Content. KEY Benefit Tech Tip Wear Item

Transcription

1 - Page 1 -

2 Content Suspensions 2 Air Suspension Inspection/Maintenance 3 Leaf Spring Inspection 4 Most Common & Preventable Failures 5 s 6 ATRO Free Rotation Design 11 ATRO Information Charts 12 Chalmers Series 14 Freightliner - FAS II 16 Hendrickson - Haulmaax 18 Hendrickson - HN 22 Hendrickson - Intraax/Vantraax 26 Hendrickson - Primaax 30 Hendrickson - RS 34 Hendrickson - RT 36 Hutch - H/CH 7700/ International - Corp Air/IROS 40 International - Z Air Spring 42 Kenworth - AirGlide Kenworth - AirGlide 200/ Kenworth - AirGlide 380/Peterbilt - Flex Air 48 Mack - Camelback 50 Peterbilt - Air Leaf 52 Peterbilt - Air Trac 53 Peterbilt - Low Mount Air Leaf 56 Peterbilt - New Low Air Leaf 58 High Temperature Underhood Mounts 60 Suspensions At A Glance 62 KEY Benefit Tech Tip Wear Item Copyright 2014 by ATRO Engineered Systems, Inc. ALL RIGHTS RESERVED. This book contains material protected under International and Federal Copyright Laws and Treaties. Any unauthorized reprint or use of this material is prohibited. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system without express written permission from ATRO Engineered Systems, Inc. ATRO is not liable for any errors herein. All manufacturers names and part numbers used are trademarked by the respective manufacturer. These names and part numbers are being used without permission. No endorsement, affiliation or recommendation is implied. They are included for reference purposes only. Some products shown here are covered by Canadian Patent 1,327,979; Australian Patent 630, Page 2 -

3 Suspensions A suspension is a SYSTEM that relies on all the components working in harmony to perform their given function. When one part gets worn the rate of stress transfer to other parts accelerates, so early detection of any wear will save big $$ for the truck owner. Suspensions are designed to: Carry the load Provide stability against side sway Transfer driving & braking forces between frame and axles Resist drive & brake torque wind-up Produce suitable riding and cushioning properties Maintain axle alignment parallel to each other and perpendicular to the frame Provide minimum changes in drive axle pinion angles and slip joint movement Minimize load transfer between axles on tandems Provide sufficient vertical movement on tandems to maintain traction Components making up the suspension system include: Leaf springs Air Springs Torque rods Bushings Spring Pins/Shackle kits U-bolts Shocks - Page 3 -

4 Air Suspension Inspection/Maintenance 1.) Check for leaking air, or restricted air flow a.) if both sides flat, there may be a leak between the air brake system and the suspension air system. b.) if flat on one side, there may be a leak between the height control valve and the air spring. 2.) Check automatic height control valve test it: disconnect linkage and move actuating arm up and down to see if air bag inflates/deflates. 3.) Check bushings place pry bar between trailing arm and hanger and check for movement. Abnormal tire wear is a good indicator of bushing wear. 4.) Check shocks should be warm to the touch after vehicle operation. a.) if cold, the shock is not functioning properly and should be replaced. b.) If shock can be easily compressed after removal, shock should be replaced. c.) Also, check for shock bushing wear. 5.) Check for under-inflation slight positive pressure maintains shape of airbag and prevents folding/pinching. - Page 4 -

5 Air Suspension Inspection/Maintenance 6.) Causes of Air Spring Failure: a.) Overextension b.) Abrasion c.) Contamination d.) Suspension Misalignment e.) Road Hazards f.) Fatigue / Old Age Leaf Spring Inspection Check: Spring leaves Center bolt U-bolt nuts for tightness Spring clips Spring eyes (cracks, motion, lubrication) Front suspension spring shackle bolts Torque rods and all other related parts of spring suspensions: Hangers, equalizers, beam bushings Shock absorbers - Page 5 -

