Presentation on theme: "Front Steer Axle Technical Training"— Presentation transcript:
1Front Steer Axle Technical Training Welcome screen. Introduce your self and ArvinMeritor.
2Meritor Front Non-Drive Steer Axle The front non-drive axle is a solid axle system designed to support the weight of the front of the vehicle, provide a center point for the tire and wheel assemblies, and provide steering capability to the vehicle.Current Meritor front non-drive steer axles do not include suspension springs. The suspension springs are provided by the vehicle manufacturer.Describe basic purpose of the axle.
3“Easy Steer” Front Axle The term ‘Easy Steer” relates to the low friction composite knuckle pin bushings, made of acetate resin polymer. These bushings reduce steering effort and provide longer life.**Bushing inspection and service is covered later in this program.Self explanatory.
4Model Identification Early Meritor steer axles Axle build information is indicated on the axle identification tag. The tag is fastened to the center front surface of the axle beam. There are four numbers listed: Model number Customer number Serial number Build dateAn example of a model number is; FF961 LX122.Discuss the importance of the model number for ordering parts. The model number also identifies if Meritor installed the brakes, wheel ends, etc.
5IdentificationThe axle model number identification plate is located on the axle center.Example of and location of tag.
6Model Identification, continued; Later Meritor steer axlesAxle build information on the later Meritor axle is located on a similar tag as the early axle.The tag contains similar information except for the model number difference.An example of a model number is; MFS122015NX122This information is needed when ordering replacement partsAll new Meritor designed axles will be identified by the new MFS model number system. All existing Rockwell designed axles will keep the “F” model number system previously discussed.
7FF 961 DescriptionThe Meritor FF 961 axle is standard with bottle spindles for conventional wheel ends.Meritor supplies most axles to the OEM’s less brakes and wheel end equipment.Discuss the difference between bottle and barrel spindle. Bottle has a large inner bearing and small outer bearing. Barrel has the same bearing size for both outer and inner.
8FF 961 ComponentsDiscuss general components; IE: beam, cross tube, tie rods, tie rod ends, steering arm (right hand drive axle), brake chambers, ASA’s.
10FF 961 Inspection Refer to MM02, Lubrication and Maintenance Section. Use Table C to determine vehicle vocationUse Table D for lubrication, inspection and maintenance schedule.Front axle components maintenance inspection, lubrication procedures, and fastener torque checks vary dependant upon the vehicle vocation. Table C in the next slide identifies the vocation and table D identifies the time or mileage for the service procedure.
11FF 961 Inspection, Table CDetermine the vocation group number from table C. Use the group number for table D.
12FF 961 Inspection, Table D; Tie Rod Ends Inspect and lubricate tie rod ends per the service intervals listed. Note the reference to power washing.
13FF 961 Inspection, Table D; Tie Rod Assembly Inspect the tie rods for looseness per the service intervals listed.
14FF 961 Inspection, Table D; Miscellaneous Components Inspect and lubricate the listed components as noted.
15FF 961 Inspection, Table D; Knuckle Vertical End Play Inspect the steering knuckle vertical end play per the schedule above.
16FF 961 Inspection, Table D; King Pins, Draw Keys and Torque Requirements Inspect the upper and lower king pin bushing wear per the schedule above. Also, re-torque the draw key nuts per the “new vehicle” and “in-service vehicle” schedule above.
17Wheel Bearing End Play Inspection Measure end play by pushing/pulling on each side of the hub or drum while looking at the dial indicator.If end play is not within inch, adjust the wheel bearings.Fleet recommended interval for checking wheel bearing end play is 1 year or 100,000 miles.
18Tie Rod InspectionThe tie rod has right-hand threads on one end and left hand threads on other end.General tie rod installation information.
19Tie Rod InspectionTie rod threads must visible the entire length of the cross tube slot.Check tie rod movement by hand.Self explanatory.
20Tie Rod InspectionIf movement is more than inch, tie rod end replacement is required.If movement is noted, check actual reading with a dial indicator. Use hand movement to check this reading.
21Tie Rod Inspection Check for missing cotter pin. Check for damaged or torn boot.Self explanatory.
22Draw Key InspectionMake sure draw key is installed completely and the locknut is tightened to the specified torque. If the draw key is not installed correctly, the king pin and the axle center will be damaged.Tighten the draw key nuts from lb-ft at the following intervals.After the first 6,000 miles of new vehicle operation.Every 36,000 miles of operation.Self explanatory.
