TC Series Front Axle Blue Bird Corporation assumes sole responsibility for ensuring that the information provided herein is accurate to the best of its knowledge at the time of printing. In keeping with its policy of continual product improvement, Blue Bird reserves the right to change product information without notice and without incurring obligation. Some information contained in this section has been re-published from the following publications: Spicer Heavy Axle and Brake Division, Spicer Gold Series Front Axles Service Manual, Spicer/Dana, Form #SHABD 894-3. Contents TC Series Front Axle... 1 Spicer Heavy Axle and Brake Division, Spicer Gold Series Front Axles Service Manual, Spicer/Dana, Form #SHABD 894-3... 1 Contents... 1 List of Figures... 1 Safety... 2 Specifications... 3 Torque Chart... 3 Special Tools... 4 Lubrication... 4 Service Parts and Axle Identification... 5 Precautions and King Pin Wear Limits... 7 Maximum Limits for Front Axle King Pin... 8 King Pin Bushing Replacement... 9 Steering Knuckle Removal... 9 King Pin Bushing Removal... 10 King Pin Bushing Installation... 10 King Pin Seal Installation... 11 Steering Knuckle Installation... 11 Steering Knuckle Stop Adjustment... 12 Tie Rod Inspection and Replacement... 13 Remove Tie Rod Assembly and Tie Rod Steering Arm... 14 Install Tie Rod Steering Arm and Tie Rod Assembly... 14 Wheel Bearing Adjustment... 16 Front Axle Wheel Alignment and Balance... 16 List of Figures Figure 1 Model Identification Numbering System5 Figure 2 Exploded View of Axle Steering Knuckle Assembly and Inspection Guidelines... 6 Figure 3 Identification Tag Type and Location... 7 Figure 4 Typical Steering Knuckle... 7 Figure 5 King Pin Bushing Wear Measurement... 8 Figure 6 Spindle Vertical End Play Check... 8 Figure 7 Removing Draw Key... 9 Figure 8 Removing Steering Knuckle Cap... 9 Figure 9 Removing King Pin... 9 Figure 10 Bushing Removal... 10 Figure 11 Installing Pre-sized Bushings... 10 Figure 12 Bushing Seating Depth... 10 Figure 13 King Pin Bushing Seal Installation... 11 Figure 14 Thrust Bearing Seal Installation... 11 Figure 15 Sealed Thrust Bearing... 11 Figure 16 Spindle Vertical End Play Check... 11 Figure 17 Draw Key Installation to Front of Axle... 12 Figure 18 Steering Stop Adjustment... 12 Figure 19 Typical Tie Rod... 13 Figure 20 Set Up Dial Indicator... 13 Figure 21 Separate Rod End from Rod Arm... 14 Figure 22 Proper Indexing of Tie Rods... 15 Figure 23 Types of Tie Rod Clamps... 15 010-1
Safety WARNINGS and Cautions You must adhere to the WARNINGS and Cautions to work safely. The Warnings and Cautions listed in this manual are emphasized at point of use. These should be required prior to performing the maintenance step following the WARNING or Caution to prevent personal injury or equipment damage. Minor personal injury can result or a part, an assembly, or the engine can be damaged if the Caution instructions are not followed. SERIOUS PERSONAL INJURY OR EXTENSIVE PROPERTY DAMAGE CAN RESULT IF THE WARNING INSTRUCTIONS ARE NOT FOLLOWED. MOST FRONT AXLE SERVICE PROCEDURES REQUIRE THE VEHICLE TO BE LIFTED OFF THE GROUND AND SUPPORTED BY ALTERNATE MEANS. UNDER THESE CIRCUMSTANCES, ALWAYS USE LIFTING EQUIPMENT RATED AT, OR HIGHER THAN, THE VEHICLE WEIGHT. DO NOT RELY ON A HYDRAULIC JACK AS THE ONLY SUPPORT DURING SERVICING. A MALFUNCTION IN A HYDRAULIC JACK MAY RESULT IN THE VEHICLE SUDDENLY DROPPING TO THE GROUND. ALWAYS HAVE A SAFETY BACKUP TO SUPPORT THE WEIGHT OF THE VEHICLE. 010-2
Specifications, Torques and Special Tools Specifications Spicer Model I-120S A/S G and I-146SA/S G King Pin Bushing Diameter I.D. 1.8608 1.8652 inch 47.264 47.376 mm King Pin Diameter 1.8595 1.8600 inch 47.231 47.244 mm I-Beam Bore Diameter 1.8608 1.8622 inch 47.264 47.300 mm Torque Chart Location Tie Rod End Nut ( 1) Dia meter (Inches) ¾ 7/8 Size No. of Threads 16 14 ft-lbs. Torque N m Minimu m Maximu m Minimu m Maximu m Tie Rod Clamp Bolt 5/8 11 45 60 61 81 Steering Arm Nut and Tie Rod Arm Nut ( 1) King Pin Draw Key Nut ( 2) 1-1/8 1-1/4 12 12 80 120 450 775 105 160 650 1200 108 160 610 1050 143 218 881 1625 3/8 16 25 31 34 42 King Pin Cap Bolts 5/16 18 17 25 23 34 1: If cotter pin cannot be installed after minimum torque is attained, the nut must be advanced until the cotter pin can be installed. Torque specified is for taper and threads which are clean and oil free. 2: Torque to specifications. Tap unthreaded end of draw key sharply with a hammer, and re-torque draw key nut to specifications. 010-3
