HlTECHNICAL
®PROCEDURE
HTB® l 75M Mechanical Rear
Suspension for Workhorse UFO
Motorhome Chassis
SUBJECT: Service Instructions
LIT NO: 17730-256
DATE: September 2014
REVISION: B

MtM!i.!i9•!iiMIF4
Section 8

Component Replacement .......... 24

Section l

Introduction ....................... 2

Section 2

Product Description ................ 2

Suspension Overview ................ 24

Section 3

Important Safety Notice ............. 4

Fasteners ......................... 24

Section 4

Parts List .......................... 8

Section 5

Special Tools ..................... 10

Section 6

Preventive Maintenance ........... 11

Shock Absorber ..................... 24
Coil Spring ............ .

Component Inspection ............... 11
Li-bolts ................ .

" 12

Axle Brackets ............. .

" 12

Coil Spring Hanger ......... .

'''' 28

Frame Hanger ........... .

'''' 28

Longitudinal Torque Rod .............. 29

Longitudinal Torque Rods ............. 13

Torque Rod Bushing ...... .

''' 31

Torque Box .............. .

"' 33

. ... 14

Clamp Group (Top Pad, Lower Coil Spring
Bracket, Li-bolts) .................. 36

Alignment & Adjustments .......... 16

Auxiliary Bumper .................... 39

Checking and Correcting Axle Alignment .. 16

Cross Member................ .

Shock Absorber Inspection . . . . . .

Section 7

'26

Pinion Angle ....................... 22

Section 9

'39

Troubleshooting Guide ............. 41

Section 10 Torque Specifications...

. . 42

[ffiHENDRICKSON
7Qe #"O?.H .IP.-«'~ Oh Us®

'H
l!:!.I

HTB® l 75M for Workhorse UFO Motorhome Chassis
FIGURE 2-1
LIGHlWEIGHT, NON-TORQUE REACTIVE MECHANICAL REAR SUSPENSION

HTB® l 75M SPECIFICATIONS'
HTB l75M
17,500 pounds
530 pounds
100%
Single
26,000 pounds
30,000 pounds
8.625" ± 0. 139"
None

Capacity
Installed Weight
On-highway Rating
Axle Configuration
GVW Approval
GCW Approval
Ride Heights
Engine Torque Restrictions
Applications'

RV

Yes
Yes

Motorhome

17730-256

l.

Actual product pertormonce may vary depending upon vehicle configuration, operation, service and
other factors.All applications must comply with applicable Hendrickson specifications and must also be
approved by the respective vehicle manufacturer with the vehicle in its original. as-built configuration.
Contact Hendrickson and the respective vehicle manufacturer for approval of additional applications.

2.

These ore indicative of typical applications. Please contact your dealer or o Hendrickson service representative before using suspension on other applications.

3

Product Description

'H

HTB® l 75M for Workhorse UFO Motorhome Chassis

l!!I

• SAFETY PRECAUTIONS

A

WARNING

FASTENERS
DISCARD USED FASTENERS. ALWAYS USE NEW FASTENERS TO COMPLETE A REPAIR. FAILURE TO
DO SO COULD RESULT IN FAILURE OF THE PART, OR MATING COMPONENTS, LOSS OF VEHICLE
CONTROL, PERSONAL INJURY, OR PROPERTY DAMAGE.
LOOSE OR OVER TORQUED FASTENERS CAN CAUSE COMPONENT DAMAGE, LOSS OF VEHICLE
CONTROL, PROPERTY DAMAGE, OR SEVERE PERSONAL INJURY. MAINTAIN CORRECTTORQUE VALUE
AT ALL TIMES. CHECK TORQUE VALUES ON A REGULAR BASIS AS SPECIFIED, USING A REGULARLY
CALIBRATED TORQUE WRENCH. TORQUE VALUES SPECIFIED IN THIS TECHNICAL PUBLICATION ARE
FOR HENDRICKSON SUPPLIED FASTENERS ONLY. IF NON HENDRICKSON FASTENERS ARE USED,
FOLLOW TORQUE SPECIFICATION LISTED IN THE VEHICLE MANUFACTURER'S SERVICE MANUAL.