23Knuckle Vertical End Play New or rebuilt axles, inch.In-service axles, inch.Self explanatory.
24King Pin Bushing Wear Measure both upper and lower bushing for wear. Replace both bushings if wear is greater than inch.See MM2 for bushing replacement procedures.NOTE: When Easy Steer Bushings are replaced they must be reamed for proper fit.King pin bushings must be checked individually; upper and lower, with a dial indicator. When replacing the Easy Steer bushings stress that they must be properly reamed with the correct size reamer after installation in the spindle. Follow the procedure in MM 02. Reamer tool is available through Kent-Moore.
25Wheel Speed Sensor Adjustment The sensor must be reset each time the wheel end is removed to obtain he proper sensor-to-tone wheel gap.For sensor adjustment, push sensor in until it contacts the tone wheel. The wheel run-out will push the sensor back away from tone wheel for proper adjustment.See MM02 for sensor replacement.NOTE: If driver reports indicate the ABS light has been coming ON, and ABS diagnostics indicate the sensor gap is out-of-adjustment, check for possible wheel-end looseness as the cause.Self explanatory.
26Vehicle Pre-Alignment Inspection See MM2 for pre-alignment inspection.Wheel and tire conditionFront suspension condition (as shown previously in this program)Rear axle and rear suspension conditionAxle alignment should be a part of routine vehicle maintenance for maximum tire life. Component condition must be inspected prior to checking alignment.
27Alignment Check, ToeToe-in is when wheels are closer together in back than in front.Toe-out is when the wheels are closer together in back than in front.Describe toe.
28Alignment Check, ToeSteer axle toe is adjustable to reduce wear to the leading edge of the tire and also to avoid road wander.Excessive toe-in wears the outside edge of tires.Excessive toe-out wears the inside edge of the tires.Describe toe purpose and results of excessive toe.Toe is adjusted in a static, unloaded condition so that the tires will run in a straight line under a dynamic, loaded condition.
29Alignment Check, Toe Specifications Vehicle unloaded: 1/16” toe in. Most tire wear is caused by incorrect toe settings.See MM02 for procedures to measure and adjust toe.Toe adjustment is the responsibility of the vehicle manufacturer.With the vehicle unloaded both Meritor and TMC recommend 1/16” toe in. This is a target value.
30Alignment Check, Camber Angle Camber is the angle of the tire in relation to the ground.Positive camber occurs when the distance between the top of wheels is greater than the distance between the bottom of the wheels at ground level.A small amount of positive camber is built into the axle beam and knuckle because camber changes with load.Camber is listed as the least contributing factor to tire wear in a heavy vehicle. Toe and tandem alignment are the top two contributors to tire wear.This results in a zero or neutral camber angle when the vehicle is operated at the normal load.
31Alignment Check, Camber Angle; 1993 and later axles Axle installed in vehicle.Left side (roadside) and right side (curbside):+3/16 degreeto –11/16 degree final reading.TMC recommends; less than ¼ degree either side.The camber angle is not adjustable. It is machined into both the axle beam and the knuckle.Camber angle changes normally involve bending the axle beam, which will void the axle manufacturers warranty. If the measurement exceeds this value consult the vehicle, axle and/or alignment equipment manufacturer. Camber angle is the only alignment measurement that Meritor is responsible for.
32Alignment Check, Caster Angle Caster is the tilt of the king pin center line when viewed from the side of the vehicle.The caster angle is the angle from the vertical position to the center line of the king pin. If the top of the king pin axis is toward the rear of the vehicle, the caster is positive.Self explanatory.
33Alignment Check, Caster Angle A slight positive caster creates a self-aligning action that helps to stabilize the vehicle after turning and it for driving straight ahead.Too much caster will increase steering effort or may amplify a shimmy condition.Caster does not normally contribute to tire wear.
34Alignment Check, Caster Angle Adjust caster according to vehicle manufacturer’s procedure. Refer to vehicle manufacturer’s specification for caster angle.Generally vehicles with power steering are +2 to +4 ½ degree caster.TMC recommends; Left +3 ½ and Right +4 degree.Caster is the responsibility of the vehicle manufacturer.Self explanatory.
