INSTALLATION INSTRUCTION 88073 Rev C FOR RANCHO SUSPENSION SYSTEMS RS6572 & RS6573: DODGE RAM READ ALL INSTRUCTIONS THOROUGHLY FROM START TO FINISH BEFORE BEGINNING INSTALLATION IMPORTANT NOTES! WARNING: This suspension system will enhance the off-road performance of your vehicle. It will handle differently, both on and off-road, from a factory equipped passenger car or truck. Failure to drive this vehicle safely may result in serious injury or death to the driver and passengers. ALWAYS WEAR your seat belts, REDUCE your speed, and AVOID sharp turns and other abrupt maneuvers. A. Before installing this system, have the vehicle s alignment and frame checked by a certified technician. The alignment must be within factory specifications and the frame of the vehicle must be sound (no cracks, damage or corrosion). B. Do not install a body lift kit with this suspension system or interchange Rancho components with parts from another manufacturer. Use Rancho shock absorber RS999283 or RS5283 on the front and Rancho shock absorber RS999297 or RS5297 on the rear. C. Do not powdercoat, chrome, cadmium, or zinc plate any of the components in this system. Doing so will render the warranty null and void. To change the appearance of components, enamel paint can be applied over the original coating. D. Each hardware kit in this system contains fasteners of high strength and specific size. Do not mix hardware kits or substitute a fastener of lesser strength. See bolt identification table on page 2. E. Compare the contents of this system with the parts list in these instructions. If any parts are missing, contact the Rancho Technical Department at 1-734-384-7804. F. Install all nuts and bolts with a flat washer. When both SAE (small OD) and USS (large OD) washers are used in a fastener assembly, place the USS washer against the slotted hole and the SAE washer against the round hole. G. Apply a drop of thread locking compound to all bolts during installation. CAUTION: Thread locking compound may irritate sensitive skin. Read warning label on container before use.
H. Unless otherwise specified, tighten all nuts and bolts to the standard torque specifications shown in the table below. USE A TORQUE WRENCH for accurate measurements. I. Some of the service procedures require the use of special tools designed for specific procedures. The following tools and supplies are recommended for proper installation of this system: Dodge Service Manual Torsion Bar Unloading Tool 8686 Puller 8677 Strap Wrench Dot 3 Brake Fluid Drill motor Hacksaw Assorted Drills: 1/8" through 1/2" Torque Wrench (250 FT-LB capacity) 1/2 Drive Ratchet and Sockets Assorted Combination Wrenches Heavy Duty Jack Stands Wheel Chocks (wooden blocks) Hydraulic Floor Jack Center punch File Hammer Wire Brush (to clean bracket mounting surfaces) Silicone Spray Lubricant Tape Measure Safety Glasses (wear safety glasses at all times) J. It is extremely important to replace torsion bars, CV flanges, and front drive shaft/pinion relationships as original. Be sure to mark left/right, front/rear, and indexing of mating parts before disassembly. A paint marker or light colored nail polish is handy for this. K. Suspension components that use rubber or urethane bushings should be tightened with the vehicle at normal ride height. This will prevent premature failure of the bushing and maintain ride comfort. the beginning of each step when you finish it. Then when you stop during the installation, it will be easier to find where you need to continue from. M. This suspension system was developed using the following wheel & tire combination: 17" x 8.5" wheel with 5 inches of backspacing and a 35" x 12.5" tire. Before installing any other combination, consult your local tire and wheel specialist. N. Important information for the end user is contained in the consumer/installer