Special Tools Special service tools are available from: OTC Division, Service Tools, 655 Eisenhower Drive, Owatonna, MN 55060 Telephone: 1-800-533-0492 Fax Number: 1-800-283-8665 The following is a list of tools needed to service the front axles in this manual. These tool numbers are from OTC Tool Division. Dana makes no warranty or representation of these tools. M odels Serviced Description Tool Number Tools to service all axle models Tools to service axle models I-200SA/SG and I-146SA/SG Lubrication and Maintenance Schedule King Pin Bushing Basic Set Bushing Installer Seal Installer Lubrication Recommended Maintenance Schedule for On-Highway Use ZTSE 4330A ZTSE 4330-5A ZTSE 4330-55 Interval Co mponent Procedure 6,000 miles/monthly Wheel Bearings (Oil) Check level and fill with GL-5 gear lube as required 25,000 miles/6 month King Pins* and Tie Rod Ends Lube with NLGI-2 Lithium Grease EP-2 Moly Grease 30,000 miles/annually Wheel Bearings (Grease) Repack w/ngli-2 Lithium Grease EP-2 Moly Grease 100,000 miles/annually Wheel Bearings (Oil) Change Lubricant GL-5 Distribution of grease through the king pin bushing pockets may be enhanced by lifting weight off of front wheels during lubrication process. Recommended Maintenance Schedule for On/Off Highway Use (Low Mileage/High Hour Operation) Interval Co mponent Procedure 3,000 miles/monthly Wheel Bearings (Oil) Check level and fill with GL-5 gear lube as required 6,000 miles or every 6 mo. or 300 hrs. of operation 12,000 miles or annually or 600 hrs. of operation 24,000 miles or annually or 1000 hrs. of operation King Pins* and Tie Rod Ends Wheel Bearings (Grease) Wheel Bearings (Oil) Lube with NLGI-2 Lithium Grease EP-2 Moly Grease Repack w/ngli-2 Lithium Grease EP-2 Moly Grease Change Lubricant GL-5 010-4
Service Parts and Axle Identification Genuine Spicer Service Parts Should an axle assembly require replacement component parts, it is recommended that Spicer Heavy Axle Service Parts be used. Spicer Heavy Axle Service Parts are manufactured under the same rigid specification as are original equipment axle components. This assures the customer who uses genuine Spicer service parts maximum reliability for a Spicer Heavy Axle assembly. They may be obtained through your vehicle manufacturer. The use of non-original Spicer Service Parts may cause premature component failure and may void the warranty. The items included in this book are currently being offered as service parts at the time of printing. The part numbers and illustrations are provided specifically for reference purposes only. Therefore, Spicer reserves the right to update this manual without notice or liability. Figure 1 Model Identification Numbering System : All axle models with the SA designation are now designated as SG axles. 010-5
Front Axle Inspection Guidelines and Description Figure 2 Exploded View of Axle Steering Knuckle Assembly and Inspection Guidelines 010-6
Figure 3 Identification Tag Type and Location All front axles identified with either an aluminum or mylar tag located between the spring pads, on the front side of the center beam section. (See Figure 3) Precautions and King Pin Wear Limits The front axles covered in this section are I-beam type, non-driving units. Front axles are machined with different king pin angles to compensate for crowned road surfaces. The axle must be installed with the identification tag to the front of the vehicle. Some applications may also have the word front cast into the lower flange of the I-beam. Precautions Spicer strictly prohibits the modifying or reconditioning of any front non-driving axle component for any reason. Spicer recommends replacing any component which is damaged or out of specification. All of the major components are heat treated and therefore, cannot be bent, twisted, welded, heated or reconditioned without experiencing a strength and/or fatigue life reduction. Examples of specific prohibited operations are: 1. Hot or cold bending or twisting of I-beam, tie rod arms for any reason. 2. Welding of, or to, steering arms, tie rod arms, I- beams, steering knuckles, king pins or tie rod assemblies. 3. The re-drilling or re-boring of I-beam king pin holes for a bushing. Figure 4 Typical Steering Knuckle 4. Milling or machining of any component. 5. Spray welding of bearing diameters or other machined surfaces. 6. The re-drilling or re-boring of draw key holes. 7. Relocation or removal of tie rod clamps. 8. 010-7
