FE 35, 40, 55, EC 70 1 Service Manual FE 35, FE 40, FE 55 Electric Trimmers, EC 70 Electric Edger As the design concept of the FE 35 and FE 40 trimmers is almost identical, the descriptions and servicing procedures generally apply to both. Differences are described in detail. - The motors of the FE 55 trimmer and EC 70 edger are identical. The shafts and drives are different and are described separately. - Parts of the motor must neither be repaired nor modified in any way. You should make use of the illustrated parts lists while carrying out repair work. They show the installed positions of the individual components and assemblies. Microfilmed parts list are always more up to date than printed lists. Warning: When carrying out repairs to electric power tools it is essential to observe all relevant national safety regulations and ordinances. Important notes: - Every time you open the housing, clean the motor with a soft brush. Always use the mounting screws specified in the parts list - other screws must not be used. - Always use original STIHL replacement parts. - Original STIHL parts can be identified by the STIHL part number, the STIHl logo and the STIHL parts symbol ( The symbol may appear alone on small parts. A fault on the machine may have several causes. Consult the "Troubleshooting Chart" when tracing faults. Refer to the "Technical Information Bulletins" for engineering changes which have been introduced since publication of this service manual. Service manuals and technical information bulletins are intended exclusively for the use of STIHL servicing dealers and staff and must not be passed to third parties. The STIHL Special Tools manual lists all special servicing tools currently available from STIHL. STIHl FE 35, 40, 55, EC 70 2 CONTENTS 1. Specifications 3 3.6 Motor (FE 35, FE 40) 3.7 Carbon Brushes 1.1 Motor 3 1.2 Cutting Tool 4 1.3 Gearhead 4 Feed Mechanism 1.4 Special Accessories 5 (FE 40) 1.4.1 For User 5 1.5 Tightening Torques 5 2. Troubleshooting Chart (FE 35, FE 40) 3.8 3.9 2.1 Motor 6 2.2 Mowing Head 6 3. Electrical Circuit 7 3.2 Wiring Diagrams 3.3 (FE 35, FE 40) 3.4 3.5 (FE 55, EC 70) Gearhead (EC 70) 23 5.2.1 Disassembly 23 26 Adjusting Automatic 5.2.2 Assembly Feed Mechanism 5.3 Mowing Head / Motor Fanwheel 16 3.12 Adapter 16 3.13 Strain Relief Flap 16 4. Shaft 17 Line Feed Lever/ Activating Cord (FE 35) 18 Drive Shaft (FE 55, EC 70) 4.5 17 Drive Tube (FE 55, EC 70) 4.4 17 Connecting Tube / Loop Handle 9 19 Loop Handle (FE 55, EC 70) 10 5.2 3.11 9 Capacitor 21 (FE 35, FE 40) 4.3 Trigger / On/Off Switch / Bearing Housing 15 4.2 Power Cable (FE 55, EC 70) 14 20 21 (FE 55) Motor (FE 55, EC 70) 8 On/Off Switch 5.1 Mounting Plate 7 Power Cable (FE 35, FE 40) 13 Switch Unit of Automatic Cutting Tool Drive 15 4.1 3.1 5. (FE 40) 3.10 6 11 6. 28 Special Servicing Tools and Aids 30 6.1 Special Servicing Tools 30 6.2 Servicing Aids 31 FE 35, 40, 55, EC 70 1. 1.1 3 SPECIFICATIONS Motor Rating: Rated current: Voltage: Frequency: Maximum speed (without nylon line): Fuse: Insulation: Radio interference suppression: Type of enclosure: FE 35 FE 40 350 W 1.6 A 220 - 240 V 50 Hz 400 W 1.8 A 220 - 240 V 50 Hz 11,700 rpm 10A Class II VIDE 11,700 rpm 10A Class II VIDE Level "N" VIDE 0875 IP 20 to DIN 40050 Level "N" VIDE 0875 IP 20 to DIN 40050 FE 55/EC70 Rating: Rated current: Voltage: Frequency: Rated speed at width of cut, 350 mm (14 in) 1) Maximum speed (without nylon line): Fuse: Insulation: Radio interference suppression: 1) with cutting blade on EC 70 600 W 2.6 A 230 V 50 Hz 650 W 2.7 A 240 V 50 Hz 660 W 5.5 A 120 V 60 Hz 8,500 rpm 8,500 rpm 8,500 rpm 13,500 rpm 10A Class II VDE 13,500 rpm 10A Class II VIDE 13,500 rpm 15A Class II VDE Conforms to EEC directive 76/885 and DIN 57 875 Conforms