information pack. If you are installing this system for someone else, place the information pack on the driver s seat. Please include the installation instructions when you finish. O. Thank you for purchasing the best suspension system available. For the best-installed system, follow these instructions. If you do not have the tools or are unsure of your abilities, have this system installed by a certified technician. RANCHO SUSPENSION IS NOT RESPONSIBLE FOR DAMAGE OR FAILURE RESULTING FROM AN IMPROPER OR MODIFIED INSTALLATION L. The required installation time for this system is approximately 5 to 6 hours. Check off the box ( ) at STANDARD BOLT TORQUE & IDENTIFICATION INCH SYSTEM METRIC SYSTEM Bolt Size Grade 5 Grade 8 Bolt Size Class 9.8 Class 10.9 Class 12.9 5/16 15 FT-LB 20 FT-LB M6 5 FT-LB 9 FT-LB 12 FT-LB 3/8 30 FT-LB 35 FT-LB M8 18 FT-LB 23 FT-LB 27 FT-LB 7/16 45 FT-LB 60 FT-LB M10 32 FT-LB 45 FT-LB 50 FT-LB 1/2 65 FT-LB 90 FT-LB M12 55 FT-LB 75 FT-LB 90 FT-LB 9/16 95 FT-LB 130 FT-LB M14 85 FT-LB 120 FT-LB 145 FT-LB 5/8 135 FT-LB 175 FT-LB M16 130 FT-LB 165FT-LB 210 FT-LB 3/4 185 FT-LB 280 FT-LB M18 170 FT-LB 240FT-LB 290 FT-LB 2
PARTS LIST P/N DESCRIPTION QTY. 1431 Bump Stop 2 15140 Riser Block 2 170085 Brake Hose, Left 1 170086 Brake Hose, Right 1 176149 Aft Brace Bracket 2 176152 Rear Bump Stop Bracket 2 176230 Knuckle, Left 1 176231 Knuckle, Right 1 176233 Front Bump Stop Spacer 2 176234 Subframe 1 176237 Aft Brace 2 176238 Axle Tube Drop Bracket, Front Half 1 176239 Axle Tube Drop Bracket, Back Half 1 176240 Differential Drop Bracket, Left Half 1 176241 Differential Drop Bracket, Right Half 1 176242 Differential Drop Bracket, Aft 1 176244 T Bar Crossmember Drop Bracket 2 602614 Tie Rod End 2 740022 9/16-18 x 4.16 x 9.75 U-bolt 4 860086 Brake Hose Gasket Kit 1 Copper Washer 4 860152 U-bolt Hardware Kit 1 9/16-18 Nyloc Nut 8 9/16 USS Washer 8 860406 Rear Bump Stop Hardware Kit 1 420051 Sleeve 4 M10-1.5 x 70 4 M10 Lock Washer 4 860407 Riser Block Pin Kit 1.625 x.775 Pin 2 860450 Subframe Hardware Kit 1 M16-2.0 x 130 HHCS 2 M16-2.0 Stover Nut 2 M16 Washer 4 Thread Lock 3 860451 End Link Hardware Kit 1 420044 Sleeve 2 3/8-16 x 15.0 HHCS 2 3/8-16 Nyloc Nut 2 Retainer 8 Grommet 8 860452 Axle Tube Hardware Kit 1 M12-1.75 x 65 HHCS 2 P/N DESCRIPTION QTY. M12-1.75 x 70 HHCS 2 M12-1.75 Stover Nut 4 M12 Washer 8 860453 Differential Drop Hardware Kit 1 M12-1.75 x 60 HHCS 2 M12 1.75 x 65 HHCS 2 M12-1.75 Stover Nut 4 M12 Washer 8 860454 Differential Drop Hardware Kit, Aft 1 420045 Sleeve 2 M12-1.75 x 60 HHCS 4 M12-1.75 Stover Nut 4 M12 Washer 8 860455 Aft Brace Hardware Kit 1 457 Sleeve 4 553 Bushing 8 9/16-12 x 4.0 HHCS 4 9/16-12 Stover Nut 4 9/16 SAE Washer 8 860456 Torsion Bar Hardware Kit 1 M12-1.75 x 90 HHCS 4 M12-1.75 Stover Nut 4 M12 Washer 8 3/8-16 x 1.0 HHTS 4 860457 OE Skid Plate Hardware Kit 1 45365 Bushing 2 3/8-16 x 1.25 HHCS 4 3/8-16 Stover Nut 4 3/8 SAE Washer 10 M8-1.25 x 40 HHCS 2 3/8-16 x 1.0 HHTS 4 860459 Tie Rod Hardware Kit 1 M18-1.5 Jam Nut 2 860460 Hub Spacer Kit 1 176232 Axle Hub Spacer 2 860461 Front Bump Stop Hardware Kit 1 3/8-16 x 1.25 HHCS 2 3/8 SAE Washer 2 Thread Lock 2 94180 Information Pack 1 780281 Rancho Decal 1 88073 Instructions 1 94119 Consumer/Warranty Information 1 94177 Warning Sticker 1 3
ITEM NO. PART NO. DESCRIPTION QUANTITY 1 1431 Bump Stop 2 2 15140 Riser Block 2 3 170085 Brake Hose, Left 1 4 170086 Brake Hose, Right 1 5 176149 Aft Brace Bracket 2 6 176152 Rear Bump Stop Bracket 2 7 176230 Knuckle, Left 1 8 176231 Knuckle, Right 1 9 176233 Front Bump Stop Spacer 2 10 176234 Subframe 1 11 176237 Subframe Aft Brace 2 12 176238 Axle Tube Drop Bracket, Front Half 1 13 176239 Axle Tube Drop Bracket, Back Half 1 14 176240 Differential Drop Bracket, Left Half 1 15 176241 Differential Drop Bracket, Right Half 1 16 176242 Differential Drop Bracket, Aft 1 17 176244 T Bar Crossmember Drop Bracket 2 18 602614 Tie Rod End 2 19 740022 9/16-18 x 4.16 x 9.75 U-bolt 4 4
