fitting to check for aeration. If flow is still low, pull the lift pump and check the relief valve spring and gear-to-housing clearance against the clearance specifications.
Manual Section: Hydraulic Lift Unit: Specifications and Data p. 6Engine cranks fine but won't start or misfires badly in cold, wet weather
Bleed the fuel system at the injection pump before chasing the injectors. Follow the injection pump timing procedure on page 16, checking pump-to-engine timing marks and delivery calibration data. Verify the fuel lift pump is passing fuel with no air in the line and check filter condition; a clogged element is the most common cause of hard starting.
Manual Section: Engine: Fuel System p. 16Clutch slips under heavy draft load even after pedal free-play adjustment
Recheck clutch pedal free travel first; if it's within spec and slip continues, pull the clutch cover and inspect the pressure plate fingers for uneven wear or a weak diaphragm spring. Measure friction disc thickness against wear limits and check the release bearing for drag. On Valeo units, verify release lever height is set evenly around the cover before reassembly.
Manual Section: Power Train: ClutchFront axle knuckle has excessive play, steering feels loose over rough ground
Jack the front axle and check king pin bearing endplay by hand before condemning the knuckle. Follow the king pin bearing adjustment procedure, torque the retaining nut to the value listed in the torque specifications, then recheck for play. Inspect the wheel hub bearings at the same time since worn hub bearings mimic king pin symptoms.
Manual Section: Front Wheel Drive: Live Front AxleTransmission grinds going into gear and driver can't find neutral cleanly
Verify clutch release is complete before blaming the gearbox; incomplete disengagement is the usual cause of gear clash. If the clutch checks out, drain the transmission and inspect the shift fork pads and synchronizer rings for wear. Check gear end float and shaft bearing preload against the technical specifications before reassembling the case.
Manual Section: Power Train: Transmission and SplitterFrequently Asked Questions
What are the torque specifications for the clutch to flywheel bolts on Fiat tractor?
The torque specification for the clutch to flywheel screws (C1, page 1) on the Fiat tractor is 25 Nm (2.6 kgm or 19 ft lb). These bolts have a thread size of M 8x1.25.
Is this Fiat 45-66 WORKSHOP MANUAL a digital download?
Instant PDF download (119 MB). You get the full 239-page searchable WORKSHOP MANUAL immediately after payment. Open it on your laptop, tablet, or phone right in the shop.
Can I print a copy of this Fiat 45-66 WORKSHOP MANUAL for the shop?
Yes, print as many copies as you want, and there are no restrictions. Many mechanics print the section they need and bring it to the shop floor.
Can I find wiring schematics in this Fiat 45-66 manual?
Included. The Fiat 45-66, 45-66 DT, 45-66 V, 45-66 DTV, 466, 566, 666, 756, 55-66, 55-66 DT, 55-66 V, 55-66 DTV, 55-66 F, 55-66 DTF, 55-66 LP, 55-66 DT LP, 60-66, 60-66 DT, 60-66 F, 60-66 DTF, 60-66 LP, 60-66 DT LP, 65-66, 65-66 DT, 70-66, 70-66 DT, 70-66 F, 70-66 DTF, 70-66 LP, 70-66 DT LP, 80-66, 80-66 DT, 80-66 F, 80-66 DTF WORKSHOP MANUAL covers complete wiring harness diagrams, electrical circuits, and connector pinouts.
