14. FRONT WHEEL/FRONT SUSPENSION/ STEERING SYSTEM … · STEERING SYSTEM 14-13 MXU 250R/300R Remove the two nuts and two bolts attaching the lower front arm, then remove the lower

14. FRONT WHEEL/FRONT SUSPENSION/ STEERING SYSTEM

14-0

MXU 250R/300R

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FRONT WHEEL/FRONT SUSPENSION\STEERING SYSTEM

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SERVICE INFORMATION------------------------------------------------ 14- 2TROUBLESHOOTING----------------------------------------------------- 14- 2FRONT WHEEL------------------------------------------------------------- 14- 3FRONT WHEEL HUB------------------------------------------------------ 14- 4FRONT SUSPENSION ----------------------------------------------------- 14- 8TIE-ROD---------------------------------------------------------------------- 14-15HANDLEBAR --------------------------------------------------------------- 14-18STEERING COLUMN------------------------------------------------------ 14-21

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14-1

MXU 250R/300R


14-2

MXU 250R/300R

SERVICE INFORMATIONGENERAL INSTRUCTIONS• Jack the machine front wheel off the ground and be careful to prevent the machine from falling

down.• During servicing, keep oil or grease off the brake disk• Inspect the brake system before riding.

SPECIFICATIONS Unit: mm (in)

Item Standard Service LimitRadial ⎯ 2 (0.08)Axial ⎯ 2 (0.08)

Tie rod length 299.5±0.5 (11.98±0.02) ⎯Rod-end (tie rod) angle 180º ⎯

TORQUE VALUESSteering stem nut 7 kgf-m (70 Nm, 50 lbf-ft)Front swing arm nut 4.5 kgf-m (45 Nm, 32 lbf-ft)Front wheel nut 4.5 kgf-m (45 Nm, 32 lbf-ft)Front wheel hub nut 7 kgf-m (70 Nm, 50 lbf-ft) Castle nutKnuckle ball joint nut 3 kgf-m (30 Nm, 22 lbf-ft) Castle nutTie-rod ball joint nut 2 kgf-m (20 Nm, 15 lbf-ft Castle nutFront shock absorber mount bolt 4 kgf-m (40 Nm, 29 lbf-ft)

SPECIAL TOOLSOil seal and bearing install E014Tie-rod ball join remover F011Ball join remover F012

TROUBLESHOOTINGHard steering (heavy) Front wheel wobbling•Insufficient tire pressure • Bent rim

• Excessive wheel bearing play • Bent spoke plate

• Faulty tireSteers to one side or does not track straight • Improperly tightened axle nut• Uneven front shock absorbers Soft front shock absorber• Bent front arm • Weak shock springs• Bent steering knuckle • Insufficient damper oilFront shock absorber noise• Slider bending• Loose arm fasteners• Lack of lubrication

Front wheel rim run out


14-3

MXU 250R/300R

FRONT WHEELREMOVAL AND INSPECTIONPlace the machine on a level place.Remove four nuts attaching the front wheelhub and front wheel.Elevate the front wheels by placing asuitable stand under the frame.

Measure the wheel run out.Replace wheel or check bearing play if outof specification

Rim run out limits:Vertical: 2 mm (0.08 in)Lateral: 2 mm (0.08 in)

INSTALLATIONWhen reinstalling a wheel, tighten thewheel nuts in a crisscross (rather than acircular) pattern.

Torque: 4.5 kgf-m (45 Nm, 32 lbf-ft)

Support the machine securely so thereis no danger of it falling over.

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Nuts

Be sure the tapered side of the wheelnuts face the wheel rim.

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14-4

MXU 250R/300R

FRONT WHEEL HUBREMOVAL AND INSPECTIONPlace the machine on a level place.Remove the front wheel (page 14-3) andcaliper. (page 13-9)Elevate the front wheels by placing asuitable stand under the frame.

Remove the nut cap.Remove the cotter pin.Remove nut from the front wheel hub andthen remove front wheel hub.

