Freightliner irliner Suspension 3.05 Ride Height djustment NOTICE Failure to adjust the suspension ride height could adversely affect driveline angles. lso, if the air springs are set too high, the driver may have difficulty (or be prevented from) backing the vehicle under a trailer. If the air springs are set too low, rapid wear of suspension parts will result. The height-control valve make and installation may vary. Use the applicable procedure to adjust the suspension height. Vehicle with a arksdale Valve Vehicle with a Meritor WCO Valve djustable Installation Vehicle with a Meritor WCO Valve Fixed Installation The arksdale height-control valve replaced the Meritor WCO valve after July 5, 997. On vehicles with tandem-axle irliner rear suspensions, the arksdale vertical linkage rod is attached to the forward drive axle instead of the rearmost drive axle, and the valve is mounted on the frame rail; see Fig.. There are two types of WCO height-control valve installations: adjustable and fixed. See Fig.. On adjustable installations, the suspension height is changed by tilting the height-control valve up or down. On fixed installations, the suspension height is changed by adjusting the length of the vertical linkage rod. Vehicle with a arksdale Valve IMPORTNT: efore checking the suspension height, make sure there is no load on the chassis. For tractors, unhitch the trailer. Trucks must be empty.. Park the vehicle on a level surface, using a light application of the Do not apply the parking Put the transmission in neutral. uild the secondary air pressure to at least 00 psi (690 kpa). Shut down the engine.. Mark the location of the front and rear tires on the floor, then chock the tires on one axle only. 08/5/97. Forward Drive xle. Valve Mounting racket 3. Height-Control Valve 4. Neutral-Position Hole 6 7 5 f30558 NOTE: The stud bolt that fastens the horizontal control lever to the vertical is oriented correctly when the linkage rod is vertical as viewed from the side of the vehicle; see Fig. 3. 3. Measure the distance between the left forward most axle stop and the suspension as indicated. See Suspension Ride Height Measurement, Table, Table, Table 3, Table 4, and Table 5 for an acceptable range of heights for each suspension. IMPORTNT: Suspensions with Dual-Leaf Springs, and all Vehicles built before ugust 4, 00: Measure between the top of the U-bolt and the bottom of the axle stop (distance ). Suspensions with Single-Leaf Springs, built after ugust 4, 00: Measure between the top of the U-bolt pad and the bottom of the axle stop (distance ). 4. If the distance is within the acceptable range, the ride height is adjusted correctly. pply the parking 4 3 5. Horizontal Control Lever 6. Stud olt 7. Vertical Linkage Rod Fig., arksdale Height-Control Valve Installation Heavy-Duty Trucks Service Manual, Supplement 38, July 009 0/
3.05 Freightliner irliner Suspension If the measurement is not within the acceptable range, go to the next step. 5. While holding the height-control valve mounting studs in place with an llen wrench, loosen the nuts that attach the valve to the mounting bracket. /0/005 f30838b Measure Point = Measure Here Suspension Height Measurement () Min Target Max -3/8 inch (60 mm) -5/8 inch (67 mm) -7/8 inch (73 mm) Table, Suspension Ride Height Measurement, Dual- Leaf Spring, 0k/40k High Ride NOTICE When loosening a arksdale height-control valve from a mounting bracket, always hold the valveside mounting studs in place with an llen wrench while loosening or tightening the nuts that attach the valve to the bracket. ecause the mounting studs are threaded into the valve body, loosening the nuts without holding the studs can tighten the studs, which can crush the valve body and damage the valve. Conversely, tightening the nuts without holding the studs can back the studs out, causing a separation of the two halves of the valve body, and possibly a leak. 09/8/005 Measure Point = Measure Here f3046a Suspension Height Measurement () Min Target Max -3/4 inch (70 mm) 3 inch (76 mm) 3-/4 inch (83 mm) Table, Suspension Ride Height Measurement, Dual- Leaf Spring, 3k/46k/69k High Ride 6. djust the position of the valve body, until the distance from the bottom of the left axle stop to the top of the U-bolt or U-bolt pad is the target measurement from the applicable Suspension Ride Height Measurement table. 