Maximum Limits for King Pin This procedure is for determining if front axle king pin bushing wear (side play) and spindle vertical end play measurements exceed the maximum wear limits for normal service and decide if maintenance is necessary. King Pin Bushing Wear Check The simplest method for checking king pin looseness is to use a canber gauge in this particular operation are as follows: King pins and bushings must not have been recently lubricated before making this check. Measurements must be made before lubrication. 5. Push the wheel inward at the top and measure the movement obtained on the dial indicator at 17.5 inches (444.5 mm) radius mark on the tire. If more than 0.125 inch (3.175 mm) is obtained at the 17.5 inches (444.5 mm) mark, the king pin bushing should be replaced. Measure Spindle Vertical End Play 1. Block rear wheels. 2. Raise and support the axle. 3. Lift the wheel and tire (spindle only if wheel is removed) so that all clearance is taken up between the steering knuckle and axle pin boss. Figure 5 King Pin Bushing Wear Measurement 1. Block the rear wheels. 2. Raise and support axle on two jack stands. If the axle is supported on only one jack stand, a false reading will be obtained. 3. Apply brakes to eliminate wheel bearing play and to ensure a correct reading. Figure 6 Spindle Vertical End Play Check 4. Measure clearance using a feeler gauge as shown in Figure 6. If more than 0.060 inch (1.524 mm) is measured, add shims as needed to reduce clearance to 0.005 0.015 inch (0.1270 0.3810 mm). 4. Mark the tire at 17.5 inches (444.5 mm) radius from the center of the spindle. Position a dial indicator at 17.5 inches (444.5 mm) mark to measure tire movement. Accurate results depend upon measurement at specified radius. 010-8
King Pin Bushing Replacement Steering Knuckle Removal The following procedure applies to one knuckle, repeat the procedure for the remaining wheel end. All front axles use dual draw keys. I-120SG and I-146SG axles use dual threaded draw keys. All axles should be serviced with original draw key configuration. Block rear wheels. Raise the vehicle. Support vehicle on stands. Remove wheels as instructed. Remove the dirt shield screws and shields. On the models equipped with hydraulic disc brakes, calipers must be removed before hub. Support calipers so weight of caliper does not hang from hydraulic hose. Remove hubs on vehicle with disc brakes. Remove hub and drums on vehicles with drum brakes. Remove brake backing plate or caliper mounting bracket from the knuckle. It will be necessary to support drum brake backing plate so the weight of the backing plate is not on the air hose. Remove tie rod assembly and drag link from steering arms using a suitable tool. Remove draw key. Figure 8 Removing Steering Knuckle Cap Remove top and bottom steering knuckle caps. (See Figure 8). If there are O-rings under the caps, they must be removed. Figure 7 Removing Draw Key Staked draw keys: drive the staked draw key out at the opposite end of the staking using a drift and brass hammer. (See Figure 7) Threaded draw keys: remove nut and Belleville washers. Strike the threaded end of draw key with drift and brass hammer. Figure 9 Removing King Pin Drive out the king pin (Figure 9). Draw key must be removed prior to king pin removal. 010-9
