PDF Documents Quick Reference
Taper Pin Bushing Identification
TB002-101521
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Technical Bulletin
HN Suspensions Evaluation / Replacement of Auxillary Spring and Shims
TB001-012418
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Technical Bulletin
Once bolster springs are installed, the
following evaluation should be performed.
All measurements should be made on an
unloaded truck.
-
Measure height of auxiliary spring.
Normal height of unloaded auxiliary spring
is 3 3/8”. If the height of the unloaded
auxiliary spring is 3” or less, the auxiliary
spring should be replaced.
-
Measure distance between saddle V
bracket and bottom of auxiliary spring.
Gap should not be larger than 3/8”.
-
Add or remove shims above the auxiliary
spring to achieve proper clearance.
Note: Failure to properly shim will force the load springs LP50-24000 to accept the full load and
prevent the auxiliary spring LP50-24974 from engaging and carrying the significant
portion of the load it is designed and required to carry. This produces additional stress on
the load pads LP50-24000 and may cause premature failure and could void warranty.
BOLSTER SPRING KIT
AUXILIARY LOAD SPRING KIT
Engineering Change: EM75-61001, EM75-61001-HT Air Cooler Mount Kit
EC001-040117
Technical Bulletin
EM75-61001 Air Cooler Mount Kit
To match the OE's kit, ATRO has added the following components to their original kit:
(2) Polyurethane Mount Bushings and
(2) Flat Washers
Now Contains:
- (4) Polyurethane Mount Bushings
- (4) Polyurethane Washers
- (4) Bolts
- (4) Flat Washers
- (4) Locknuts
EM75-61001-HT Air Cooler Mount Kit (High Temperature)
To match the OE's kit, ATRO has added the following components to their original kit:
(2) Polyurethane Mount Bushings and
(2) Flat Washers
Now Contains:
- (4) Polyurethane Mount Bushings (Hi Temp
- (4) Polyurethane Washers (Hi Temp)
- (4) Bolts
- (4) Flat Washers
- (4) Locknuts
Engineering Change TS34000 Crimped Design
EC002-040117
View as PDF
Technical Bulletin
TS34000 Crimped Design Torque Rod Busing
Crimped outer sleeve provides:
- Increased support for polyurethane
- Increased support and strength for urethane to metal bond
- Easy installation due to radius on leading edge of bushing
New crimped design uses PT00-52600 installation & removal tool
PT00-52600 Installation & Removal Tool
The redesigned, crimped TS38000 Torque Rod Bushing, now uses this installation tool
Torque Rods Critical for Concrete Mixers
TB001-021715
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Technical Bulletin
Torque rods have multiple purposes in truck and trailer suspensions:
- Restrain rotation of the axle housing during acceleration and braking
- Locate the axle and maintain alignment
- Control driveline angle
- Absorb leaning and cornering forces
Concrete Mixer Impact:
In a concrete mixer application the drum rotates clockwise (as viewed from the rear) and this rotation shifts the load
upwards and to the left side of the drum. This shift of load along with the high center of gravity built into the mixer design
can contribute to rollovers when the truck is making right turns. Loose or worn torque rod bushings will reduce the torque
rod’s ability to absorb the cornering forces and can contribute to the rollover possibility. For this reason it is very important
to routinely check the torque rod bushings for movement. This can be done by prying against the bushing or simply rocking
the truck forward and backward while observing the bushings. Any movement greater than 1/8” should be addressed by
replacing or re-bushing the torque rod.
Worn Torque Rods:
- Contribute to mixer roll-over
- Affect driveline angles & U-Joint wear
- Contribute to misalignment & tire wear
- Contribute to ring & pinion failure
- Can cause leaking transmission & differential seals
- Replacement Bushings
- Two-piece weldable torque rods
-
Complete OEM replacement torque rods including Terex Advance Mixer Rods
Torque Rod Finder
ATRO Torque Rod Bushings:
- Polyurethane material is more durable than rubber
- Polyurethane material is impervious to chemical attack (includes acidic cleaning solvents)
- Feature rotating pins that automatically “zero out” to ride height and allow easier installation
- Rotating pins allow for multiple OEM rod replacements with one rod
Determining Correct Replacement Torque Rods
TB001-070714
View as PDF
Technical Bulletin
Primary Torque Rod Designs (ranked by popularity):
- Straddle/Straddle: mounting bolt type on both ends
- Straddle/Taper: one end mounting bolt type, one end tapered pin end
- Taper/Taper: tapered pin on both ends
Torque Rod Finder
ATRO Torque Rod Solutions:
- Two-Piece Weldable Torque Rods: two ends welded to length
- Direct Replacement Torque Rods: complete rod
If a customer prefers a direct replacement torque rod, the only tool needed to identify the correct replacement rod is a tape measure.