VEHICLE PREPARATION FRONT SUSPENSION 2) Support the transfer case skid plate and remove the bolts. See Illustration 3. Remove the skid plate. 1) Park the vehicle on a level surface. Set the parking brake and chock rear wheels. Measure and record the distance from the center of each wheel to the top of the fender opening. See illustration 1. Illustration 1 2) Loosen the front lug and hub nuts before raising the vehicle. 3) Raise the front of the vehicle and support the frame with jackstands. Remove the front wheels and set them aside. SKID PLATE REMOVAL (IF APPLICABLE) 1) Remove the bolts holding the differential skid plate to the front crossmember. See Illustration 2. Slide the skid plate back and remove. TORSION BAR REMOVAL Illustration 3 1) Mark the torsion bars left and right. Make alignment marks on the torsion bars, the lower control arms, and the anchors. 2) Measure and record the length of the exposed threads on the torsion bar adjustment bolts. Left: Right: 3) Install the torsion bar unloading tool (8686). See illustration 4. Increase the tension on the torsion bar until the load is removed from the adjustment bolt. Illustration 2 Illustration 4 5
4) Remove the adjusting bolt and swivel nut. See illustration 5. Relieve the tension on the torsion bar and remove the tool. Illustration 7 Illustration 5 5) Remove the torsion bar from the lower control arm. 6) Repeat steps 3 through 5 for the other side. 6) Remove the nuts at the upper and lower ball joints. Disconnect the ball joints from the steering knuckle using puller 8677. Remove the steering knuckle. 7) Remove the lower control arm pivot bolts. See illustration 8. Remove the lower control arm. STEERING KNUCKLE & LOWER CONTROL ARM REMOVAL 1) Remove the brake caliper and its mounting bracket as an assembly. Hang the caliper assembly with wire or a tie wrap. 2) Mark the brake rotor left or right. Remove the brake rotor. If applicable, remove the ABS speed sensor from the hub. 3) Remove the axle shaft hub nut. 4) Remove the nut from the outer tie rod stud. Disconnect the tie rod end from the steering knuckle with puller 8677. See illustration 6. Illustration 8 8) Repeat steps 1 through 7 for the other side. SUBFRAME INSTALLATION 1) Remove the crossmember that connects the rear frame brackets of the lower control arms. 2) To provide clearance for the differential, cut 1/4" off the inside front corner of the driver side frame bracket. See Illustration 9. Illustration 6 3) With an assistant s help, raise the subframe (176234) up into the lower control arm frame brackets. 5) Remove the front shock absorber and stabilizer link. See illustration 7 6
Illustration 9 4) Attach the front of the subframe with the original pivot bolts. Attach the rear of the subframe with the original crossmember bolts. See illustration 10. Tighten the front bolts to 150 ft. lbs and the rear bolts to 75 ft. lbs. Illustration 11 5) Using the hardware from kit 860453, loosely attach differential drop brackets 176240 (left half) and 176241 (right half) to the differential upper mount and frame bracket. See illustrations 12 and 13. Use the longer bolts on the bottom. Illustration 10 Illustration 12 FRONT DIFFERENTIAL DROP BRACKET INSTALLATION 1) Support the front differential assembly with a jack. 2) Remove the differential housing rear mounting bolts. See illustration 11. 3) Remove the right axle tube mounting bolts. 4) Remove the differential housing upper mounting bolts. Carefully lower the differential assembly about 4 inches. Illustration 13 7