DISASSEMBLYRemove the outside collars.Inspect the dust seals for wear or damage.If any defects are found, replace the dustseal with a new one.Remove the dust seals by a flat-head screwdriver.

Support the machine securely so thereis no danger of it falling over.

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Nut

Cotter Pin

Outside Collar

Dust SealOutside Collar

Dust Seal

Nut Cap

Place a wood block against the outeredge to protect this edge.

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14-5

MXU 250R/300R

Inspect the bearings for allow play in thefront wheel hub or the wheel turns roughly.

If any defects are found, replace thebearings.

Remove the bearings using a generalbearing puller.

Bearing

Bearing


14-6

MXU 250R/300R

Remove the distance collar from the frontwheel hub.

ASSEMBLYInstall the left new bearing and dust sealinto the front wheel hub.

Special tool:Oil seal and bearing install E014

Install the distance collar.

Distance Collar

Be sure the tapered side of the distancecollar face the wheel.

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Distance Collar

Apply the grease onto the oil seal lips,bearing.

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14-7

MXU 250R/300R

Install the right new bearing and dust sealinto the front wheel hub.

Special tool:Oil seal and bearing install E014

INSTALLATIONReverse the “FRONT WHEEL HUBREMOVAL AND INSPECTION”procedures.

Tighten the front wheel hub nut.

Torque: 7 kgf-m (70 Nm, 50 lbf-ft)

Install the cotter pin and band ends of cotterpin.

Always use a new cotter pin.＊

Do not loosen the wheel hub nut aftertorque tightening. If the wheel hub nutgroove is not aligned with the cotter pinhole, align groove with the hole bytightening up on the wheel hub nut.Always use a new cotter pin.

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Apply the grease onto the oil seal lips,bearing.

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Apply grease onto the bearing and dustseal lips of the wheel panel.

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•Do not allow the bearings to tilt whiledriving them in.

•Do not strike the center race or balls ofthe bearing. Contact should be madeonly with the outer race.

•Pack all bearing cavities with grease.•Drive in the bearing squarely with the

sealed end facing out.

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14-8

MXU 250R/300R

FRONT SUSPENSIONREMOVAL AND INSPECTIONElevate the front wheels by placing asuitable stand under the frame.

Remove the front wheel (page 14-3), caliper(page 13-9) and front wheel hub. (page 14-4)

Remove the two bolts and brake diskprotection plate.

Remove the cotter pins, washer and nutsfrom tie-rod, upper and lower front arms.

Release the tie-rod ball joint off the knuckle,using the special tool according to thefollowing instructions.

Special tool: Tie-rod ball join remover F011

Apply grease to the ball joint remover at thepoint shown.This will ease installation of the tool andprevent damage to the pressure bolt threads.Insert the jaws carefully, making sure thatyou do not damage the ball joint boot.Adjust the jaw spacing by turning thepressure bolt.Tighten the pressure bolt with a wrenchuntil the ball joint stud pops loose.Remove the knuckle from the upper andlower arms

Support the machine securely so there isno danger of it falling over.

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Nut

Cotter Pin Nuts Cotter Pin

Tie-rod

Nut

Plate Bolts

Apply grease

Tie-rod Ball Join Remover


14-9

MXU 250R/300R

Release the ball joints of the upper andlower arms off the knuckle, using thespecial tool according to the followinginstructions.

Special tool: Ball join remover F012

Apply grease to the ball joint remover at thepoint shown.This will ease installation of the tool andprevent damage to the pressure bolt threads.Insert the jaws carefully, making sure thatyou do not damage the ball joint boot.Adjust the jaw spacing by turning thepressure bolt.Tighten the pressure bolt with a wrenchuntil the ball joint stud pops loose.Remove the knuckle from the upper andlower arms

Inspect the steering knuckle for cracks,pitting or damage.If any defects are found, replace the steeringknuckle with a new one.

Ball Join Remover

Apply grease


14-10

MXU 250R/300R

Remove the front shock absorber upper mountand lower mount bolts/nuts, then remove thefront shock absorber and bush.

