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Massey Ferguson 230, 235, 240, 245, 250 - Manual steering gear and control valve

MF 230, 235, 240, 245, 250 Tractors Repair Operations

MF 230, 235, 245 tractors

MF 230, 235, 245 tractors - The steering gear assembly includes the power steering control valve, power assist piston and cylinder as well as steering shaft, rack and pitman shafts necessary for manual steering.

Remove and reinstall - To remove the power steering gear, first remove the battery and the steering wheel. Disconnect the oil pressure line at gage and tachometer cable at both ends, then remove the tachometer cable and cable housing. Mark all wires to facilitate reassembly, then disconnect all wires from instrument panel gages. Remove lights from panel gages and disconnect fuel shut-off from injection pump (diesel models). Remove the complete instrument panel with gages. Disconnect wires from starter switch and light switch, then unbolt and remove the rear hood assembly with starter and light switches installed. Disconnect linkage from both ends of the throttle cross shaft, then slide shaft from left side of tractor. Remove the complete air cleaner assembly and the battery platform. Clean the area thoroughly before disconnecting any power steering lines. Disconnect hydraulic lines and plug all openings to prevent entrance of dirt. Disconnect drag links from both pitman arms, remove the six retaining screws, then lift the steering gear from Massey Ferguson 230, 235, 245 tractor. Reinstall reversing the removal procedure. Be careful to connect wires to instruments correctly. Bleed the hydraulic system after all lines are connected. Be sure that pump is not allowed to operate without fluid.

Overhaul - To overhaul the removed unit, unbolt right side pinion housing and remove pitman shaft, housing and related parts. Turn unit over and drain oil from housing, then unbolt and remove the left pinion housing, pitman shaft and related parts. Mark control valve head, valve body, bearing housing and steering gear housing before disassembly to facilitate correct reassembly. Unbolt and remove control valve housing, head, bearing housing, steering shaft and rack unit. Unscrew piston and rack as a unit from shaft, then remove bearing housing. To disassemble control valve and steering shaft, use caution and carefully identify parts as they are removed. Some parts used may be slightly different. Remove top snap ring, washer and seal. Remove second snap ring and lift parts from shaft. Remove valve body from valve spool. Be careful not to lose or damage parts of plungers. Remove return fitting and adapter, being careful not to lose check ball. Pitman shafts and related parts can be withdrawn from housings after snap ring is removed. Inspect all parts for wear or damage and renew if necessary. Install new seal in head with lip of seal towards valve body and end of seal flush with edge of housing bore. Press new bushings into housings until flush to 0.8 mm (1/32 inch) below flush with outer edge of bore. Lips of seals should face inward. Some MF 230, 235, 245 models use a washer and snap ring to retain seals in housings. When renewing O-rings and seals in bearing housing, be sure O-rings are installed under the seal rings. Assemble lower snap ring, washers, bearings and spool onto steering shaft. Install shims until upper snap ring will just fit into groove in shaft. End play of spool on shaft must be less than 0.076 mm (0.003 inch). Remove upper snap ring, washers and thrust bearing from shaft after correct end play is obtained. Install check ball and fitting in valve body.

Temporarily thread piston and rack onto shaft. Install lower snap ring, lower thrust bearing and valve spool onto shaft. The groove inside valve spool must be towards top (steering wheel) end of shaft. Install centering springs and plungers, then carefully install valve body. Install upper thrust bearing, shims, washers and snap ring. The centering springs will make it difficult to install the snap ring into its groove, however, a 25x110 mm (1x4-1/4 inch) piece of pipe to push snap ring into place. Install washer with chamfer down over snap ring. Install top snap ring. Remove piston and rack from shaft. Install bearing housing over shaft being sure that O-rings at (R) are aligned with corresponding holes in control valve body. Install piston and rack onto shaft. Install head over shaft aligning scribe marks made prior to disassembly. Install control valve, steering shaft, piston and rack assembly into the steering gear housing. Be careful not to damage piston seal ring, and be sure to maintain alignment of housings. Secure in position with retaining screws. Assemble parts onto pitman shafts before installing shafts into pinion housing. Adjust thickness of shims as necessary to remove all end play from bearing. Turn the installed steering shaft until the rack is at bottom of travel, position the steering gear housing as normally installed on the tractor and install the left pitman shaft and housing assembly. The flat identification boss on left housing should be down when installed. The marked third tooth on left pinion should be aligned with the center valley of the rack. Install retaining screws, then turn steering shaft until rack is all the way up in housing. Align the first tooth on right pinion with first valley on left pinion. The identification boss on right housing should be toward front as installed on Massey Ferguson 230, 235, 245 tractor. After correct alignment is obtained, the right side pinion housing can be temporarily removed (while maintaining correct alignment) and housing filled through opening to capacity with Permtran Oil or equivalent. Install the right pinion housing and right pitman shaft after filling with oil. Adjust gear backlash as follows: Rotate the right pinion housing clockwise to end of bolt slots and temporarily tighten retaining screw. Rotate the left pinion housing counterclockwise until all backlash is eliminated, then tighten the four housing retaining screws. Rotate the right pinion housing counterclockwise until all backlash is removed from the right pitman shaft, then tighten the four retaining screws. Check for correct assembly by locating the center (straight ahead) position of the steering shaft. With steering shaft straight ahead, the blank splines on both pitman shafts should be vertical. The small nat mounting boss at rear of steering gear housing will also be vertical when installed on tractor.