Bushing Installation (Pre-sized Type) Do not heat axle to loosen king pin. Heat can weaken axle and cause excessive vehicle damage. Remove steering knuckles, thrust bearings and any spacer shims present. Thoroughly clean and inspect all parts. Kingpin Bushing Removal Select the appropriate service tool kit (pilots, remover and installer) for axle code number. All axles incorporate pre-sized bushings. Figure 11 Installing Pre-sized Bushings Assemble screw, support plate and installer with upper bushing as shown in Figure 11. Figure 10 Bushing Removal Assemble screw, support plate, and remover as shown in Figure 10. Tighten screw with wrench until bushing is removed from knuckle. Assemble tool at opposite end to remove remaining bushing. Important: Screw threads must be lubricated with high pressure lubricant. Clean and inspect knuckle prior to installation of new bushings. Replace if damaged. Figure 12 Bushing Seating Depth Tighten screw to pull bushing into knuckle. Install bushing to specified dimension as shown in Figure 12. Install lower bushing following the same procedure used in installing the upper bushing (except opposite end). 010-10
King Pin Seal Installation Installing Upper and Lower Seals There may be two styles of thrust bearings. One type is installed on thrust bearing with seal on top as shown in Figure 14. Figure 13 King Pin Bushing Seal Installation Position knuckle vertically to install top seal into bore. (See Figure 13) Hand start seal with sealing lip out or rounded edge into bore. (See Figure 13) Using adapter or steel plate, press seal into knuckle bore until it is flush with knuckle surface. Install bottom seal as outlined is steps 2 and 3. Steering Knuckle Installation Before installing king pins, lubricate inside of the bushings and outside of king pins with Fleetrite EP2 Moly Grease or equivalent NLGI No.2 multipurpose lithium grease to provide initial lubrication. Make certain that knuckle pin hole in axle center is clean and dry. Figure 14 Thrust Bearing Seal Installation Figure 15 Sealed Thrust Bearing The second style thrust bearing is a one piece design with seal lip installed towards the bottom of the knuckles as shown in Figure 15. Slide the thrust bearing between the lower face of axle center and lower steering knuckle yoke. Figure 16 Spindle Vertical End Play Check Align the steering knuckle yoke holes with axle and thrust bearing holes. Place a jack under the lower side of steering knuckle yoke and raise knuckle so that all clearance is taken up between lower yoke, thrust bearing and lower face of axle center end. See Figure 16. Check the clearance between the top face of upper axle center end and lower face of upper knuckle pin boss. Shims are available in various thickness to provide a desired clearance of 0.005 0.015 inch (0.1270 0.3810 mm). (See Figure 16) Lubricate the king pin at installation to assure initial lubrication of parts. 010-11
Install king pin from the top, taking care to align notch with draw key holes in I-beam. The machined flats are located closer to the top of the king pin to allow installation of the thrust bearing, while maintaining correct vertical position of king pin. The flats are also wider than the draw key allowing slight adjustment. The king pin must be vertically centered in the knuckle. This allows both top and bottom king pin end caps to be installed without interference. To make sure the king pins will accept lubricant, lubricate upper and lower king pin bushings through the cap grease fittings. If problems arise, you will not have to remove the brakes again to make repairs. Reinstall tie rod ends into the steering arms. Tighten the nuts to the specified torque. (Refer to Specifications, Torques, and Special Tools in this group). Then install the cotter pin. Reinstall brake components. Refer to Group 030.2 (Remove and Replace Hub and Rotor Assembly.). Clean and inspect the front wheel bearings. Refer to Group 030.2 Wheel End Components (Wheel Bearing Inspection). Install the bearings in the hub assembly using new seals. Refer to Group 030.2 (Remove and Replace Hub and Rotor Assembly.). Assemble hub and bearings on spindle. Remove and replace hub and rotor assembly. Install wheel rims and tires. Remove vehicle from floor stands. Check toe in by following original equipment manufacturer s guidelines for correct toe in adjustment. Figure 17 Draw Key Installation to Front of Axle Install draw keys. Threaded draw keys will replace staked draw keys as follows: Install top draw key with the threaded end of key to front of axle as shown in Figure 17. To seat the draw key, strike unthreaded end of key