Within the hour you could have gauges on the drive pump test ports, working from this 658-page Tigercat 620E service manual PDF (OEM ID 42837AENG), which covers all four E-series skidders from the 620E through the 635E. Hydraulic schematics trace the drive, steering, grapple, arch, winch and dozer circuits, and wiring diagrams lay out the computer control modules and engine start circuit so you can chase a dead signal connector by connector. Drive is the biggest chapter in the book, running from hydrostatic setup through pump pressure checks, and fault code listings plus scheduled maintenance tables cover the diagnostic side. Set high pressure relief at 6090 psi (420 bar) and hold charge relief between 350 and 375 psi (24 to 26 bar). Every hour parked at the landing is wood left in the bush. Your copy is bookmarked and text-searchable, and it prints cleanly, so the drive chapter can go to the bench and soak up all the oil it wants.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Introduction | 2-5 | Operator's Manual, Service Manual, Parts Catalog, Serial Numbers, Preventive Maintenance Schedule |
| Machine Identification and Serial Numbers | 6 | Machine Serial Number Plate, Front Chassis, Rear Chassis |
| S.A.E. Standards (ROPS, FOPS, Ops) | 7 | ROPS Structure, FOPS Structure, OPS Structure |
| Non-Approved Field Product Changes | 8 | |
| Regulatory Information | 9 | Telematics Module, Iqan-G11, Radio |
| Warranty–Epa | 10-11 | Emission Control Information Label, Fuel Injection System, Air Induction System, Positive Crankcase Ventilation System, Exhaust After Treatment Devices |
| Ec Declaration 620e 625e 630e | 12-14 | Self Propelled Forestry Machine, Wheeled Grapple Skidder, Articulated Frame, Grapple System, Tree-Length Harvesting System |
| Safety | 15-52 | Articulation Lock, Battery Disconnect Switch, Battery Safety, Cab Exits, Cab Safety Cable, Cab Support Brace, Diesel Exhaust Fluid, Emergency Cab Exits |
| Controls and Operation | 53-180 | Cab Controls, Computer Control System |
| Lubrication and Maintenance | 181-290 | Tigercat Fluid Analysis Program, Scheduled Maintenance |
| Electrical and Computers | 291-344 | Computer Control System, Computer Modules |
| Engine Start and Stop | 345-354 | Engine Start Circuit |
| Drive | 355-492 | Hydrostatic Setup Procedure, Drive Pump Pressure Checks |
| Brakes and Differential Locks | 493-514 | Accumulator, Parking Brake Caliper |
| Cooling System | 515-530 | Cooler Package, Variable Pitch Fan |
| Steering and Centre Joint | 531-554 | Steering Control Valve, Centre Joint |
| Grapple, Arch and Boom | 555-600 | Control Valve, Grapple Rotate Assembly |
| Winch | 601-644 | Allied Winch, Carco Winch |
| Dozer Blade | 645-658 | Dozer Circuit Description |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Slew bearing cap screw torque | 386 N-m (285 lbf-ft) | p. 488 |
| Hydraulic oil double element filter bypass valve pressure | 25 psi (1.7 bar) | p. 208 |
| Charge pressure filter bypass valve pressure | 50 psi (3.5 bar) | p. 210 |
| Bearing heating temperature | 250°F (121°C) | p. 475 |
| Bearing feeler gauge clearance | 0.001-0.002 in (.025-.051 mm) | p. 475 |
| B17-B20 planet gear bearing recess | 9.5 mm (0.375 in) | p. 481 |
| Axle shaft endplay | 0.090 to 0.110 in (2.29 to 2.80 mm) | p. 483 |
| Wheel end bolt torque | 300 lbf-in (407 N-m) | p. 483 |
| Input gear cover bolt torque | 75 Nm (55 ft-lbf) | p. 490 |
| Bogie axle shaft end play | 0.090-0.110 in (2.29-2.79 mm) | p. 483 |
| Engine High Idle (Tier 2) | 2100 rpm | p. 389 |
| Engine High Idle (Tier 4f) | 2200 rpm | p. 389 |