6) Using the hardware and sleeves from kit 860454, loosely attach drop bracket 176242 to the differential rear mount and frame bracket. See illustration 13. 7) Loosely attach axle tube drop brackets 176238 and 176239 with the hardware from kit 860452. See illustration 14. The wider end of each bracket is attached to the top with the shorter bolts. LOWER CONTROL ARM & STEERING KNUCKLE INSTALLATION 1) Insert the left lower control arm into the subframe pockets on the driver side. Attach the front of the control arm with the hardware from kit 860450. Attach the rear of the control arm with the original nut and bolt. NOTE: Do not tighten pivot bolts until vehicle is at normal ride height. 2) Remove the three hub mounting bolts from the driver side steering knuckle. Separate the hub, dust shield and ABS clip (if applicable), from the knuckle. See illustration 16. Illustration 14 8) Tighten all mounting bolts to 70 ft. lbs. 9) Check the clearance between the front drive shaft and the exhaust crossover pipe. See illustration 15. Illustration 16 3) Attach dust shield, hub and ABS clip to new left knuckle 176230. Tighten hub bolts to 120 ft. lbs. NOTE: If equipped with ABS brakes, position the speed sensor opening on the hub toward the front of the vehicle. 4) Install axle hub spacer 176232 on the driver side axle shaft. See illustration 17. Illustration 15 NOTE: To provide clearance on vehicles equipped with the 5.9-liter engine, the crossover pipe must be reshaped slightly. If you do not have a torch or are unsure of your abilities, remove drive shaft and take vehicle to an exhaust repair shop. If you have the capability, separate drive shaft from differential, heat pipe at the contact point, dimple pipe and reattach drive shaft. 8 Illustration 17
5) Support the lower control arm with a jack. Insert axle shaft through hub and install steering knuckle assembly onto the lower ball joint. Install ball joint nut. CAUTION: The ball joint stud taper must be clean and dry before installing into the knuckle. 6) Install the upper ball joint into the knuckle. Install ball joint nut. 7) Tighten the upper ball joint nut to 55 ft. lbs. Tighten the lower ball joint nut to 60 ft. lbs. 8) Raise and support the lower control arm until the spindle to fender height is 26 inches. Tighten the lower control arm pivot bolts to 150 ft. lbs. 9) Attach the stabilizer bar to the lower control arm with end link kit 860451. See illustration 18. Illustration 19 2) Cut 1/2 off the end of the tie rod. Remove the jam nut. If necessary, file end of tie rod to remove burrs and clean threads. NOTE: To properly adjust the toe, 3/16 additional tie rod trimming may be necessary on some vehicles. 3) Thread new jam nut from kit 860459 then outer tie rod end 602614 onto the tie rod. 4) Attach the tie rod end to the steering knuckle with the original nut. Tighten the ball stud nut to 55 ft. lbs. 5) Finger tighten jam nut. Turn the tie rod until three threads are exposed beyond the jam nut. Tighten jam nut to 55 ft. lbs. 6) Repeat steps 1 through 5 for the other side. Illustration 18 10) Install new Rancho shock absorber. 11) Install the axle shaft hub nut and tighten to 185 ft. lbs. 12) Repeat steps 1 through 11 to install the right lower control arm and steering knuckle on the passenger side. TIE ROD END REPLACEMENT 1) Loosen the jam nut on the tie rod assembly. Remove the outer tie rod end. See illustration 19. BRAKE HOSE REPLACEMENT 1) Install the brake rotor. Attach the front caliper to the steering knuckle with the original mounting bolts. Tighten the caliper mounting bolts to 130 ft. lbs. 2) Separate the passenger side front brake line from the brake hose. Plug brake line to prevent brake fluid seepage. NOTE: If the master cylinder becomes empty, then the entire brake system must be bled. Follow manufacturer s recommendations for bleeding the entire system. 3) Remove the bolts holding the brake hose to the frame and caliper. If applicable, separate the ABS wire from the brake hose. See illustration 20. 9