Information to get from customer:
- Torque Rod Design (i.e., taper/taper)
- Center to Center Length
You can verify the accuracy of the chart by checking against the listed OEM cross reference number.
ATRO torque rod ends feature a polyurethane material
with free rotating pins.
For the next repair cycle, ATRO offers bushings for these replacement rods.
In many cases, the OEM bushings can be replaced with an ATRO bushing with its unique features.
Spring Eye Bushings
TB001-072017
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Technical Bulletin
Relative to the following ATRO Parts:
When switching from threaded, metal style pin and bushing to ATRO’s Polyurethane Spring Eye Bushing, use the conversion chart below, find your corresponding bushing and pin number and pick the ATRO part number in the box where they intersect. This is a total replacement for both the pin and bushing.
The ATRO parts listed in the conversion chart below are designed as a replacement for the threaded bushing style spring pins. The ATRO parts are a one piece design.
ATRO Features and Benefits:
- Simplify by replacing both the pin and bushing
- Self lubricating quality, meaning no more grease
- ATRO’s polyurethane material is impervious to oil, grease, brine, cleaning solvents, hydraulic fluids and diesel fuel
- Premium polyurethane is formulated for superior performance
Conversion Chart: Threaded Spring Pin Bushing to Polyurethane
Bushing Part Number Conventional & Cab Over Trucks 4" Springs |
| Paccar B13-1000 Dayton Parts TB77 Automann MTB178 | Paccar B13-1002 Dayton Parts TB81 Automann MTB186 |
Pin Part Number | | |
Paccar B65-1002 Dayton Parts 327-537 Automann M5448 | SP59-11010 | NOT AVAILABLE |
Paccar B65-1008 Dayton Parts 327-540 Automann M5449 | SP59-11006 | SP59-11007 |
Paccar B65-6008 Dayton Parts 327-544 Automann M5447 | SP00-11005 | SP00-11013 |
ATRO Installation Tools:
KT50-2500 Haulmaax Suspension Kit
TB002-032416
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Discontinued Part Number
Technical Bulletin
ATRO has discontinued the KT50-25000 Haulmaax® Suspension Kit. In its place you should order the KT50-25002 or the KT50-25003. (The KT50-25003 kit includes a set of 4 wear plates.)
The difference between the KT50-25000 and the KT50-25002 is the Auxiliary Load Spring has been replaced with the NEW Progressive Load Spring.
In 2014, Hendrickson Truck Commercial Vehicle Systems
introduced the Progressive Load Spring for Haulmaax®
vocational rear suspension system. The NEW Progressive
Load Spring works together with the bolster springs.
The PLS replaces the auxiliary load spring. It provides
improved ride quality and stability.
As payload increases, the PLS further engages and functions
together with the rubber bolster springs to provide additional
stability. The PLS’s constant engagement also eliminates the
need for shim adjustments, resulting in reduced maintenance
and lower cost.
NOTE:
- The LP50-24974 Auxiliary Load Spring with Hardware is still available for purchase.
- It is also available in the LP50-24746 Kit for Weight Bias Vehicles.
Intraax/Vantraax Tri-Functional Bushing
TB002-071018
View as PDF
Why Choose Premium ATRO Products
Technical Bulletin
ATRO has two bushing choices to replace the OEM #S-24691 Intraax/Vantraax trailer suspension bushing
Both ATRO products offerthese benefits:
- ATRO's polyurethane is impervious to chemical attack unlike rubber bushings
- Oil & Greese
- Calcium Chlordie (Winter Salt Melt)
- Citric Acid & Acid Based Cleaners
- Ethylene Glycol
- Gas, Kerosene & Diesel Oil
- Many additional contaminants
- ATRO's polythurethane is 2-5 times stronger than rubber!