to EEC directive 76/885 and DIN 57 875 Conforms to EEC directive 76/885 and DIN 57 875 FE 35, 40, 55, EC 70 1.2 Cutting Tool 4 FE 35 FE 40 FE 55 Mowing head: with two nylon lines with two nylon lines with two nylon lines Line diameter: 1.6 mm (0.065 in) 1.6 mm (0.065 in) 2.0 mm (0.080 in) Width of cut: 300 mm (12 in) 300 mm (12 in) 350 mm (14 in) Nylon line in spool: 10 m (33 ft) 10 m (33 ft) 2x3.75m(2x12.3ft) Line feed: semi-automatic fully automatic semi-automatic EC 70 Cutting blade 4133 713 4101 1.3 EC 70 Type: Gearhead Spiral-tooth bevel gear drive Gear ratio: 1.24 Bearings: Deep-groove ball bearings Lubrication: STIHL gear lubricant 0781 120 1117 FE 35, 40, 55, EC 70 1.4 5 Special Accessories 1.4.1 For User Spool with nylon line (10 m/33 ft) 4802 710 4300 1) Replacement nylon line (15.2 m/50 ft reel) 0000 930 2515 2) Replacement nylon line (spool) (FE 55) 4004 710 4304 4) Shoulder strap 4130 710 9000 2) Goggles 1.5 5) Tightening Torques Fastener Thread size For component Torque Nm lbf.ft Tapping screw IS-P4x19 Tapping screw Handle 1.2 0.9 1) IS-P4x19 Housing 1.1 0.8 1) Tapping screw IS-P4x35 Housing 1.2 0.9 1) Pan head screw M4x8 Mounting screw 1.8 1.3 1) Tapping screw IS-P6x19 Housing 5.5 4.0 2) 3) Tapping screw B3.5x9.5 Bearing housing 3.0 2.2 2) Spline screw IS-M5x18 Clamp on bearing housing 6.5 4. 8 2) Spline screw IS-M 6x20 Clamp screw in gearhead 7.5 5. 5 1) FE 35, FE 40 2) FE 55 3) EC 70 4) Not available in Europe 5) Standard equipment in some markets Remarks FE 35, 40, 55, EC 70 2. TROUBLESHOOTING CHART 2.1 Motor 6 Condition Cause Remedy Motor does not run Plug not in power outlet Connect plug to power outlet Carbon brushes worn (FE 35, FE 40) Fit new carbon brushes Switch unit faulty (FE 40) Replace switch unit Motor faulty Replace motor 2.2 Mowing Head Condition Cause Remedy Poor cutting performance Cutting line too short Readjust nylon line (FE 35, FE 55) Automatic feed mechanism not properly adjusted Adjust automatic feed mechanism correctly Does not cut Spool empty Fit new spool FE 35, FE 55: Line is not advanced when line feed lever is operated Spool empty Fit new spool Line sticking in spool Grip ends of line and pull firmly outward Activating cord broken Fit new activating cord FE 40: Line is not advanced even though feed process is audible, or no click is heard Ends of line not projecting from spool Pull ends of line about 10 cm (4") out of spool FE 40: Line is advanced too late or too often and cut off by line limiting blade on deflector Automatic feed mechanism not properly adjusted Adjust automatic feed mechanism correctly FE 35, 40, 55, EC 70 3. ELECTRICAL CIRCUIT 3.1 Wiring Diagrams Top: 1 = Power cable 2 = Switch with capacitor 3 = Wires with flat connectors 4 = Brush holder with carbon brush Bottom: 1 = Power cable 2 = Capacitor 1 1 3 = Switch 4 = Wires from motor 1) Capacitor not installed in all countries 7 Top: 1 = Power cable 2 = Switch 3 = Wires with right-angle connectors 4 = Brush holder with carbon brush 5 = Switch unit (electronic) 6 = Solenoid FE 35, 40, 55, EC 70 8 3.2 Power Cable (FE 35, FE 40) Top: Handle mounting screws Bottom: Removing on/off switch 1 = Screws Top: Cable protector Bottom: Correct position of power cable 1 = Cable protector 1 = Line feed lever 2 = Activating cord Caution: The power cable must positioned as shown so that it is not pinched when the handle is assembled. Make sure all wires are reconnected to their original terminals - see 3.1. - On FE 35, check that the activating ord is attached to line feed lever. Make sure that line feed lever is properly seated in the handle molding. - Tighten handle mounting screws to 1.2 Nm (0.9 Ibf.ft). Warning! Always unplug the unit from the power supply before performing any servicing or repair