35Alignment Check, Ackerman Angle When turning, the inner wheel must turn at a greater angle than the outer wheel.This angle is the turning radius angle (often called the Ackerman angle).The angle is built into the design of the tie rod arms, the tie rod ends and the cross tube assembly to give the best possible road contact and to minimize tire wear during turns.A fleet would not normally check ackerman angle geometry. This is placed in the program for information purposes only. However, reinforce the fact that if the fleet changes wheel base or replaces tie rods on an axle they could affect ackerman angle and induce a tire wear issue. If the wheel base is changed the fleet should consult the OEM for recommendations on ackerman angle. If tie rods are changed replace like for like to maintain the original ackerman angle.
36Alignment Check, Ackerman Angle If angle is not within specifications, premature tire wear will occur.Ackerman angle is not adjustable. Hard parts must be replaced to set the proper angle for a particular OEM and wheelbase.A fleet would not normally check ackerman angle geometry. This is placed in the program for information purposes only. However, reinforce the fact that if the fleet changes wheel base or replaces tie rods on an axle they could affect ackerman angle and induce a tire wear issue. If the wheel base is changed the fleet should consult the OEM for recommendations on ackerman angle. If tie rods are changed replace like for like to maintain the original ackerman angle.
37Lubrication Refer to MM02, Lubrication and Maintenance Section. Use Table E for lubrication specifications.Use Table F for axle greasing intervals and specifications.Use Table G for wheel end oil change intervals and specifications.Self explanatory.
41LubricationKing PinsMake sure the tires touch the ground. Do not raise the vehicle.Clean off all grease fittings prior to lubrication.Lubricate the pins through the grease fittings on the top and bottom of the knuckle.Lube the king pin bushings with the axle loaded. This assures that grease enters the lower thrust bearing.Apply lubricant until new lubricant comes from the thrust bearing seal and the upper shim pack.
42Lubrication Procedure Tie rodsMake sure the tires touch the ground.Apply the lubricant through grease fittings on assembly.Apply the lubricant unit new lubricant comes from the boot.Axle loaded.
43Grease Lubricated Wheel Bearings Remove the old lubricant from all parts.Discard seals.Replace worn or damaged bearings.Force the specified lubricant from the large end of the cones into the cavities between the rollers and cage.Pack the hub between the bearing cups with lubricant to the level of the smallest diameter of the cups.In order to determine the condition of the grease in a grease lubricated wheel bearing, the hub cap and outer bearing must be removed. This procedure covers complete re-greasing of the hub and bearings.
44Oil Lubricated Wheel Bearings Check the level on the cap. If the oil level is not at the specified level on the cap, remove the fill plug. Add the specified oil until the oil is a the correct level.Also, check the condition of the lubricant.
45Diagnostics, General Items Most front axle issues are first noted as tire wear. However, other vehicle systems can contribute to tire wear. This will be discussed further in the next few slides.
46Diagnostics, General Items Continued from previous slide.
47Diagnostics, Tire WearConsult the TMC “Radial Tire Conditions Analysis Guide” for tread wear and tire conditions information.Most front axle issues are first noted as tire wear. However, other vehicle systems can contribute to tire wear. The TMC Radial Tire Conditions Guide is a very useful tool for diagnosing tire wear issues.
48Diagnostics, Tire WearTMC “Radial Tire Conditions Analysis Guide” content example.To receive a manual call 800 ATA-LINE and ask for item number T0121.Each page in the manual covers; appearance, probable cause, example photo and figure, and corrective action. It must be purchased and is under $
49SummaryThis program has provided technical information on ArvinMeritor front non-drive steer axle, FF961Front axle product overview, inspection, lubrication, and diagnostic information was presentedWhat additional information do you require that was not covered in the presentation?Questions or comments?Re-state the objectives for the program. In the beginning of the class you asked the participants “what they wanted out of the program”. If items were written down discuss those items now. Ask for any other questions or issues the customer may have regarding the FF 961 non-drive steer axle.
50Where to Get More Information Other training sessionsArrange with your DSMMaintenance ManualsTechnical BulletinsTechnology White PapersProduct VideosTechnical Library CDARM Web SiteCustomer ServiceTMC Recommended Practices ManualVehicle manufacturerSelf explanatory.
51ArvinMeritor publications can be found on ArvinMeritor’s website atAt the home page, in the lower right hand corner, listed under “products & services”, click on “Tech Library”.At this web page listed in the left hand column under “TECH LIBRARY” are reference material for your use.Click on the specific topic, then click on the specific sub topic.A list of publications referencing that sub topic will be displayed in the center of the web page.Select the item by clicking on it and the publication will launch onto your computer screen.Self explanatory.