Issued by Tigercat under document number 45701AENG, this 686-page Tigercat 234B service manual PDF is the OEM's own book for the 234B loader. Electrical schematics trace the MD3 computer control circuits, while pilot hydraulic circuit diagrams and the load sense chapter show how oil is routed to each function. Engine anti-stall, the self-propelled drive, cooling with its variable pitch fan, and the boom, swing, grapple and live heel circuits each get their own chapter, several ending in an electronic adjustment procedure. When you change the hydraulic return filter, note that its bypass valve cracks at 1.7 bar (25 psi) and the restriction switch activates at 1.4 bar (20 psi). Your work may be the next entry on the preventive maintenance schedule, or a sample drawn under the oil sampling program. Bookmarked chapters and searchable text reach those values fast. The filter service then matches Tigercat's own numbers.
What's Inside This Tigercat 234B Manual
| System | Pages | Key Topics |
|---|---|---|
| Introduction | 5 | |
| Machine Identification and Serial Numbers | 6 | Machine Serial Number Plate, Upper Frame, Engine Identification Label, Engine Serial Number |
| Non-Approved Field Product Changes | 7 | Unauthorized Attachment |
| Regulatory Information | 8 | Telematics Module, Iqan-G11, Inmarsat Modem, Iridium Modem |
| Safety | 9-40 | Safety Precautions, Fire Prevention |
| Controls and Operation | 41-156 | Cab Controls, MD3 Computer |
| Lubrication and Maintenance | 157-212 | Preventive Maintenance Schedule, Oil Sampling Program |
| Hydraulic System/ Load Sense Control | 213-236 | Hydraulic System Operation, Load Sensing |
| Pilot System | 237-254 | Pilot System Components, Pilot Hydraulic Circuit Diagrams |
| Electrical and Computers | 255-374 | MD3 Computer Electronic Control, Electrical Schematics |
| Engine and Anti Stall | 375-388 | Engine Start Circuit, Anti-Stall |
| Self Propelled | 389-446 | Circuit Components, Electronic Adjustment Procedure |
| Cooling System | 447-460 | Cooling System Description, Variable Pitch Fan |
| Boom Functions | 461-520 | Boom System Components, Electronic Adjustment Procedure |
| Swing | 521-554 | Swing Pump, Electronic Adjustment Procedure |
| Stabilizers | 555-566 | Stabilizer Circuit Components, Stabilizer Circuit Description |
| Grapple | 567-616 | Grapple System Components, Electronic Adjustment Procedure |
| Live Heel | 617-644 | Live Heel Components, Electronic Adjustment Procedure |
| Delimber/Slasher and Circle Saw | 645-686 | Delimber/Slasher Circuit Components, Electronic Adjustment Procedure |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Hydraulic oil return filter bypass valve cracking pressure | 1.7 bar (25 psi) | p. 174 |
| Hydraulic oil return filter restriction pressure switch activation | 1.4 bar (20 psi) | p. 174 |
| Hydraulic pilot filter bypass valve cracking pressure | 50 psi | p. 176 |
| Swing pump charge pressure filter bypass valve cracking pressure | 50 psi | p. 177 |
| Main Relief Pressure | 500 psi + 1/2 turn in | p. 205 |
| Margin Pressure ('PX' - 'PL') | 375 psi | p. 205 |
| Lower bearing grease interval | every 250 hrs | p. 526 |
| Swing bearing bolts torque | 400-450 lbf-ft (540-610 Nm) | p. 206 |
| Swing bearing wear limit | 2.7mm (0.105") | p. 552 |
| Main pump neutral output pressure | 500 psi | p. 216 |
| Pilot system pressure | 35 bar (508 psi) | p. 219 |
| Counterbalance cartridge relief pressure | 1000 psi | p. 559 |
Tigercat 234B Common Problems This Manual Covers
Tigercat 234B load sense hydraulics slow and weak across several functions under load
Check margin pressure at the 'PX' and 'PL' test ports on the main pump controller against 26 bar/375 psi (page 234). Then verify pump POR at 288 Bar/4175 psi and main relief at 330 Bar/4785 psi following page 236. Keep everyone clear of the grapple; a slight touch of the controls can rotate the upper frame (page 236). Do not change any pressure setting without Tigercat authorized instruction (page 22).