work. - Take the power cable out of the handle molding and slip the cable protector off the end of the cable. - Take out the handle mounting screws. Remove the two halves of the handle from the connecting tube. Installation is a reversal of the removal sequence. - Lift the on/off switch out of its seat, remove the screws and pull the wires out of the switch. Note: Pay special attention to the following points. - The cable protector must be properly engaged and the power cable correctly positioned in the handle molding. Warning! Always use only the handle molding mounting screws specified in the parts list. - On FE 35, check smooth action of line feed lever. FE 35, 40, 55, EC 70 3.3 On/Off Switch (FE 35, FE 40) 9 3.4 Power Cable (FE 55, EC 70) Top: Removing wires (FE 40) Top: Housing mounting screws Top: Correct position of on/off switch Bottom: On/off switch (FE 35) 1 = Capacitor Bottom: Removing on/off switch 1 = Connector tabs Bottom: Correct position of connecting wires - Disconnect the power cable from the on/off switch - see 3.2. - Use a thin pointed tool (e.g. scriber) to push back the clamping springs in the switch and then pull the wires out of the switch. Installation is a reversal of the removal sequence. Note: Fit wires by pushing them into the openings in the switch. - Take out housing mounting crews and remove the righthand housing molding. - Pull the on/off switch out of its seat in the left-hand housing molding and pull the two wires off the connector tabs. - Remove wires of power cable from the left-hand housing molding. Installation is a reversal of the removal sequence. - Fit on/off switch in its seat and check that it is properly located. - Position connecting wires correctly in housing molding. FE 35, 40, 55, EC 70 10 3.5 Cable protector Trigger / On/Off Switch / Capacitor (FE 55, EC 70) Top: Removing trigger Bottom: Connectors on switch 1 = On/off switch 2 = Push-on distributor 3 = Capacitor - Pull the push-on distributors off the connector tabs on the switch and remove the capacitor. Caution: The power cable must positioned as shown so that it is not pinched when the handle is assembled. Make sure both wires are reconnected to their original terminals - see 3.1. Installation is a reversal of the removal sequence. - The cable protector The cable protector must be properly engaged in the housing recess. Important: All wires must be reconnected to their original terminals - see 3.1. - Tighten housing molding mounting screws to 5.5 Nm (4.0 Ibf.ft). Warning! Always use only the housing molding mounting screws specified in the parts list. - Remove the right-hand housing molding - see 3.4. - Remove the trigger. - Pull the on/off switch out of its seat in the left-hand housing molding and disconnect all wires from the connector tabs and the push-on distributors. FE 35, 40, 55, EC 70 3.6 11 Motor (FE 35, FE 40) Top: 1 = Retaining lug 2 = Deflector shield Bottom: Clamp nut Top: Housing mounting screws Bottom: Activating cord on line feed lever (FS 35) - Use a screwdriver to lift the retaining lug on the deflector shield a little and then pull off the deflector shield. - Remove housing mounting screws and lift away the upper housing molding. - Unscrew the clamp nut from the housing. - Disconnect the activating cord from the adjusting lever. Top: Removing the solenoid 1 = Actuating pin 2 = Iron core Bottom: Removing the iron core - On FE 40, remove the solenoid from the mounting plate and pull the actuating pin out of the iron core at the same time. - Pull the iron core out of the solenoid and put solenoid to one side. FE 35, 40, 55, EC 70 12 Top: 1 = Adjusting lever 2 = Actuating pin Top: Connections on motor Bottom: Lifting motor out of housing Bottom: Housing slots - Pull the actuating pin out