6 Most Common & Preventable Failures 99 U-BOLTS Never re-use U-bolts!!!! Check they are the proper grade Ensure properly aligned (check condition of top plate and saddle alignment holes) Allow suspension to settle, retorque while under load. Torque U-bolts per spec re-torque at 500 miles and check periodically 99 SPRINGS Proper U-bolt maintenance will increase spring life but springs will fatigue and wear. Check for fatigue cracks. One overlooked factor in spring longevity is brake balance. One badly adjusted brake makes the other brakes overcompensate and the spring at those axle ends will get wound up more than if all pulling equally. 99 TORQUE ROD NEGLECT This affects spring life, bushings, brackets, bolsters, shocks, air bags and other suspension hardware. Check for failure periodically especially transverse rods! 99 LUBRICATION FAILURES Wear is accelerated; wear patterns are exaggerated; inhibits normal free movement, resulting in part breakage. 99 BUSHING FAILURES Waiting to replace worn bushings until after they ve created a secondary, more expensive problem. 99 SHOCK ABSORBER NEGLECT This affects spring life, bushings and other suspension hardware not to mention additional strain and vibration on radiators, electrical systems, cabs and tires. Defective shocks can also contribute to air bag failure. - Page 6 -

7 s Purpose of a torque rod: Restrain rotation of the axle housing during acceleration and braking Locate the axle and maintain alignment Control driveline angle Absorb leaning and cornering forces Key technical point: Transverse rods must be perpendicular to the frame rail when installed. If not installed properly: The inner pin could break The torque rod could break The bushing could walk out of the rod Warranty may be void When should rods be rebushed or replaced? Bent torque rod More than 1/8 movement at the rod eye. Can check by hand or by prying against end with a bar Bushing material is torn or cracked Pin or sleeve in the rod eye is off-center (pin appears to be walking out of rod eye) Pin/sleeve is no longer located in the vertical center of the rod eye Bolt hole in straddle pins is stretched, elongated - Page 7 -

8 Restrain axle rotation Locate axle, maintain alignment Control driveline angle Absorb leaning, cornering forces Bushing material is torn or cracked Bushing walk out - Page 8 -

9 ATRO s Current Options 1.) OE direct replacement torque rods: a.) Standard Eye b.) Small Eye 2.) 2-piece torque rods 3.) Custom 1.) OE direct replacement torque rods, standard eye & small eye OE replacement rods-oe has dedicated part numbers for a specific make/model Example any KW AG400 uses a 19 ¾ straddle/straddle torque rod. ATRO offers the TR a.) ATRO 1 ½ shaft, forged eyes, holds 2 ¾ OD-sized bushings - TS38000, TT38000, TM ( standard eye ) b.) ATRO 1 ½ shaft, forged eyes, holds ATRO s 2 sleeved bushings ONLY - TS & TH ( small eye ) 2.) Weld-to-length torque rods Two-piece design, polyurethane, rebushable, available as empty male/female cores also. Welded to finished length by distributor or fleet. 3.) Custom torque rods Customer specs the center-to-center length, bushing configuration; assembled at factory and shipped finished to customer. - Page 9 -

10 - Page 10 -

11 OEM s torque rod part numbering system BUSHING BUSHING USED ANGLE INSTALLED CODE Left Right Left Right 00 Straddle Straddle Straddle Straddle Straddle Straddle Straddle Straddle Straddle Straddle Straddle Straddle Bonded bushings have multiple part numbers for the same torque rods to allow for bushing angle. ATRO s free-rotation design eliminates this excess inventory. ATRO BUSHING USED ANGLE INSTALLED PART NO. Left Right Left Right TR Straddle Straddle N/A N/A TR Straddle Straddle N/A N/A TR Straddle Straddle N/A N/A TR Straddle Straddle N/A N/A TR Straddle Straddle N/A N/A ATRO s free-rotation design allows the bushing to swivel 360 eliminating angle problems and simplifying installation. - Page 11 -

12 ATRO s Free-Rotation Design Reduces inventory levels and simplifies installation: No need to mark the old bushing position No struggle to line up the bolt holes Installs properly the first time, every time No duplicate inventory for identical rods with different bushing angles Zeroes out to ride height: ATRO s design eliminates bushing wind up and automatically zeroes out the bushing to proper ride height. This prevents unnecessary stresses from being introduced into the suspension. Please visit to see the ATRO video on ride height. - Page 12 -

13 WELD TO LENGTH COMPARISON Brand Configuration Max Length Bushings Empty Core Option ATRO 2-piece 27 Standard Yes Ultra Rod Plus 2-piece 27 or 35 Standard Yes Ultra Rod 2-piece 27 or 35 Jam (PL1146) No O&S 3-piece 27 or 35 Non-rebushable No ATRO REBUSH SELECTOR Brand Mfr s Bushings Rebush w/ ATRO ATRO std. eye TS38000, TT38000, TM38000, etc. TS38000, TT38000, TM38000 ATRO small eye TS , TH only TS , TH only UltraRod Plus Conventional, Bonded, XTRB TS38000, TT38000, TM38000 UltraRod Sleeveless rubber jam bushings PL1146, T*50-xxxxx (below*) Non-rebushable Non-replaceable Non-replaceable OE tubular, 1 7/8 eye Sleeveless rubber jam bushings PL1146, T*50-xxxxx (below*) * See ATRO Bushing Chart below - Page 13 -