A

WARNING

LOAD CAPACITY
ADHERE TO THE PUBLISHED CAPACITY RATINGS FOR THE SUSPENSION. ADD-ON AXLE
ATTACHMENTS AND OTHER LOAD TRANSFERRING DEVICES CAN INCREASE THE SUSPENSION LOAD
ABOVE ITS RATED AND APPROVED CAPACITIES, WHICH CAN RESULT IN COMPONENT DAMAGE AND
LOSS OF VEHICLE CONTROL, POSSIBLY CAUSING PERSONAL INJURY OR PROPERTY DAMAGE.

A

WARNING

TORCH/WELDING
DO NOT USE A CUTTING TORCH TO REMOVE ANY FASTENERS. THE USE OF HEAT ON SUSPENSION
COMPONENTS WILL ADVERSELY AFFECT THE STRENGTH OF THESE PARTS. A COMPONENT
DAMAGED IN THIS MANNER CAN RESULT IN THE LOSS OF VEHICLE CONTROL AND POSSIBLE
PERSONAL INJURY OR PROPERTY DAMAGE.
EXERCISE EXTREME CARE WHEN HANDLING OR PERFORMING MAINTENANCE IN THE AREA OF THE
EQUALIZING BEAM. DO NOT CONNECT ARC WELDING GROUND LINE TO THE EQUALIZING BEAM.
DO NOT STRIKE AN ARC WITH THE ELECTRODE ON THE EQUALIZING BEAM AND AXLE. DO NOT USE
HEAT NEAR THE EQUALIZING BEAM ASSEMBLY. DO NOT NICK OR GOUGE THE EQUALIZING BEAM.
SUCH IMPROPER ACTIONS CAN DAMAGE THE EQUALIZING BEAM ASSEMBLY, AND CAN CAUSE
LOSS OF VEHICLE CONTROL AND POSSIBLE PERSONAL INJURY OR PROPERTY DAMAGE.

A

WARNING

MODIFYING COMPONENTS
DO NOT MODIFY OR REWORK PARTS WITHOUT AUTHORIZATION FROM HENDRICKSON. DO NOT
SUBSTITUTE REPLACEMENT COMPONENTS NOT AUTHORIZED BY HENDRICKSON. USE OF MODIFIED,
REWORKED, SUBSTITUTE OR REPLACEMENT PARTS NOT AUTHORIZED BY HENDRICKSON MAY NOT
MEET HENDRICKSON'S SPECIFICATIONS, AND CAN RESULT IN FAILURE OF THE PART, LOSS OF
VEHICLE CONTROL, POSSIBLE PERSONAL INJURY OR PROPERTY DAMAGE, AND WILL VOID ANY
APPLICABLE WARRANTIES. USE ONLY HENDRICKSON AUTHORIZED REPLACEMENT PARTS.

A

CAUTION

PROCEDURES AND TOOLS
ATECHNICIAN USING A SERVICE PROCEDURE OR TOOL WHICH HAS NOT BEEN RECOMMENDED BY
HENDRICKSON MUST FIRST SATISFY HIMSELF THAT NEITHER HIS/HER SAFETY NOR THE VEHICLE'S
SAFETY WILL BE JEOPARDIZED BY THE METHOD OR TOOL SELECTED. INDIVIDUALS DEVIATING IN
ANY MANNER FROM THE INSTRUCTIONS PROVIDED WILL ASSUME ALL RISKS OF CONSEQUENTIAL
PERSONAL INJURY OR DAMAGE TO EQUIPMENT INVOLVED.