of the adjusting lever. - Lift the motor with mowing head out of the housing. - Pull the connectors off the motor. Note: The mowing head and mounting plate have to be removed to replace the motor -see 5.3. Installation is a reversal of the removal sequence. Note: Pay special attention to the following points. Top: Correct position of cable (FE 35) Bottom: Correct position of wiring (FE 40) - The mounting plate must engage the housing slots. - Position wires in the notches in the housing web. - Fit the connecting tube - see 4.2. FE 35, 40, 55, EC 70 13 3.7 Carbon Brushes (FE 35, FE 40) Top: 1 = Tab 2 = Spring Correctly positioned activating cord - On FE 35, hook activating cord onto adjusting lever and position it behind the pin. - Place the upper housing molding in position. Screw on the clamp nut. Insert mounting screws and tighten down to 1.2 Nm (0.9 Ibf.ft). Opening cover Bottom: 1 = Carbon brush 2 = Retaining tag The commutator is subject to normal wear. The friction generated by the carbon brushes causes the commutator surface to wear gradually and eventually leaves deep scores. The scores cause an increase in sparking between the carbon brushes and commutator. Therefore, before installing new carbon brushes, inspect the commutator for wear and replace the complete motor if necessary. - Remove the motor - see 3.6. - Use a small screwdriver to remove the cover. - Bend open the tab on the brush holder and remove the spring. Note: Carbon brushes must always be replaced in pairs. - Push the retaining rings in the brush holder slightly toward the mowing head so that the worn carbon brush can slip out of the brush holder. - Fit new carbon brush, push the spring into the brush holder and bend the tab back to the horizontal position. - Close the cover. - Install the motor - see 3.6. FE 35, 40, 55, EC 70 14 3.8 Switch Unit of Automatic Feed Mechanism (FE 40) Top: Solenoid mounting plate Bottom: Removing switch unit Top: Right angle connectors on switch unit Bottom: Switch unit assembly (original version) 1 = Thermistor Switch unit assembly (new version) 1 = Solenoid 2 = Solenoid mounting plate 3 = Switch unit 4 = Iron core 5 = Actuating pin The complete switch unit has to be replaced if any one of its components is faulty. The new and original parts cannot be combined. The new switch unit assembly can be identified as follows: The connecting wires between the switch unit and solenoid are yellow instead of red. No thermi- is fitted. - Fit the iron core, cross hole facing outward, in the solenoid. Important: All wires must be reconnected to their original terminals - see 3.1. - Remove the motor - see 3.6. - Take the solenoid mounting plate out of its seat in the housing. - Remove the switch unit from the housing molding. - Pull the right angle connectors off the switch unit. Installation is a reversal of the removal sequence. Note: A modified switch unit is installed to avoid the need to solder the switch unit's sensitive printed circuit board. FE 35, 40, 55, EC 70 3.9 Adjusting Automatic Feed Mechanism (FE 40) Potentiometer 15 3.10 Motor (FE 55, EC 70) Top: Switch Top: Lifting motor out of housing Bottom: Wires from motor Bottom: Correct position of wiring If the automatic feed mechanism malfunctions, its tripping point can be corrected on the potentiometer. - Remove upper housing molding – see 3.6. - Use a small screwdriver to rotate the potentiometer on the switch unit. Note: Turn clockwise = feed is activated when cutting line is shorter (later). Turn counterclockwise = feed is activated when cutting line is longer (earlier). - Refit upper housing molding. - Pull the drive tube off the adapter – see 4.3. - Remove the motor from the lefthand housing molding. - Remove the on/off switch from its seat in the