14 ATRO TORQUE ROD BUSHING CHART ATRO p/n Type Rotates Replaces Notes PL1146 Straddle No OE tubular, UltraRod 5/8 bolt holes, straight body Original design, no outer sleeve TS Straddle Yes ATRO only Has outer sleeve *TS Straddle No OE tubular, UltraRod 5/8 bolt holes, wings anti-walk *TS Straddle No OE tubular, UltraRod ¾ bolt holes, *TT Taper No OE tubular, UltraRod *TT Taper No OE tubular, UltraRod 1 ¼ threads, 8 OAL 1 1/8 threads, 6 5/8 OAL *TH Hollow No OE tubular, UltraRod 7/8 bolt hole Preferred over PL1146, no outer Primaax/Firemaax, No outer sleeve No outer sleeve Primaax/Firemaax, No outer sleeve Primaax/Firemaax, no outer sleeve TH Hollow Yes ATRO only 7/8 bolt hole Has outer sleeve - Page 14 -

15 Chalmers 800 Series ATRO load spring, LP Resistant to chemicals (lime, corrosive solvents, road wash) Better load handling and ride characteristics than OE rubber and other polyurethane brands. ATRO torque rod bushing options: 2-piece design 32/suspension (PL1046, PL1047) 1-piece design 16/suspension (TH , TH ) Oversized options PL1049 (2-piece); TH (1-piece) Tech tip: Change one rod at a time! Wear items: Load spring Torque rod bushings LP Load Spring PL1026 Shock Bushing PL1046 Bushing PL1047 Bushing PL1049 Bushing (oversized) TH Bushing - Page 15 - TH Bushing TH Bushing

16 - Page 16 -

17 Freightliner FAS II The biggest concern with bonded bushings is the spring eye opens up and the bushing can walk out: With a bonded OE-style rubber bushing, the pin is not allowed to rotate, so the ENTIRE bushing can be forced to spin within the eye of the spring thus leading to the wallowed out spring eye. Bonded rubber bushings attempt to combat this with an inboard flanged end encased in a ring with detents for gripping the edge of the spring s eye. With ATRO s rotating bushing, the outer sleeve and urethane rotate around the fixed pin. ATRO design: Outer sleeved is flanged to limit lateral travel Inner pin rotates rather than entire bushing spinning ATRO torque rod: one of three torque rod length options: OE direct replacement rods TR , TR or TR The bushing in these rods is a TS it will not fit OEM or other aftermarket rods. ATRO s TS , which has no outer sleeve, can be used to rebush the OE rod or other aftermarket rods. Inner pin rotates for easy installation easy to align bolt holes (TS ). Rebushable PB Pivot Bushing (oversize version available) PL1146 Bushing - Page 17 - TS Bushing TR TR TR

18 - Page 18 -

19 Hendrickson Haulmaax Bar pin end bushings are used but there are no center bushings for the beams to pivot on. The traditional center bushing is replaced by 4 narrow bolster springs (8 per vehicle). Transverse torque rod is critical Check for wear periodically Check bolsters for cracks/debonds Replace if material cut 1 length or 3/8 in depth Replace if bond separation is > ½ deep Polyurethane material impervious to chemical attack The most common root causes of cracked or broken frame brackets: Vehicle is overloaded Worn transverse torque rods Frame bracket bolts/fasteners are loose Auxiliary spring is worn The location of the debond may be a secondary failure and the location of the debond can help locate the source of the root cause. Failure analysis: LOCATION Debond at top plate Debond at lower plate POSSIBLE PRIMARY FAILURE POINT Check torque rods for bushing failure Check bar pin end bushings for failure - Page 19 -