Inspect the shock absorber rod.Bends/damage →Replace the shockabsorber assembly.Inspect the shock absorber.Oil leaks →Replace the shock absorberassembly.Inspect the spring of the shock absorber bymove the spring up and down.Fatigue →Replace the shock absorberassembly.Inspect bush.Wear/damage →Replace.

Bush

Shock Absorber

Bolts/Nuts


14-11

MXU 250R/300R

Check the upper front arm brackets of theframe.If bent, cracked or damaged, repair orreplace the frame.Check the tightening torque of the frontarms securing nuts.


Check the upper front arm side play bymoving it from side to side.If side play noticeable, replace the innercollars and bushes as a set.

Check the front arm vertical movement bymoving it up and down.If vertical movement is tight, binding orroughs, replace the inner collars and bushesas a set.

Remove the band and then disconnect thefront brake fluid tube from the upper frontarm.Remove the two nuts and two boltsattaching the upper front arm, then removethe upper front arm and bushes.

Band

Front Brake Fluid Tube Bolts


14-12

MXU 250R/300R

Inspect the front arm.Cracks/bends/damage →Replace.

Inspect bushes.Wear/damage →Replace.

Check the lower front arm brackets of theframe.If bent, cracked or damaged, repair orreplace the frame.Check the tightening torque of the frontarms securing nuts.


Check the lower front arm side play bymoving it from side to side.

If side play noticeable, replace the innercollar and bushes as a set.

Check the lower front arm verticalmovement by moving it up and down.If vertical movement is tight, binding orroughs, replace the inner collar and bushesas a set.

Do not attempt to straighten a bent arm,this may dangerously weaken the arm.

＊Bushes


14-13

MXU 250R/300R

Remove the two nuts and two boltsattaching the lower front arm, then removethe lower front arm and bushes.

Inspect the lower front arm.Cracks/bends/damage →Replace.

Inspect bushes.Wear/damage →Replace.

Bolts

Bushes

Do not attempt to straighten a bent arm,this may dangerously weaken the arm.

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14-14

MXU 250R/300R

INSTALLATIONReverse the “FRONT SUSPENSIONREMOVAL AND INSPECTION”procedures.

Install the lower and upper front arms nutsonto the frame and tighten the nuts.


Install the steering knuckle onto the upperand lower front arms and tighten the nuts.


Install the tie-rod and washer onto thesteering knuckle and tighten the nut.


Install the all cotter pins and band ends ofcotter pins.

Apply the grease onto the bush, then installthe shock absorber and tighten the uppermount and lower mount bolts.


Install the front wheel hub (page 14-7),caliper (page 13-11) and front wheel. (page14-3)

Apply the grease onto the bushes andinner collars

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14-15

MXU 250R/300R

TIE-RODREMOVAL/INSPECTIONRemove the cotter pin and nut attaching thetie-rod and steering column.Remove the cotter pin, washer and nutattaching the tie-rod and steering knuckle.Then remove tie-rods, using the special tool(page 14-8).

Special tool: Tie-rod ball join remover F011

Inspect the tie-rod.Bend/damage →Replace.

Check the tie-rod end movement.Tie-rod end exists free play or turnsroughly →Replace.Check the tapered surface of the tie-rod end.Pitting/wear/damage →Replace.

Nut Cotter Pin NutCotter Pin


14-16

MXU 250R/300R

Adjust the tie-rod length.Adjustment steps:(The following procedures are done on bothtie-rods, right and left.)Loosen the lock nuts.Adjust the tie-rod length by tuning both tie-rod ends.

Tie rod length:299.5±0.5 mm (11.98±0.02 in)

Set the rod-end (steering column side) in anangle where the indentation surface of thetie-rod is parallel to the rod-end shaft, andthen tighten the lock nut.


Set the other rod-end (knuckle arm side) inan angle as shown (right-hand tie-rod andleft-hand tie-rod), and then tighten the locknut.Rod-end (tie rod) angle: 180º


Lock Nut Lock NutIndentation Surface

To Steering Column

To Knuckle Arm

The threads on both rod-end must be ofthe same length.

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After making adjustment on both tie rodsbe sure to mark them R and L foridentification.