left-hand housing molding. Installation is a reversal of the removal sequence. - Pull the wires from the motor off the switch terminals. Note: Reconnect both wires to the original terminals - see 3.1. Position the wires in the slot in the housing molding. FE 35, 40, 55, EC 70 3.11 Fanwheel 16 3.12 Adapter 3.13 Strain Relief Flap Top: Removing the fanwheel Top: Prying adapter off shaft Top: Removing strain relief flap Bottom: Press-fitted fanwheel a = 3.5 mm (0.14 in) Bottom: Installing the adapters Bottom: Torsion spring - Remove the motor - see 3.10. - Remove the motor - see 3.10. - Rest fanwheel on bench and use a piece of round stock (6 mm/ 1/4" dia.) to press it off the shaft. - Use a hot air blower (e.g. hair dryer) to heat the adapter and then pry it off the shaft with two screwdrivers. - Take the strain relief flap out of the left-hand half of the housing. - Press the fanwheel, blades first, onto the shaft until distance "a" is obtained. - Press adapter on to shaft as far as stop. - Remove the torsion spring from the flap. - Install the motor - see 3.10. - Install the motor - see 3.10. - When refitting the flap, make sure that torsion spring is properly seated. - Separate the two halves of the housing - see 3.4. FE 35, 40, 55, EC 70 4. SHAFT 4.1 Line Feed Lever/ 17 4.2 Top: Removing the connecting tube 1 = Cable Top: Activating cord on adjusting lever Bottom: Activating cord on line feed lever Connecting Tube / Loop Handle Correctly positioned activating cord Bottom: Cylindrical pin - Tie a piece of string (about 1000 mm/39 in long) to the activating cord. - Pull the activating cord out of the connecting tube so that the string is still inside the tube and can be used to fit the new activating cord. Installation is a reversal of the removal sequence. Note: After fitting the new activating cord, pass it behind the pin the connecting tube and around the pin in the housing molding. - Remove upper housing molding – see 3.6. - Remove the activating cord - see 4.1. - Remove the on/off switch - see 3.3. - Unhook activating cord from adjusting lever. - Remove the connecting tube and pull out the cable at the same time. - Remove the handle - see 3.2. - Unhook the activating cord from the line feed lever. - Pull the cylindrical pin out of the connecting tube. FE 35, 40, 55, EC 70 18 4.3 Drive Tube (FE 55, EC 70) Top: Removing clamp nut Top: Installing connecting tube (FE 35) 1 = Hole at end of slot Bottom: 1 = Clamp nut 2 = Loop handle Bottom: Installing connecting tube (FE 40) 1 = Slot Bottom: Removing the drive tube - Slip the clamp nut off the connecting tube. - On FE 35, fit connecting tube so that the cylindrical pin engages the hole at the end of the slot. - Take out the housing mounting screws and remove the righthand housing molding. - On FE 40, fit connecting tube so that the cylindrical pin engages the slot. - Raise the drive tube until the retaining block is clear of the recess in the left-hand housing molding. - Release clamp nut on loop handle and pull the loop handle off the connecting tube. Installation is a reversal of the removal sequence. Top: Housing mounting screws - Pull the drive tube off the adapter. Note: Pay special attention to the following points: FE 35, 40, 55, EC 70 19 4.4 1 = Retaining block 2 = Peg 3 = Recess in housing molding - To replace the drive tube, remove the bearing housing on the FE 55 or the gearhead on the EC 70 – see 5.1 or 5.2. Pull out the drive shaft, see 4.4, and remove the loop handle, see 4.5. Reassemble in the reverse sequence. Note: Push the drive tube onto the adapter. Fit peg of retaining block into hole in drive tube and engage retaining block in recess in housing molding. Torque down housing mounting screws to 5.5 Nm (4.0 Ibf.ft). Drive Shaft (FE 