7. Center the horizontal control lever on the valve by inserting a 5/3-inch (4-mm) pin or drill bit into the neutral-position hole in the height-control valve and the horizontal control lever. 0/ Heavy-Duty Trucks Service Manual, Supplement 38, July 009
Freightliner irliner Suspension 3.05 09/7/005 f30933a Measure Point Suspension Height Measurement ( or ) Min Target Max = Measure Here if uilt efore ugust 4, 00 = Measure Here if uilt fter ugust 4, 00-3/8 inch (60 mm) -5/8 inch (67 mm) -7/8 inch (73 mm) Table 3, Suspension Ride Height Measurement, Single-Leaf Spring, 0k/40k, High Ride Height 8. While holding the height-control valve mounting studs in place with an llen wrench, tighten the nuts 95 lbf in (00 N cm). Do not overtighten. 9. Remove the pin or drill bit previously inserted in the height-control valve. 0. Drive the vehicle unloaded for about /4 mile (/ km), then stop the vehicle in the exact location (as previously marked) of the original measurement. Park the vehicle using a light brake application. Chock the tires on one axle only, and put the transmission in neutral. Do not apply the parking. Check the distance between the bottom of the left axle stop and the top of the axle U-bolt or U-bolt pad. IMPORTNT: Suspensions with Dual-Leaf Springs, and all Vehicles built before ugust 4, 00: Measure between the top of the U-bolt and the bottom of the axle stop (distance ). Suspensions with Single-Leaf Springs, built after ugust 4, 00: Measure between the top of the U-bolt pad and the bottom of the axle stop (distance ).. If the distance is within the acceptable range, ride height is adjusted correctly. pply the parking If the distance is not within the acceptable range, repeat the adjustment procedure. Heavy-Duty Trucks Service Manual, Supplement 38, July 009 0/3
3.05 Freightliner irliner Suspension 09/7/005 f30934a Measure Point Suspension Height Measurement ( or ) Min Target Max = Measure Here if uilt efore ugust 4, 00 = Measure Here if uilt fter ugust 4, 00-3/8 inch (60 mm) -/ inch (64 mm) -7/8 inch (73 mm) Table 4, Suspension Ride Height Measurement, Single-Leaf Spring, 0k/k/5k/8k Mid Ride Height and 40k Low and Mid Ride Height Vehicle with a Meritor WCO Valve djustable Installation IMPORTNT: efore checking the irliner suspension height, make sure there is no load on the chassis. For tractors, unhitch the trailer. Trucks must be empty.. Park the vehicle on a level surface, using a light application of the Do not apply the parking Put the transmission in neutral. uild the secondary air pressure to at least 00 psi (690 kpa). Shut down the engine.. Mark the location of the front and rear tires on the floor, then chock the tires on one axle only. 3. Check the length of the horizontal control lever between its pivot points. See Fig. 4. The length should be 8 inches (03 mm). If needed, adjust the length of the horizontal control lever. 3. Loosen the adjustment locknut on the control shaft. 3. Move the horizontal control lever fore or aft until the length between the pivot points is 8 inches (03 mm). 3.3 Tighten the adjustment locknut 6 lbf in (700 N cm). 4. irliner suspensions may have one of three types of axle seats; see Fig. 5. The three styles are: a one-piece, cast axle seat, that is not welded to the axle housing; a one-piece, cast axle seat, that is welded to the axle housing; a two-piece, fabricated axle seat that is welded to the axle housing. 0/4 Heavy-Duty Trucks Service Manual, Supplement 38, July 009