Results: ATRO Intraax Bushings last longer and are backed by the industry's best warranty.
- The bushing has voids, similar to the OEM bushing.
- It's outside diameter (OD 5 7/8" is similar to the rubber bushing's 6" OD.
- ATRO's bushing and the rubber bushing are compressed into the 5 1/2" ID beam hole.
- The ATRO offers the PT50-59307 installation tool, which can be used to install both ATRO's bushing and the rubber OEM bushing.
ATRO Part Number | Easy Install | Voids | Inner Pin Rotation | Bolt type | Torque |
PB50-36000 | No | Yes | No | Hex Head | 500-550 ft. lb. |
PB50-36001 | No | Yes | No | Shear Bolt | Head snaps off at proper torque |
TR59-41474 Steel Torque Rod
TB002-092017
View as PDF
Technical Bulletin
Replaces:
- Kenworth K195-474
- Kenworth K195-472 (no bushings)
Application:
With High Articulating Straddle Pin Bushing TS59-22400
The Kenworth aluminum OEM rods are mounted in a V
formation with the torque rod straddle bushing mounting
pins facing up and down. When the axles articulate the pin
is forced to move sideways (conical movement) in the
bushing. This movement is not designed into the OEM rubber
bushing or the ATRO TS38000. This forced movement will
rapidly wear the torque rod bushing. In severe cases, it can contribute to breaking the aluminum torque rod. ATRO
designed a torque rod bushing with a higher allowable side to side, conical movement in the bushing. This bushing
uses an oval pin configuration and articulation voids designed into the polyurethane. This design allows the
bushing to move 12° in both directions, 24° total movement. This greatly extends the bushing life and relieves the
stress on the torque rod.
The ATRO TS59-22400 high articulating bushing is a direct replacement for the OEM rubber bushing and can be
pressed into the aluminum OEM torque rod.
The ATRO TR59-41474 replacement torque rod is a steel replacement rod with the two high articulating bushings
included and directly replaces the OEM aluminum torque rod.
Torque Rod Bushing, High Articulation
Replaces:
- Kenworth 227720, 836940, 839310
NOTE:
For additional information in regards to the TR59-41474 and TS59-22400, please see ATRO’s
Product Spotlight PS005-022217
Mack Pads Indentification
TB003-072314
View as PDF
Technical Bulletin
LP50-24179 Haulmaax® Bolster Spring Kit
TCB001-022312
View as PDF
Technical Bulletin
ATRO bolster springs are designed to meet the OE Load Curve. ATRO’s Polyurethane is stronger not harder than the OE rubber and is designed to improve suspension performance.
NEW BOLSTER SPRING FEATURES & BENEFITS:
- Improved durability, enhanced load handling capabilities and increased stability by removing grooves to provide more load bearing area
- Reduced ride height by 3/8” to ensure overload spring can engage
Notes:
- Do not use both old and new bolster springs on the same truck
- Do not mix rubber bolster springs with any ATRO bolster springs on the same truck
- Adjust Auxiliary Springs to within ¼”- ½” of shim plates when truck is unloaded. Auxiliary Springs should be contacting the shim plates when truck is fully loaded.
- Any excessively worn Auxiliary Springs must be replaced. ATRO’s new progressive load spring LP50-24778 is recommended. The original auxiliary spring LP50-24947 is also available.
SW59-29000 & SW59-29001 Redesigned Kenworth Sway Bar Kits
TG031309
View as PDF
Technical Bulletin
The listed guidelines must be followed concerning the ATRO Kenworth Sway Bar
SW59-29000 and SW59-29001 Sway Bar Kits:
-
Kits are only intended for retrofitting the Kenworth Airglide 200 suspension to the
Kenworth Airglide 380/400 suspension and/or for rebuilding the Kenworth Airglide
400/460/690 suspension for all applications
-
Use only ATRO polyurethane bushings in conjunction with ATRO sway bars (bushings are
supplied with each sway bar kit)
-
Shaft collar (SW59-29599 optional) & thrush bushing (SW59-29454 optional) not required
on this design.