55, EC 70) Withdrawing flexible shaft (FE 55, EC 70) Drive shaft must project a = 15 mm (0.6 in) on FE 55 20 mm (0.8 in) on EC 70 The drive shaft is supported inside the drive tube in bearing bushes. It is not possible to replace the bearing bushes, i.e. a new drive tube has to be installed in the event of a fault or damage. - Pull the drive shaft out of the drive tube. - On FE 55, remove the bearing housing, see 5.1. On EC 70, remove the gearhead, see 5.2. Important: Apply the grease uniformly and thinly to the whole drive shaft. Do not pump grease directly into the drive tube. - Coat the drive shaft with STIHL multipurpose grease, see 6.2, before installation. - Push the drive shaft into the drive tube. Note: Push the drive shaft into the drive tube until dimension "a" is obtained (see illustration). If necessary, apply slight pressure to the shaft and rotate it slowly until it can be pushed in to the specified dimension. - Fit the bearing housing or gearhead. FE 35, 40, 55, EC 70 4.5 20 Loop Handle (FE 55, EC 70) Top: Clamp screw on loop handle Bottom: Removing the fixing Top: Pulling off handle hose Bottom: 1 = Loop handle 2 = Clamping block 1 = Clamp screw 2 = Square nut - Place the square nut in position and insert the clamp screw from the other side. Line up the loop handle and tighten down clamp screw firmly. - Take the clamp screw out of the loop handle. Remove the loop handle and clamping block from the drive tube. - To replace the handle hose, unscrew the fixing screw from the loop handle. - Turn the loop handle to one side and pull off the handle hose. - Refit the loop handle on the drive tube. Place the clamping block against the drive tube and slide it sideways into the loop handle (see illustration). FE 35, 40, 55, EC 70 5. CUTTING TOOL DRIVE 5.1 Bearing Housing (FE 55) Top: 1 = Clamp 2 = Deflector shield Bottom: 1 = Bearing housing 2 = Clamp - Remove the mowing head (if fitted). - Release screw on clamp and pull deflector shield off the bearing housing. - Release screw on bearing housing clamp and slip the clamp off the bearing housing. 21 Top: Fixing screw Top: Removing the circlip Bottom: Pliers 0811 611 8200 Bottom: Removing the washer - Take the fixing screw out of the bearing housing and pull bearing housing off the drive tube. - Remove the circlip from the output shaft. - Remove the washer from the output shaft. FE 35, 40, 55, EC 70 22 Top: Removing the output shaft Top: Pressing home plain bearing Bottom: Press arbor 4119 893 7200 Bottom: Pressing home plain bearing - Pull the output shaft out of the bearing housing. - Use press arbor to install the two plain bearings until they butt against shoulder on bearing housing. - Carefully drive the two plain bearings out of the bearing housing. Assembly is a reversal of the disassembly sequence. Note: Pay special attention to the following points: Top: Lining up holes in bearing housing and drive tube Bottom: Correct position of deflector shield in relation to bearing housing - Push bearing housing onto drive tube so that the holes line up. - Insert the fixing screw and tighten down to 3 Nm (2.2 Ibf.ft) . - Line up recess in neck of deflector shield with peg on bearing housing. Push deflector onto bearing housing as far as stop. - Torque down bearing housing clamp screw to 6.5 Nm (4.8 Ibf.ft). FE 35, 40, 55, EC 70 5.2 Gearhead (EC 70) 5.2.1 Disassembly Top: Unscrewing flanged nut Bottom: 1 = Thrust plate 2 = Cutting blade - Use 5 mm (0.2 in) drift to block the output shaft and unscrew the flanged nut. Note: Flanged nut has left-hand thread. - Take the thrust plate and cutting blade off the output shaft. 