A

WARNING

JACKING METHODS
IMPROPER JACKING METHODS CAN RESULT IN LOSS OF WARRANTY, COMPONENT DAMAGE,
VEHICLE DAMAGE, SEVERE PERSONAL INJURY, OR DEATH. ALWAYS CHOCK THE WHEELS OF
THE VEHICLE TO PREVENT VEHICLE MOVEMENT. SUPPORT THE VEHICLE WITH SAFETY STANDS.
NEVER WORK ON A VEHICLE SUPPORTED ONLY WITH A FLOOR JACK. REFER TO THE VEHICLE
MANUFACTURER FOR PROPER JACKING INSTRUCTIONS.

17730-256

5

Important Safety Notice

'H
l!!J

HTB® l 75M for Workhorse UFO Motorhome Chassis

A

WARNING

A

WARNING

SHOCK ABSORBERS

THE SHOCK ABSORBERS ARE THE REBOUND TRAVEL STOPS FOR THE SUSPENSION. ANYTIME THE
AXLE ON A HTB MECHANICAL SUSPENSION IS SUSPENDED IT IS MANDATORY THAT THE SHOCK
ABSORBERS REMAIN CONNECTED. FAILURE TO DO SO WILL RESULT IN OVER-EXTENSION OF THE
SUSPENSION, CAUSING DAMAGE TO COMPONENTS. REPLACEMENT OF SHOCK ABSORBERS WITH
NON-HENDRICKSON PARTS CAN ALTER THE REBOUND TRAVEL OF THE SUSPENSION.
COIL SPRING STORED ENERGY

IMPROPER RESTRAINT OF COMPRESSED COIL SPRINGS CAN RESULT IN A VIOLENT SHIFT OF
COMPONENTS, AND CAUSE SEVERE PERSONAL INJURY, DEATH AND/OR PROPERTY DAMAGE. FULLY
DECOMPRESS OR SECURELY RESTRAIN COMPRESSED COIL SPRINGS BEFORE LOOSENING ANY
CLAMP GROUP HARDWARE OR DISASSEMBLING ANY PART OF THE SUSPENSION SYSTEM. DO NOT
OPERATE THE VEHICLE WITHOUT COIL SPRINGS PROPERLY INSTALLED AND RESTRICTED BY OTHER
SUSPENSION COMPONENTS. SEE FURTHER INSTRUCTIONS AND DETAILS IN THIS PUBLICATION.

A

WARNING

PARTS CLEANING

SOLVENT CLEANERS CAN BE FLAMMABLE, POISONOUS, AND CAUSE BURNS. TO HELP AVOID
SERIOUS PERSONAL INJURY, CAREFULLY FOLLOW THE MANUFACTURER'S PRODUCT INSTRUCTIONS
AND GUIDELINES AND THE FOLLOWING PROCEDURES:
1.
2.
3.
4.
5.
6.

WEAR PROPER EYE PROTECTION.
WEAR CLOTHING THAT PROTECTS YOUR SKIN.
WORK IN AWELL-VENTILATED AREA.
DO NOT USE GASOLINE OR SOLVENTS THAT CONTAIN GASOLINE. GASOLINE CAN EXPLODE.
ACIDIC SOLUTIONS CANNOT BE USED ON ALUMINUM COMPONENTS.
HOT SOLUTION TANKS OR ALKALINE SOLUTIONS MUST BE USED CORRECTLY. FOLLOW The
MANUFACTURER'S RECOMMENDED INSTRUCTIONS AND GUIDELINES CAREFULLY TO HELP
PREVENT PERSONAL ACCIDENT OR INJURY.

DO NOT USE HOT SOLUTION TANKS OR WATER AND ALKALINE SOLUTIONS TO CLEAN GROUND OR
POLISHED PARTS. DOING SO WILL CAUSE DAMAGE TO THE PARTS AND VOID WARRANTY.