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14-17

MXU 250R/300R

INSTALLATIONReverse the “REMOVAL/INSPECTION”procedures.Install the tie-rod and washer onto thesteering knuckle and steering column, thentighten the nuts.

Torque:Steering knuckle side:

2 kgf-m (20 Nm, 15 lbf-ft)Steering column side:

2 kgf-m (20 Nm, 15 lbf-ft)

Install the all cotter pins and band ends ofcotter pins.

Indentation Surface


Be sure that the rod-end on theindentation surface side is connected tothe steering knuckle.

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14-18

MXU 250R/300R

HANDLEBARREMOVAL/INSPECTIONRemove the following parts:Seat, front cover, fuel tank cover, frontfender and handlebar cover.Refer to the “FENDERS” section in theCHAPTER 2

Remove the right and left master cylinderand remove bands then disconnect the rearand front fluid tube from the handlebar.

Remove the two screws and remove thehandlebar switch.Remove the two screws and remove throttleunit.

Remove the four handlebar holder bolts,then remove handlebar cover and handlebarholder.

Bolts Brake Fluid Tube

Screws Screws

Bolts Handlebar Holder


14-19

MXU 250R/300R

INSPECTIONInspect the handlebar.Cracks/bends/damage →Replace.

INSTALLATIONInstall handlebar and handlebar holder, thentighten the four bolts.


•Be sure the upper handlebar holdermark face to front.

•First tighten the bolts on the front sideof the handlebar holder, and thentighten the bolts on the rear side.

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Mark

Holder Surface

Forward Mark

＊Align the mark on the handlebar with thelower handlebar holder surface.

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14-20

MXU 250R/300R

Install the handlebar switch by aligning thepin on the handlebar switch with the hole inthe handlebar and then tighten the twoscrews.

Place the right and left brake mastercylinder on the handlebar and install themaster cylinder holder with the “UP” markfacing up, aligning the punch mark on thehandlebar with the holder joint seam. Firsttighten the upper bolt and then tighten thelower blot.

Torque: 1.2 kg-m (12 Nm, 8.6 lbf-ft)

Hole

Pin

Joint SeamPunch Mark

“UP” Mark


14-21

MXU 250R/300R

Install the throttle unit by aligning the upperholder lip with the mark in the handlebarand then install the lower holder and tightenthe two screws.

STEERING COLUMNREMOVAL AND INSPECTIONRemove handlebar. (page 14-18)

Remove the two bolts and remove the cableholder, steering brackets and dust seal.

Mark

Upper Holder Lip

Bolts Steering Bracket

Steering Bracket Dust Seal


14-22

MXU 250R/300R

Remove the cotter pins and nuts attachingthe tie-rods, then disconnect the tie-rodsfrom the steering column.

Remove the cotter pin and nut attaching thesteering column under the frame body, thenremove steering column and collar.

Inspect the collar, dust seals, snap ring(under the dust seal) and bearing.Wear/damage →Replace.

Cotter Pin Nut

Cotter Pin

Nut

Dust SealCollar

BearingDust Seal Snap Ring


14-23

MXU 250R/300R

Inspect the steering column.Bends/damage →Replace.

Inspect the steering brackets and oil seal.Wear damage →Replace.

INSTALLATIONReverse the “REMOVAL” procedures.

Install the steering column and collar, thentighten the nut under the frame body.


Install the cotter pin and band ends of cotterpin.

Assembly the steering column and tightenthe two bolts.


Install the tie rods and washer, then tightenthe nut.


Install the cotter pins and band ends ofcotter pins.

Refer to the “TOE-IN ADJUSTMENT”section in the CHAPTER 3 to adjust toe-in.

Do not attempt to straighten a bent shaft,this may dangerously weaken the shaft.

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Apply the grease onto the collar, dustseals, and bearing.

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Documents

14. FRONT WHEEL/FRONT SUSPENSION/ STEERING SYSTEM … · STEERING SYSTEM 14-13 MXU 250R/300R Remove the two nuts and two bolts attaching the lower front arm, then remove the lower