23 Top: Removing thrust plate Top: Removing deflector shield Bottom: 1 = Clamp 2 = Clamp screw 3 = Star knob screw Bottom: 1 = Washer 2 = Retainer 3 = Mounting screws 4 = Star knob screw - Take the thrust plate off the output shaft. - Remove the deflector shield from the gearhead. - Unscrew the clamp screw and star knob screw from the clamp and then remove the clamp. Note: The following three operations must be performed to replace the deflector shield: - Take the mounting screws out of the retainer, pull the star knob screw out of the bore and remove the washer. FE 35, 40, 55, EC 70 Top: Removing bearing bolt from depth wheel Bottom: 1 = Rubber flap 2 = Fastening screw - Unscrew the bearing bolt from the depth wheel and remove the wheel. - Take out the fastening screw and remove the rubber flap. 24 Top: Clamp screw Bottom: Pliers 0811 641 8380 - Release clamp screw on gearhead and pull the gearhead off the drive tube. - Remove the circlip from groove in input end of the gearhead. Top: Removing circlip from input end of gearhead Bottom: Removing circlip from output end of gearhead - Remove the circlip from groove in output end of the gearhead. - Heat the gearhead housing to about 110 to 140°C (230 -280°F). Remove the gearhead components from the input end first and then the output end by knocking the gearhead against a wooden base. FE 35, 40, 55, EC 70 25 Top: Removing output shaft Top: Pliers 0811 611 8200 Bottom: 1 = Bevel gear 2 = Ball bearing Bottom: Removing the circlip from the drive pinion - Press the output shaft out of the ball bearing. - Pull the ball bearing and bevel gear off the output shaft. - Remove the circlip from the drive pinion. Top: Pressing drive pinion out of ball bearings Bottom: Pinion set - Press the drive pinion out of the ball bearings. - Clean all parts and inspect them for signs of wear or damage. Note: The drive pinion and bevel gear are only available as matched pairs, i.e. as a pinion set. FE 35, 40, 55, EC 70 26 5.2.2 Assembly Top: 1 = Drive pinion 2 = Open ball bearing 3 = Sealed ball bearing Bottom: Ball bearing on output shaft - Heat the ball bearings for input end to about 50°C (120°F) and push them onto the drive pinion so that the open bearing locates against the pinion. - Fit the circlip in the groove. - Heat ball bearing for output end to about 50°C (120°F and push it onto the output shaft as far as stop. Top: Pushing bevel gear onto the output shaft Bottom: Fitting the sealed ball bearing in gearhead housing Top: Fitting the output shaft Bottom: Fitting the drive pinion - Push the bevel gear (teeth first) onto the output shaft. - Place the preassembled output shaft in position and press it home as far as stop. - To install the bearing and pinion set, heat the gearhead housing to about 140°C (285°F), e.g. on a heating plate or with a hot air blower. - Place the preassembled drive pinion in position and press it home as far as stop. - Push the sealed ball bearing into the housing as far as stop. Note: Make sure the teeth of the drive pinion and bevel gear mesh properly during installation. FE 35, 40, 55, EC 70 27 Top: Fitting gearhead on drive tube Screw plug for gear lubricant - - Bottom: Washers Fit the circlips in their respective grooves at the input and output ends of the gearhead housing. - Refit the rubber flap. - To fit the depth wheel, slip washer over the bearing bolt. Push the bearing bolt through the depth wheel, fit a washer at the other side and screw the bearing bolt into the deflector shield. Remove the screw plug from the gearhead, screw the tube of grease into position and fill the gearhead with grease. Note: Use STIHL gear lubricant, see 6.2, for lubrication of the bevel gear drive. - Position the deflector shield against the gearhead. Fit a washer on the clamp screw and place the clamp in position. Important: Fill the gearhead with approx. 