3) Apply thread lock and attach the bump stop assembly to the frame bracket with the hardware from kit 860461. See illustration 21. To tighten, hold the bolt and turn the spacer with a strap wrench. Illustration 20 4) Remove the brake hose. 5) Attach new right brake hose 170086 to the frame. Tighten the frame bolt to 7.5 ft. lbs. 6) Attach the brake line to the hose. Tighten the brake line fitting to 14 ft. lbs. 7) Attach the brake hose to the caliper with the new washers from kit 860086. Hold the hose to keep it from moving and tighten the bolt to 20 ft. lbs. 8) Repeat steps 1 through 7 to install left brake hose 170085 on the driver side. Illustration 21 AFT BRACE ASSEMBLY & INSTALLATION 1) Lubricate two bushings (553) and one sleeve (457), from kit 860455, with a silicon spray. Press the bushings and sleeve into aft brace 176237. See illustration 22. NOTE: If your vehicle does not have ABS brakes, remove the 10mm plug from left brake hose 170085. 9) Bleed the front brakes as follows: Fill master cylinder reservoir with approved brake fluid. Attach a clear hose to bleeder valve of right front caliper. Immerse other end of hose into glass container partially filled with brake fluid. Open bleeder valve, then have a helper press down on the brake pedal. Close bleeder valve and repeat process until fluid is clear and free of bubbles. Repeat steps for left front caliper. FRONT BUMP STOP & SPACER INSTALLATION CAUTION: Ball joint failure may occur if the new bump stop and spacer are not installed. 1) Pry the original bump stop from the frame bracket below the upper control arm. 2) Apply thread lock and attach new bump stop 1431 to spacer 176233. Tighten by hand. 10 Illustration 22 2) Repeat step 1 to install the remaining bushings and sleeves. 3) Loosely attach the angled end of each aft brace assembly to the rear of the subframe (176234) with the hardware from kit 860455. Refer to illustration 21. The aft braces should point slightly outward. 4) Remove the inside nut and bolt from each side of the transmission crossmember. See illustration 23.
Illustration 23 5) Using the hardware removed in the previous step, loosely attach the aft brace brackets (176149) to the front of the transmission crossmember. Insert the bolt from the front. See illustration 24. Illustration 25 4) Attach drop bracket 176244 to the original bracket with the 12mm hardware from kit 860456. 5) Attach drop bracket 176244 to the bottom of the frame rail with the original screws (if applicable) or the self-tapping screws from hardware kit 860456. Tighten the 12mm bolts to 75 ft. lbs and the selftapping screws to 30 ft. lbs. 6) Align marks and insert the torsion bar into its respective lower control arm and anchor. Place the anchor in the crossmember. 7) Install the torsion bar loading/unloading tool (8686). Refer back to illustration 4. Increase the tension on the anchor. Illustration 24 6) Attach the aft braces to the brackets with the hardware from kit 860455. Tighten the aft brace mounting bolts then the bracket to crossmember bolts to 75 FT-LBS. 8) Reinstall the swivel nut and adjusting bolt. Thread the adjusting bolt in until 1.2 inches of threads are exposed below the swivel nut. Refer back to step 2 of Torsion Bar Removal. Remove the loading/unloading tool. 9) Repeat steps 2 through 8 for other side. TORSION BAR & DROP BRACKET INSTALLATION 1) Remove the mounting bolts from the torsion bar crossmember. Remove the crossmember. 2) If your vehicle did not have a skid plate installed, enlarge the skid plate mounting holes to 5/16. 3) Place torsion bar drop bracket 176244 against the bottom of the frame rail and insert it into the original crossmember bracket. See illustration 25. SKID PLATE INSTALLATION (IF APPLICABLE) 1) Attach the rear of the transfer case skid plate to drop brackets 176244 with the 3/8 hardware from kit 860457. 2) Insert the bushings from kit 860457 between the skid plate and the transfer case crossmember. See illustration 26. Attach the front of the skid plate to the crossmember with the 8mm bolts from kit 860457. 11