Manual Section: Hydraulic System Troubleshooting p. 236Hydraulic oil return filter restriction pressure switch activating and filter bypass valve opening
Replace the hydraulic oil return filter following page 174. The restriction pressure switch activates at 1.4 bar (20 psi) and the bypass valve cracks at 1.7 bar (25 psi). Stop the engine and relieve all hydraulic pressure before opening any line or housing (page 24). Top off the reservoir, which holds 66 U.S. gallons (250 L) per page 215.
Manual Section: Lubrication and Maintenance p. 174Swing function weak in one direction or harsh swing acceleration and deceleration
Park on flat level ground, bring hydraulic oil to operating temperature, and check the swing relief valves following page 549: swing pump POR 290 bar/4200 psi, CW and CCW reliefs 310 bar/4500 psi, charge relief 25 bar/360 psi. Keep everyone away from the grapple (page 549). Swing acceleration and deceleration rates are set at the lens plate timing adjustment screw on page 550; get Tigercat authorized instruction before changing any setting (page 22).
Manual Section: Swing System Troubleshooting p. 549Swing bearing worn with excess backlash and loose outer race mounting bolts
Measure swing bearing wear against the 2.7 mm (0.105 in) wear limit following page 552. Check swing bearing backlash against 0.017 in to 0.026 in on page 554. Torque the outer race bolts to 450 lbs. ft. and the swing bearing mounting bolts to 400-450 lbs. ft. When servicing the swing drive gearbox, refill with 75W-90 or 80W-140 gear oil (page 170).
Manual Section: Swing System Troubleshooting p. 552Stabilizer up or down function weak, cylinder will not develop port relief pressure
Check stabilizer port reliefs following page 565: up 138 bar/2000 psi, down 207 bar/3000 psi. You may need to lower all stabilizers to the end of stroke to build pressure, so watch machine stability. Counterbalance cartridge relief is 1000 psi (page 559). Before pulling a counterbalance or check cartridge, raise the stabilizer overcenter and stop the engine; never remove them with the stabilizers on the ground (page 22).
Manual Section: Stabilizer System Troubleshooting p. 565Grapple weak gripping force with open or close feed reducer pressure below setting
Park on flat level ground with hydraulic oil at operating temperature. Check the grapple open and close feed reducers against 172 bar/2500 psi and pump POR at 288 bar/4175 psi following page 609. Keep everyone clear of the grapple. Never disconnect a grapple valve solenoid with the engine running (page 568); it can cause sudden grapple arm movement.
Manual Section: Grapple System Troubleshooting p. 609Frequently Asked Questions
How do I clear a DEF or aftertreatment fault on a Tigercat 234B?
To correct a DEF quality problem, clean the area around the DEF tank, then drain and refill the tank with clean DEF that meets ISO 22241 specifications. Additional messages from the Denox Module may be displayed, and you should refer to the engine manuals for specific code information. Refer to page 125 for the full procedure and warnings regarding DEF quality. p. 112
What are the hydraulic pressure test points and specifications for the main pump on a Tigercat 234B?
The main pump POR valve is set to 262 bar (3800 psi), and the margin pressure is set to 26 bar (375 psi). These pressures are measured at the 'PL' test port located on the inlet section of the main control valve. Refer to page 98 for the detailed pressure setting procedure. p. 98
What is the correct torque for the trailer mounting studs on a Tigercat 234B?
The trailer mounting studs (1"-8 UNC G5) should be torqued to 443-489 lbf-ft (601-663 Nm). Refer to the torque chart on page 68 for additional mounting hardware specifications. p. 68
How often should the swing gearbox lower bearing be lubricated?
The swing gearbox lower bearing should be lubricated every 250 hours. Use a hand grease gun to add 5 shots of lithium-based EP2 grease to each side of the gearbox. p. 165
What is the procedure for checking the swing bearing wear on a Tigercat 234B?
The swing bearing is considered worn when the total play at any one location is 2.7mm (0.105") or greater. Use a dial indicator mounted to the bearing mounting flange to measure the play while moving the boom between position 1 and position 2 as shown on page 138. p. 138
How will I receive this Tigercat 234B Service Manual?
Immediate download of the complete 686-page searchable Service Manual. Access it on any device, from a laptop at your desk to a phone in the field.
Is this Tigercat 234B manual print-friendly?
Yes. Printing works from any reader and any printer, for your own shop use.