20 g (3/4 oz) grease. - Fit a new self-locking nut and tighten it down firmly. Service note: Top up gearhead with grease (max. 5...10 g / 1/4 - 3/8 oz) only if no grease is visible on the inside of the screw plug. - Unscrew the tube of grease, refit the screw plug and tighten it down firmly. Fitting the clamp 1 = Deflector shield 2 = Washer - Slide the gearhead onto the drive tube -turn the output shaft back and forth at the same time so that the square end of the drive shaft engages the square socket in the drive pinion. - Push the gearhead as far as stop and line it up. Tighten down the two clamp screws to 7.5 Nm (5.5 Ibf.ft). - Refit the cutting blade by reversing the removal sequence. FE 35, 40, 55, EC 70 5.3 28 Mowing Head / Motor Mounting Plate (FE 35, FE 40) Top: Prying off the driver Removing cap Bottom: Removing mowing head housing Top: Prying out support roller Bottom: Mounting screws of motor mounting plate The mowing head housing and driver should be installed with the motor removed. This avoids excessive bearing loads when pressing on the driver. - Remove the motor - see 3.6. - Clamp the motor, with the mowing head facing up, in a vise. Important: Use protective jaws. Take care not to damage winding. - Hold the mowing head housing steady. - Press the cap downward, turn it counterclockwise as far as stop and lift it away. - Heat the driver (e.g. with hot air blower or hair dryer) and use two screwdrivers to lever it off (see illustration). -Take the spool out of the mowing head housing. - Remove the mowing head housing. - To replace the motor mounting plate, perform the following operations: - Carefully pry the support roller (above the mounting screw) out of its seat. - Take the mounting screws out of the motor mounting plate and remove the mounting plate. FE 35, 40, 55, EC 70 29 Top: Mowing head housing with retrofitted sleeves Adapter sleeve Bottom: Mowing head housing with aluminum sleeves Top: 1 = Slot in mowing head housing 2 = Adapter sleeve Bottom: Pressing on the driver - If necessary, use a 2.5 mm (0.10 in) punch to drive the adapter sleeve out of the rotor shaft. Assembly is a reversal of the disassembly sequence. Note: Pay special attention to the following points: - Torque down mounting screws of motor mounting plate to 1.8 Nm (1 .3 Ibf.ft). - Carefully press the support roller (shorter bearing pin must face rotor shaft) into its seat. Note: Mowing head housings with aluminum sleeves (for nylon line) are installed from machine numbers X 19 966 870 (FE 35) and X 19 971 252 (FE 40). If the trimmer still has a mowing head housing with retrofitted sleeves, it is advisable to install a mowing head housing with aluminum sleeves for improved nylon line control and better heat dissipation. - Fit the mowing head housing so that the adapter sleeve engages the slot. - Press the driver onto the rotor shaft as far as it will go. - Fit the spool, projecting edge facing up, so that the nylon lines locate in the sleeves. - Hold the mowing head housing steady. - Fit the cap in position, press it downward and turn it clockwise as far as stop. - Install the motor - see 3.6. FE 35, 40, 55, EC 70 30 6. Special Servicing Tools and Aids 6.1 Special Servicing Tools No. Part Name Part No. 1 Crimping tool 5910 890 8210 Attaching connectors to electric wires 2 Pliers A 10 0811 611 8200 External circlip on bearing housing and drive pinion 3 Press arbor 4119 893 7200 Installing plain bearings in bearing housing 4 Pliers A 19 0811 641 8380 Internal circlip on gearhead Application FE 35, 40, 55, EC 70 6.2 No. 31 Servicing Aids Part Name Part No. Application 1 Electrician's repair kit 0000 007 1013 2 STIHL multipurpose grease 0781 120 1109 Lubricating drive shaft (FE 55, EC 70) 3 STIHL gear lubricant 0781 120 1117 Lubricating gearhead (EC 70)