9) Install front wheels and lower vehicle to ground. Tighten the lug nuts to 140 ft. lbs. RISER BLOCK INSTALLATION REAR SUSPENSION 1) Chock front wheels. Raise the rear of the vehicle and support the frame with jack stands. Remove the rear wheels. 2) Support the rear axle assembly with a floor jack. Remove both rear shock absorbers. See illustration 28. Do not reuse OEM shock absorbers with this suspension system. Illustration 26 3) With the axle still being supported, remove the U-bolts on the passenger side only. See illustration 28. 3) Tighten all skid plate bolts to 25 ft. lbs. 4) Cut off the raised section on top of the front differential skid plate. See illustration 27. Drill two 3/8 holes as shown in the illustration. Illustration 28 4) Carefully lower the axle about four inches. Do not allow the axle to hang by any hoses or cables. Illustration 27 5) Insert a block pin from kit 860407 into the hole in the axle pad. Place the new riser block (15140) on the axle pad. See illustration 29. 5) Place the skid plate against the subframe below the front differential. Push the skid plate back so the upward curve contacts the front of the subframe crossmember. 6) Using the skid plate as a template, mark the mounting hole locations on the bottom of the subframe crossmembers. 7) Remove skid plate and drill a 5/16 hole at each of the marked locations. 8) Attach skid plate to subframe with the selftapping screws from kit 860457. Tighten screws to 25 ft. lbs. Illustration 29 12
6) Raise the axle assembly until the riser block contacts the helper spring. Be sure to align the hole in the block with the head of the center bolt. 7) Attach the spring to the axle with the NEW U- bolts (740022) and hardware from kit 860152. Snug the nuts down but do not tighten. 8) Repeat steps 3 through 7 for the driver side. 9) Install new Rancho shock absorbers BUMP STOP BRACKET INSTALLATION 1) Remove the bump stop from the frame rail above the rear axle. See illustration 30. 4) Install rear wheels and lower vehicle to ground. Tighten lug nuts to 140 ft. lbs. 5) Tighten the U-bolt nuts evenly to 110 ft. lbs. FINAL CHECKS & ADJUSTMENTS 1) Jounce suspension and move the vehicle to normalize ride height. Verify that the front spindle to fender height is 26" and that both sides are equal. If necessary, reinstall tool 8686 and adjust the tension on the torsion bars to correct the height. NOTE: Some vehicles (when driven in 4wd) may experience a slight vibration if the spindle to fender height is set at or above 26". To remove an undesirable vibration, it may be necessary to lower the height to 25". 2) Turn the front wheels completely left then right. Verify adequate tire, wheel, and brake hose clearance. Inspect steering and suspension for tightness and proper operation. 3) With the suspension at maximum extension (full droop), inspect and rotate all axles and drive shafts. Check for binding and proper slip yoke insertion. The slip yoke should be inserted a minimum of one inch into the transfer case and/or transmission. Illustration 30 2) Attach bump stop spacer 176136 and the original bump stop to the frame rail with the hardware and sleeves from kit 860406. See illustration 31. Tighten the bolts to 45 ft. lbs. 4) Ensure that the vehicle brake system operates correctly. If new brake hoses were installed, verify that each hose allows for full suspension movement. 5) Readjust headlamps. Have vehicle aligned at a certified alignment facility. Recommended Alignment Specifications Caster (degrees): 4.4! 1.0 Camber (degrees): 0 -.3 Sum Toe In (degrees):.1!.1 Please retain this publication for future reference. See Important Note N. Illustration 31 3) Repeat steps 1 and 2 for the other side. 13