20 - Continued - - Page 20 -

21 Hendrickson Haulmaax Auxiliary spring is most important part!!! 3/8 or less gap for ATRO parts When measuring the gap, it is important to notice if the top shim plate is worn in the middle of at the surface where the auxiliary contacts it - the contact surface is where the measurement matters. ATRO Technical Bulletin TB Evaluation/ Replacement of Auxiliary Spring and Spring Shim on Haulmaax Suspension outlines recommended practices and required guidelines for this application and is available at under the Documents menu, Technical Bulletins section. INSTALLATION DATA/WEAR POINTS: The most critical part in this suspension is the auxiliary spring. A new auxiliary spring unloaded measures 3 3/8 at its maximum height and should be replaced when its unloaded height is 3 or less. EB Bar Pin Bushing Kit LP Bolster Spring Kit LP Auxiliary Spring Kit MS Auxiliary Shim TS38000 Bushing TS Bushing TT38000 Bushing TT Bushing - Page 21 - Available any length or 2-piece rods

22 - Page 22 -

23 Hendrickson HN Bar pin end bushings are used but there are no center bushings for the beams to pivot on. The traditional center bushing is replaced by 2 large bolster springs (4 per vehicle). Transverse torque rod is critical Check for wear periodically Check bolsters for cracks/debonds Replace if material cut 3 length or 1 in depth Replace if bond separation is >1 ½ deep Polyurethane material impervious to chemical attack The location of the debond may be a secondary failure and the location of the debond can help locate the source of the root cause. Failure analysis: LOCATION Debond at top plate Debond at lower plate POSSIBLE PRIMARY FAILURE POINT Check torque rods for bushing failure Check bar pin end bushings for failure - Page 23 -

24 - Continued - - Page 24 -

25 Hendrickson HN EB Bar Pin Bushing Kit HS11000 Jounce Stop LP Bolster Spring (2) LP Auxiliary Spring Kit TS38000 Bushing TT38000 Bushing TR Pc Female End TR Pc Male End TR Pc Male End - Page 25 -

26 Visit Click on Document/Product Spotlight to view/download a copy of the Hendrickson HN Product Spotlight - Page 26 -

27 Hendrickson Intraax/Vantraax These suspensions feature a tri-functional bushing. The tri functions these bushings serve are to control three road forces: Vertical forces absorbed by bushing to reduce stress on axle Horizontal movement during braking and acceleration Roll stability to maintain control while turning/trailer The alignment function (Quik-Align) is provided by the OE hardware pucks. ATRO s bushing in replacement of the OE bushing will still allow manipulation of the pucks to adjust alignment. For PB , PB and PB : The OE trifunctional bushing is slightly larger on the OD than ATRO s version (about 1/8 ). ATRO s version is molded nearer to the installed compressed size. For PB : The OE tri-functional bushing is significantly larger on the OD than ATRO s version (6 5/16 vs. 5 ½ ). The OE bushing is designed for considerable compression into the beam housing. ATRO s version is molded much nearer to the compressed size. ATRO s installation tools PT (for TFII or ATRO s PB ) and PT (for TFIII or PB ) will install/remove OE bushing and/or ATRO bushing. Just remove the alignment pins when installing/removing ATRO. Conversely, the OE tool can be used to install/remove both OE and ATRO; simply remove alignment pins from rear drive plate before attempting ATRO installation/removal. ATRO P/N BSHG QTY PB HARDWARE 2 Wear washers, 2 flat washers, 1 bolt, 1 locknut - Page 27 - OE KIT (Bushing) S (TFII) PB * 1 2 Wear washers S (TFII) PB ** 1 Alignment collars, bolt sleeve, bolt, nut A-6914 (TFII) PB wear washers, 4 flat washers, 2 bolts, 2 locknuts S (TFIII) *No exact OE cross reference. For ATRO customers who purchase hardware elsewhere. **Older version. Original version before OE released Quik-Align had thicker bolts. Bolt size is different than PB

28 - Continued - - Page 28 -

29 Hendrickson Intraax/Vantraax WEAR ITEMS: Tri-Functional bushing Mode of failure: bushing tube spacers melt, inner sleeve separated from rubber Cause: excessive movement of suspension arm vertically built up excessive heat Check to see if tires are out of balance or if shocks have failed. PB Pivot Bushing Kit PB Pivot Bushing Kit - Page 29 - PB Pivot Bushing Kit (set of 2) PT Installation Tool