Freightliner irliner Suspension 3.05 //005 f3093a Measure Point Suspension Height Measurement ( or ) Min Target Max = Measure Here if uilt efore ugust 4, 00 = Measure Here if uilt fter ugust 4, 00 -/8 inch (54 mm) -9/3 inch (58 mm) -5/8 inch (67 mm) Table 5, Suspension Ride Height Measurement, Single-Leaf Spring, 0k/k/5k Low or Extra Low Ride Height IMPORTNT If the axle seat is a two-piece welded type, subtract /4 inch (6 mm) from the minimum, target, and maximum heights when adjusting the suspension height. 5. Measure the distance from the bottom of the left forwardmost axle stop to the top of the axle U-bolt; see Table, Table, Table 3, Table 4, and Table 5 for an acceptable range of heights for each suspension. 6. If the distance is within the acceptable range, ride height is adjusted correctly. pply the parking If the distance is not within the acceptable range, go to the next step. 7. Loosen the two fasteners that attach the heightcontrol valve to the mounting bracket. 8. Rotate the height-control valve clockwise (as you are facing it from the driver s side of the vehicle). Let the air exhaust from the valve until the distance from the bottom of the left forwardmost axle stop to the top of the axle U-bolt is inches (5 mm) or less. 9. Rotate the height-control valve counterclockwise, and raise the suspension height to the target height (previously noted from the appropriate table). Stop the air flow to the air bag by rotating the height-control valve clockwise. 0. Center the height-control valve. 0. Rotate the valve very slightly clockwise and counterclockwise until you can insert a 5/3-inch (4-mm) pin or drill bit into the valve centering hole. Don t rotate the valve too much, or you will change the suspension height. 0. Tighten the height-control valve mounting fasteners firmly.. Drive the vehicle unloaded for about /4 mile (/ km), then stop the vehicle in the exact loca- Heavy-Duty Trucks Service Manual, Supplement 38, July 009 0/5
3.05 Freightliner irliner Suspension 4 5 3 3 05/05/94 f30385. djustable Installation. Fixed Installation. Height-Control Valve. Mounting racket 3. Height-Control Valve Mounting Fasteners 4. Slotted Hole 5. Round Hole Fig., Meritor WCO Height-Control Valve Installation tion (as previously marked) of the original measurement. Park the vehicle using a light brake application. Chock the tires on one axle only, and put the transmission in neutral. Do not apply the parking. Check the adjusted distance between the bottom of the left forwardmost axle stop and the top of the axle U-bolt. It should be within the acceptable range for the applicable suspension previously noted. 3. If the distance is not within the acceptable range, repeat the adjustment procedure. If the distance is within the acceptable range, ride height is adjusted correctly. pply the parking Vehicle With a Meritor WCO Valve Fixed Installation IMPORTNT: efore checking the irliner suspension height, make sure there is no load on the chassis. For tractors, unhitch the trailer. 0/6 Heavy-Duty Trucks Service Manual, Supplement 38, July 009
Freightliner irliner Suspension 3.05 3 4 5 3 4 6 7 5 5 0//000 f3056a. Valve Mounting racket. Height-Control Valve 3. Stud olt 4. Linkage Rod 5. xle Fig. 3, arksdale Height-Control Valve Installation (side view) Trucks must be empty. In order to adjust the suspension height, you must change the length of the vertical linkage rod using the following procedure.. Park the vehicle on a level surface, using a light application of the Do not apply the parking Put the transmission in neutral. uild the secondary air pressure to at least 00 psi (690 kpa). Shut down the engine.. Mark the location of the front and rear tires on the floor, then chock the tires on one axle only. 3. Check the length of the height-control valve horizontal control lever; see Fig. 4. See Table 6 for the correct length. If the length is acceptable, go to the next step. If the length is not acceptable, adjust the length of the horizontal control lever as follows. /04/95. Measure the length of the horizontal control lever between these two points.. Measure the length of the vertical linkage rod between these two points.. Height-Control Valve. djustment Locknut 3. Horizontal Control Lever f3036 4. Cotter Pin 5. djustment Clamp 6. Vertical Linkage 7. Valve Centering Hole Fig. 4, Meritor WCO Height-Control Valve Horizontal Control Lever and Vertical Linkage Rod Measurement 3. Loosen the adjustment locknut on the control shaft. 