with the drift and a hammer. Install Belleville washers as shown in Figure 17. Install nut and tighten to specified torque. (Refer to Specifications, Torques, and Special Tools in this group). Install bottom draw key with threaded end to rear of axle. Repeat steps B,C, and D to finish installation of bottom draw key. Install king pin caps and O-ring. (See Figure 17) Tighten cap screws to specified torque. (Refer to Specifications, Torques, and Special Tools in this group). Steering Knuckle Stop Adjustment The steering arm stop screw should be adjusted to permit maximum turning angle. With power steering, the stop screw should be adjusted to assure that the power steering unit will not override the axle stop. Figure 18 Steering Stop Adjustment To prevent overriding, adjust power steering systems and stop screws so that the power is cut off before contact with the axle stop screw. (See Figure 18) 010-12
Adjust the axle steering stops to contact when the maximum turning angle of the specific axle is reached, and lock with jam nut. Adjust the power steering unit to stop ½ to 1 before axle steering stops contact (maximum turning angle). Maximum turn angle specifications to be checked at the inside wheel. The adjustment of both axle steering stops and power steering unit should be periodically checked and corrected if necessary. For more detailed instructions pertaining to wheel stop adjustment, follow the original equipment manufacturer s guidelines for turning angles and front wheel alignment. Tie Rod Inspection and Replacement Prior to performing a front wheel alignment, verify rear axle alignment in Group 020 (Rear Axle Alignment). Fittings are provided for periodic lubrication on some types of rod ends. Where no fittings are used, the tie rods have been lubricated at assembly and no further lubrication is necessary. If the tie rod taper joint is loose or the cotter pin is missing, remove, inspect and replace the tie rod arm/tie rod end if the contact surfaces are worn. Replacement Criteria Inspection Carefully wipe seal clean and examine for splits or tears that allow contaminants into the socket. If seal is acceptable, shake tie rod assembly by hand only. Prying on steering linkage can result in damage, creating false indication of looseness. Figure 20 Set Up Dial Indicator If looseness is detected, set up a dial indicator as shown in Figure 20. Jack up that side of the axle and measure movement at the tie rod end. Move the tire in and out as illustrated in Figure 20. Figure 19 Typical Tie Rod The tie rods are of a three piece construction, consisting of a tie rod and two rod end assemblies. The ends are threaded to the rod and locked with clamp bolts. (See Figure 19) Right and left hand threads are provided for toe in adjustment. Tension on ball stud in the rod ends is self adjusting and requires no attention in service other than periodic inspection to see that ball studs are tight in steering knuckle arms. C-clamp setup is recommended for testing the tie rod end for looseness. The tie rod end should be replaced if a reading of 0.030 inch or more is taken. Replace tie rod end at the next service interval. 010-13
We do not recommend removing the tapered stud from the arm to check rotating torque. This may damage the seal or socket assembly. The full boot clamped seal can give false rotational torque reading. At assembly, insure that the slotted nut is tightened according to specifications. (Refer to Specifications, Torques, and Special Tools in this group). If the cotter pin cannot be installed, tighten nut to the next slot. Do not back off once minimum torque is reached. When tie rod linkage ends are replaced, they must be threaded into the tie rod or drag link sufficiently to allow positioning of the clamp over the threads if not welded on the ball joint end. Position clamp bolt so it crosses the slot in rod end. Remove Tie Rod Assembly and Tie Rod Steering Arm This procedure includes removing the tie rod ends from tie rod. Refer to the precautions in this section. Remove the cotter pins and the nuts which secure each tie rod to the tie rod arm. Figure 21 Separate Rod End from Rod Arm Separate tie rod assembly from the tie rod arms, using a tie rod separator