17730-256

7

Important Safely Notice

'l!!J
H1

HTB® l 75M for Workhorse UFO Motorhome Chassis

KEY NO. PART NO.
66512·000
66319·000
66315·000
66317·000

1
2
3
4
5

66316·001
66316·002
58821·022
6
7
8
9
10
11

66323-000

12
13
14
15
16
17

32043-002
32043·019
47764-000
22962·004
66308-001

22962-004
48411-015
47691-000
57856-000
49176-027

60961-149
18
19

DESCRIPTION

NO.REQ.

Frame Hanger
Coil S12ring - 17.SK Pounds
Coil Sg;ring Hanger
Lower Coil SQring Bracket
Axle Top Pod
left Hand
Right Hand
Axle Clamp Fastener Kil, Axle Set,
Includes Key Nos. 6-8
5/s"-18 UNF U-bolt- 9.45"
'5/s"· 18 UNF U-boltTall Nut
S/s" Hardened Flot Washer
Torgue Rod Assembly Includes Key No. l 0
Torgue Rod Bushing
lf32"Torgue Rod Shim (as reguired}
Torque Rod Fastener Kit, Axle Set,
Includes Key: Nos. 12-15
5/s"-11 UNC Hex Bolt· 2.75"
5/a"-11 UNC Hex Bolt - 5.5"
5/a"-11 LINC Locknut
5/a" Hardened Flot Washer
Auxiliaty Bum1:1er
*Ml 0 Flanged Locknut
Shock Absorber Service Kit, One Side,
Includes Ke~ Nos. 18·23
**Shock Absorber Assembly
Ml 2 Stud Mount. Includes Key: Nos.19-20
*'"Upper Shock Spacer Length 115/16"

2
2
2
2

DESCRIPTION

2
**Lower Shock S12acer Length 23/16
4
**Rubber Isolator
4
**Retaining Washer
4
**M 12 Flange locknut
Torque Box Cross Member Assembly,
1
Includes Key Nos. 24-31
Torgue Bo~ Re~laces 647B5-004
1
Cross Member C-Channel
1
Cross Member Bar Pin Clami;i (Aluminum}
4
Cross Member Gusset
2
RH Top. lH Bottom
2
LH ToQ, RH Bottom
'is"-11 UNC Hex Bolt - 8.0"
8
S/a"-11 LINC Locknut
8
S/s" Hardened Flat Washer
16
*Torgue Box Axle Bracket-Dana (Short)
1
*Torgue Box Axle Brocket- Dana (Long)
1
5/s" Hardened Flat Washer
16
Non-Adjustable Axle Brocket Bar Pin Clam1:1
2
•**Adjustable Axle Brocket Bar Pin Clamg
2
...Axle Brocket Shims
4
Torque Box Axle Fastener Kit, Axle Set,
Includes Ke~ Nos. 38-40
%"-10 LINC Hex Bolt-5.5"
4
%"-10 UNC locknut
4
8
%" Hardened Flat Wosher
P-80 Lubricant - l 0 ml.
per Bushing l
11

66513·002

4
8
8
2
4
4
4
4
8
16
2
2
2

NO.REQ.

KEY NO. PART NO.
20
21
22
23
24
25
26

64785·005
64970·000
65144·000

27
28
29
30
31
32
33
34
35
36
37

66503-001
66503-002
32043·016
47764-000
22962-004

38
39
40

58917-003
49842·000
22962-001
70867-001

No!Shown

22962·004
66174-000
66274-000
65737-001
66027-002

2

NOTE:
• Not supplied by Hendrickson, used for reference only. Refer to vehicle manufacturer for more information. Hendrickson is not responsible for
components supplied by vehicle manufacturer.
For assistance with maintenance and rebuild instructions on these components see vehicle manufacturer.
** Item included in assembly or service kit only, port not sold separately.
•** In the oftermarket, it is acceptable to replace the non-adjustable axle bracket bar pin clomp (Key No. 35) with the adjustable bar pin clomp plus and
axle bracket shims (Key No. 36 and 37).

17730-256

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