- Ensure all torque rods and torque rod bushings are in good working condition
- Maintain proper ride height, as specified by the OEM application
- Follow industry best practice for install, repair and safety
- Do not re-use old bushings or hardware
-
Do not mix ATRO sway bars with non-parabolic designed sway bars or other
manufacturer’s sway bars
-
It is recommended that procedures from a factory service manual be followed for removal,
replacement and proper torque specifications
PB75-29101 & PB75-29674 Peterbilt Air Leaf Bushing Kits
TG103009
View as PDF
Technical Bulletin
- Insert the inner polyurethane sleeves into each end of the eye casting. Insert the steel spacer tube and seat the bushings as far into the casting as is possible before the spacer tube tightens up. Remove the spacer tube.
- NOTE: Please be aware that the inner polyurethane sleeves
in our kits are tapered and must be inserted into the eye
casting small end first. (The OE rubber parts are straight
sided and can be installed from either end.)
-
Insert the eye casting into the hanger and align
the eye casting eye with hanger’s eye. (This
may be a tight fit.)
-
Insert the spacer tube through the hanger
eye and into the inner polyurethane
bushings.
-
nstall the hard polyurethane washers
into both ends of the hanger (stepped side
inwards). You may have to tap them down to
seat them.
-
Insert a compression washer on both ends
with counter-bored side facing outwards.
-
Run bolt through entire assembly from
the outboard side. (If end of bolt does not protrude sufficiently to start nut either reseat the hard
polyurethane washers or use a longer bolt and nut to reseat the whole assembly.)
- Install nut and torque to manufacturer’s specification. (Do not reuse old bolts.)
TR59-41474 Torque Rod Kenworth AirGlide
View as PDF
Technical Bulletin
Description:
Torque Rod
Cross-references:
Kenworth#: K195-474 (Aluminum)
Application:
Kenworth Airglide 200/400/460/690
The TR59-41474 Torque Rod was designed specifically for the
Kenworth Airglide suspension and replaces the original aluminum rod with
a stronger, more durable alternative. The Kenworth Airglide suspension design
combines the transverse and tracking torque rods into a dual rod, V configuration with
the torque rods mounted vertically. This design requires an extreme amount conical motion from
the bushings due to the torque rods being mounted vertically instead of the more familiar horizontal
arrangement. This mounting configuration places much more bending stress on the rod. To handle
this additional stress the improved ATRO rod features forged steel rod eyes and a heavy-walled steel
shaft. Additional conical movement was also added by
equipping our rods for this application with the new ATRO
TS59-22400 High Articulation Bushing. While this bushing
does not have the trademark ATRO rotating feature which
has made our standard torque rod bushings so popular in
the heavy duty trucking industry, it does utilize articulation
voids and a modified pin to provide the extra vertical
motion required by this very demanding application. This
bushing is the only bushing approved by ATRO for use
in Kenworth Airglide 200/400/460/690 aluminum rods
(K195-474 and K195-472).
Suspension Inspection Maintenance
TT001-050118
View as PDF
Technical Bulletin
Today’s heavy duty suspensions are called on to carry loads for more miles and under harsher conditions than ever before.
Keeping an eye on these suspensions help keep trucks on the road and stress free. Air Spring and Leaf Spring suspensions
each have critical wear points that need to be reviewed regularly.
Common Air Suspensions: Freightliner FASII, Kenworth AirGlide 400, Peterbilt Air Leaf, Peterbilt Air Trac
KEY FAILURE POINTS: AIR SPRING
Leaking air or restricted air flow
-
If both sides are flat, there may be a leak
between the air brake system and the
suspension air system
-
If flat on one side, there may be a leak
between the height control valve and the
air spring
Automatic height control valve
-
Test it: disconnect linkage and move
actuating arm up and down to see if air
bag inflates/deflate.
Bushings
-
Place pry bar between trailing arm
and hanger and check for movement -
abnormal tire wear is a good indicator of
bushing wear
Shocks - should be warm to the touch
after vehicle operation
-
If cold, the shock is not functioning
properly and should be replaced
-
If shock can be easily compressed after
removal, shock should be replaced
- Check for shock bushing wear
Under-inflation - slight positive pressure
maintains shape of air bag and prevents
folding/pinching
Causes of Air Spring failure:
- Overextension
- Abrasion
- Contamination
- uspension Misalignment
- Road Hazards
- Fatigue/Old Age
MEASURING A TORQUE ROD