3. Move the horizontal control lever fore or aft until it is the correct length. 3.3 Tighten the adjustment locknut 6 lbf in (700 N cm). 4. Measure the distance from the bottom of the left forwardmost axle stop to the top of the axle U-bolt. See Suspension Ride Height Measurement, Table, Table, Table 3, Table 4, and Table 5 for an acceptable range of heights for each suspension. Heavy-Duty Trucks Service Manual, Supplement 38, July 009 0/7
3.05 Freightliner irliner Suspension If the distance is within the acceptable range, ride height is adjusted corrcetly. pply the parking If the distance is not within the acceptable range, go to the next step. 5. Determine how much the suspension height needs to be adjusted so the distance matches the target height in the applicable table. Then, using Table 7, find the amount that the length of the vertical linkage rod needs to be changed; see Fig. 4. 6. djust the length of the vertical linkage rod as needed, adding or subtracting the amount shown in Table 7. NOTE: If the vertical linkage rod is too short, replace it with a new rod, part number 6 3485 000. The vertical linkage rod should be long enough so that at least / inch (3 mm) of it fits into both flexible end-sections of the linkage. 6. Mark the existing length of the vertical linkage rod between the upper and lower flexible end-sections of the linkage; see Fig. 4. 6. Loosen both linkage adjustment clamps. 6.3 Slide the flexible end-sections of the linkage over the linkage rod until the rod is the correct length. To increase the suspension height, lengthen the vertical linkage rod; to decrease the suspension height, shorten the rod. 6.4 Tighten the adjustment clamps. 7. Drive the vehicle unloaded for about /4 mile (/ km), then stop the vehicle in the exact location (as previously marked) of the original measurement. Park the vehicle using a light brake application. Chock the tires on one axle only, and put the transmission in neutral. Don t apply the parking 8. Check the distance between the bottom of the left forwardmost axle stop and the top of the axle U-bolt. C /09/95 f3503a. One-Piece Cast xle Seat, Not Welded. One-Piece Cast xle Seat, Welded C. Two-Piece Fabricated xle Seat, Welded. xle Housing. Welds Fig. 5, xle Seats 0/8 Heavy-Duty Trucks Service Manual, Supplement 38, July 009
Freightliner irliner Suspension 3.05 9. If the distance is within the acceptable range, ride height is adjusted correctly. pply the parking If the distance is not within the acceptable range, repeat the adjustment procedure. Horizontal Lever Length xle Designation Horizontal Control Lever Length: inches (mm) Meritor RS3 6 8 (03) Meritor 3 80 7-3/8 (87) Meritor SQ00 9-/4 (35) Meritor SSHD 9 (9) Meritor RT40 45 9-3/4 (48) Meritor RT44 45 9-3/4 (48) Meritor RT46 60 8-/8 (06) Eaton 305 SC 7-/4 (84) Eaton 40 8-3/8 (3) Eaton 404 8-3/8 (3) Eaton 46 8-3/8 (3) Table 6, Horizontal Control Lever Length Vertical Linkage Length Changes Suspension Height Correction: inches (mm) Vertical Linkage Length Correction: inches (mm) (5) -5/6 (33) Table 7, Vertical Linkage Lengths Vertical Linkage Length Changes Suspension Height Correction: inches (mm) Vertical Linkage Length Correction: inches (mm) /6 () /6 () /8 (3) 3/6 (5) 3/6 (5) /4 (6) /4 (6) 5/6 (8) 5/6 (8) 3/8 (0) 3/8 (0) / (3) 7/6 () 9/6 (4) / (3) 5/8 (6) 9/6 (4) 3/4 (9) 5/8 (6) 3/6 () /6 (7) 7/8 () 3/4 (9) (5) 3/6 () -/6 (7) 7/8 () -3/6 (30) 5/6 (4) -/4 (3) Heavy-Duty Trucks Service Manual, Supplement 38, July 009 0/9