tool. (See Figure 21) Remove the cotter pin and the nut that fastens the tie rod arms in the knuckle. Remove the tie rod arms from the knuckle. If necessary, tap on the end of the rod with the stud nut assembled loosely on the stud (to avoid damage to the threads) using a brass drift and hammer. Remove the key. If necessary, use the following procedure to remove the tie rod ends from the rods. Mark the position of each tie rod end in the tie rod tube. Remove the clamp bolts and nut from the clamp on the tie rod. Thread the tie rod ends out of the tube rod. Install Tie Rod Steering Arm and Tie Rod Assembly This procedure includes installing the tie rod ends to the tie rod. Press the key in the slot in the steering arm. Install the tie rod arm in the knuckle. 010-14
Install the nut on the tie rod arm. Tighten to the specified value. (Refer to Specifications, Torques, and Special Tools in this group). Install the cotter pins. If necessary, tighten the nut until the holes are aligned. Do not loosen the nut to install the cotter pin. If the cotter pin can not be installed, tighten nut to the next stop. The tie rod has right hand threads on one end and left hand threads on the other end. Make sure the ends are installed properly on the tube. Figure 22 Proper Indexing of Tie Rods Proper indexing, or alignment of tie rod ends, (left tie rod end parallel to right tie rod end) will eliminate restricted movement of the tie rod assembly. This restriction could cause premature failure of tie rod end. (See Figure 22). Toe in should be checked and adjusted to vehicle specifications if necessary. Figure 23 Types of Tie Rod Clamps When tie rod ends are replaced or toe in is adjusted, both ends must be threaded into the tie rod tube far enough to completely cover the slots in the tube. (See Figure 23) If removed, install the tie rod ends on the tie rod to the position marked during removal. If new tie rod ends are installed, thread the ends equally on the cross tube to the required length. Refer to CAUTION in tie rod text. Install the nuts and the bolts in the clamps. Tighten to the specified value. (Refer to Specifications, Torques, and Special Tools in this group). Assemble the tie rod ends into the tie rod steering arms. Install the tie rod stud nuts. Tighten to specified value. (Refer to Specifications, Torques, and Special Tools in this group). Install the cotter pins. If necessary, tighten the nut until the holes are aligned. Do not loosen the nut to install the cotter pin. Lubricate tie rod ends. Check toe in by following original equipment manufacturer s guidelines for correct toe in adjustment. Some tie rod clamps will be free to rotate around the tie rod allowing setting of toe in while avoiding contact of the axle. There are two ways mechanical stops will position the clamps. One style of clamp is limited by a spot weld on the tube. The second style of clamp is limited by a tab that will lock against the end of the tube. Refer to Figure 23. 010-15
Wheel Bearing Adjustment Adjust wheel bearings by original equipment manufacturer maintenance schedules or after any unscheduled maintenance that requires disturbing proper adjustment of the wheel bearings. Check bearing adjustment with a dial indicator and a magnetic base. Make sure dial indicator is oriented parallel to the vehicle axle. Bearing endplay should not exceed 0.010 inch (0.25 mm). When bearing adjustment is correct, the hub should rotate freely without excess play. If hub binds or shows excessive endplay, repeat procedure. After the hub and bearings are assembled in place on the spindle, install the retaining washer and adjusting nut. Tighten the wheel bearing adjusting nut to 120 140 ft-lb (163 190 N m). While rotating hub to seat bearing, loosen adjusting nut ½ turn. Tighten adjusting nut again to 50 ft-lb (68 N m). While rotating the hub loosen the nut ¼ turn. Front Axle Wheel Alignment and Balance Hendrickson Axles Spring Suspension TCFE 3+/-1 Degree Positive 0 Degree ± 7/16 Degree 0 Degree ± 7/16 Degree 0 to 1/16 Inch Hendrickson Air Suspension TCFE TCRE 3+/-1 Degree Positive 0 Degree ± 7/16 Degree 0 Degree ± 7/16 Degree 0 to 1/16 Inch TC Series Front Axle Wheel Alignment and Balance Back to Top 010-16