Steering gear and control valve (MF 240, 250)

A recirculating ball type steering unit is used on Massey Ferguson 240, 250 tractors. Twin pitman arms transmit steering wheel movement to front wheels. The power steering control valve is mounted on the steering column tube. The valve is manually actuated by movement of the steering wheel to direct pressurized oil to two double-acting cylinders attached to spindle steering arms.

Remove and reinstall steering gear - To remove steering gear box, first remove steering wheel hub cap and nut. Remove steering wheel using a suitable puller. Disconnect battery cables and remove battery. Disconnect fuse box mounting panel. Tag and disconnect electrical wiring between tractor wiring harness and instrument harness. Remove lower instrument panel. Disconnect tachometer cable. Disconnect hand throttle lever from throttle linkage. Remove instrument panel mounting cap screws, then lift instrument panel off the steering column. Remove pitman arms using a suitable puller. Disconnect hydraulic lines from power steering valve. Remove cap screws attaching steering box to the side support brackets and to the transmission housing. Shtft transmission into neutral, then remove steering gear box with shift levers from Massey Ferguson 240, 250 tractor. To reinstall steering gear box, reverse the removal procedure while noting the following special instructions: Apply gasket maker compound to mounting surface of gear box. Tighten pitman arm retaining nuts to 340 Nm (250 ft.-lbs.) torque. Tighten steering wheel retaining nut to 47 Nm (35 ft.-lbs) torque.

Overhaul steering gear - Disassemble the removed unit, first disconnect and remove control valve from steering column. Remove plug from steering column and drain oil from housing. Unbolt and remove cover plate from housing. Withdraw the secondary pitman shaft. Remove retainer plate and shims. Unbolt and remove steering column assembly from housing. Remove primary pitman shaft and steel ball. Unscrew ball nut from steering shaft. Remove set screw securing housing retainer. Slide retainer and felt seal away from steering shaft housing, then remove snap ring from its groove. Remove nut and washer from shaft. Remove acijustable race nut, then lift housing from shaft. Note that 12 steel balls are contained in the housing. Withdraw steering shaft from outer column. Remove felt seal and retainer from column tube. Inspect all parts for wear or damage and renew if necessary. Replacement pitman arm bushings are semi-finished and inside diameter must be reamed to correct size after installation. Attach cover plate to housing, then ream each pair of bushings using special tool number MF19A reamer. Thoroughly clean housing after reaming to remove all metal particles. Reassemble, position retainer with a new felt seal on column tube. Insert steering shaft into tube. Assemble the 12 steel balls in outer race of housing using grease to hold balls in place, then carefully slide housing over steering shaft.

Install adjustable race nut and tighten to 14 Nm (10 ft-lbs.) torque, then loosen nut one flat. Install washer and locknut to secure adjustable race nut adjustment. Thread ball nut onto steering shaft while assembling the 28 steel balls into the nut. Turn the ball nut to top of steering shaft threads. Assemble primary pitman shaft into housing. Use grease to hold steel ball in place in pitman shaft. Insert steering shaft into housing and rotate pitman shaft and ball nut until steel ball is seated in the ball nut. Note that ball transfer tube on ball nut must be facing away from pitman shaft. Install and tighten cap screws attaching steering column tube to housing. Install retainer plate with extra shims to ensure ball nut free play. Turn steering shaft until ball nut is centered on shaft threads, then remove shims as necessary until there is no end play in ball nul but nut still rotates freely. Install secondary pitman shaft and cover plate. Refill housing with SAE 90 gear oil. Install snap ring into groove of column tube. Secure retainer to bearing housing with the set screw. Install control valve with new O-rings and tighten mounting cap screws to 22-25 Nm (16-18 ft-lbs.) torque. Reinstall steering box. Adjust power steering control valve linkage.

Remove and reinstall control valve - Remove control valve, first remove battery cover panel and disconnect battery cables. Unbolt and remove instrument panel lower cover. Disconnect hydraulic lines and control linkage from valve. Remove mounting cap screws and remove valve from steering column. Reinstall valve, reverse the removal procedure. Be sure to renew O-rings in steering column oil ports. Tighten valve mounting cap screws to 22-25 Nm (16-18 ft-lbs.) torque. Adjust control valve linkage as follows: Remove pin connecting control linkage to valve spool. Turn steering wheel to the right to remove all free play in steering box without turnung the front wheels. Adjust length of linkage until retaining pin can be freely remserted in spool, then remove pin and increase length of control link by unscrewing rod one full turn. Reattach linkage to valve spool. Start engine and check for full power assistance in both directions.

Overhaul control valve - Disassemble removed unit, remove snap ring, washers and felt seal. Remove end cover mounting screws, then withdraw valve spool assembly with end cover and yoke. Unscrew yoke from spool and separate springs and washers from spool. Tap bypass valve piston, ball and spring from valve body. Remove relief valve spring and ball. Inspect all parts for wear or damage and renew if necessary. Renew all O-rings when reassembling. Valve spool and body are available only as a matched set. To reassemble valve, reverse the disassembly procedure. Lubricate all parts with oil during assembly. Reinstall valve and adjust linkage.