30 - Page 30 -

31 Hendrickson Primaax Heavy-duty air suspension for vocational, severe-service and heavy-haul applications. Is approved for use by the OE for crane, dump, heavy-haul, logging, mining, ready-mix, oil field, tanker trucks and garbage haulers. Multiple versions of this suspension. Variations in design are usually in the shape of the hangers, length/location of the shocks or unique air springs. Overall design idea is the same. ATRO offers a full complement of bushings and torque rod options for Hendrickson s Primaax. The pivot bushing, PB , utilizes a low friction intermediate sleeve to ease rotation and improve resistance to wear. The OE s is used in Primaax, MaxAir and Twisted Sister. Though the bushings are direct cross-references, ATRO s PB is only for use in Hendrickson s Primaax suspensions (and its variations.) PB has a simple instruction guideline in the Instruction Sheets section under the Documents menu. Product Spotlight PS NP shows ATRO s full Primaax replacement part line and is available in the Product Spotlights section under the Documents menu at - Page 31 -

32 - Continued - - Page 32 -

33 WEAR AREAS: Hendrickson Primaax Frame hanger attachment area becomes oblong Usually caused by loose pivot bolt fasteners or overloading Check transverse torque rods for wear, too Torque rods bushing walks out of rod Longitudinal rods Check for improper alignment or worn bushings Transverse rods Check for incorrect axle alignment, incorrect pinion angle, incorrect frame hole location or axle bracket weld is off Worn bushings PB Pivot Bushing SU D-Pin Bushing TH Bushing TS38000 Bushing TS Bushing TS Bushing TT Bushing TR Pc Female End - Page 33 - TR Pc Male End

34 Visit Click on Document/Product Spotlight to view/download a copy of the Hendrickson Primaax Product Spotlight Visit Click on Document/Installation Sheets to view/download a copy of the Hendrickson PB Installation Sheet - Page 34 -

35 Hendrickson RS ATRO center bushings require thrust washers ATRO bushings have free-rotation *eases installation *zeroes out to ride height Polyurethane material impervious to chemical attack On the RS, ATRO s load pads are made of our proprietary low rebound (no-bounce) material to absorb shock and limit its transfer to the frame. To accomplish this with rubber, the OE traditionally offers 2 different part numbers of varying hardness for specific applications. ATRO s one part number will perform reliably in any application. BM Rebound Control Kit CB38011/12 Center Bushing Kit EB38000 Beam End Bushing EB Bar Pin Bushing Kit HC10000 Center Load Cushion HC20000 Load Cushion HV38000 Vertical Bushing TS38000 Bushing - Page 35 - Available any length or 2-piece rods

36 - Page 36 -

37 Hendrickson RT ATRO center bushings require thrust washers ATRO bushings have free-rotation eases installation zeroes out to ride height Polyurethane material impervious to chemical attack AK38200 Beam End Adapter Kit CB38011 Center Bushing Kit CB38012 Center Bushing Kit CT10000 Cross Tube EB38000 Beam End Bushing EB Bar Pin Bushing Kit TS38000 Bushing TR Pc Torque Rod, Female - Page 37 - TR Pc Torque Rod, Male

38 - Page 38 -

39 Hutch H/CH 7700/9700 ATRO offers: Cast or fabricated equalizers Equalizer kit includes hardware ATRO s torque rod bushings have retaining rims 2-piece design Wear items: Equalizer/bushings Torque rods/torque rod bushings ATRO benefit: ATRO equalizer kits include hardware *Equalizer Beams w/bushings **Equalizer Bushing Kits PL1119 Bushing TH Bushing Kit TR Fixed Length TR Adjustable Length *EQ , EQ , EQ , EQ ** EQ , EQ Page 39 -

40 - Page 40 -

41 International Corporate Air/IROS Similar in concept to the Freightliner FAS II and Peterbilt s New Low Air Leaf. The biggest concern with bonded bushings is the spring eye opens up and the bushing can walk out: With a bonded OE-style rubber bushing, the pin is not allowed to rotate, so the ENTIRE bushing can be forced to spin within the eye of the spring thus leading to the wallowed out spring eye. Bonded rubber bushings attempt to combat this with an inboard flanged end encased in a ring with detents for gripping the edge of the spring s eye. With ATRO s rotating bushing, the outer sleeve and urethane rotate around the fixed pin. ATRO spring eye bushing design (PB ): Outer sleeved is flanged to limit lateral travel Inner pin rotates rather than entire bushing spinning ATRO torque rod: The OE offers multiple torque rod options on this suspension. The OE standard can be replaced by ATRO s TR55-418C1 but the published options include nonrebushable rods, those rebushed with TS34000 bushings, or even tubular rods with jam bushings (ATRO s TS ) Inner pin rotates for easy installation easy to align bolt holes (TS34000 and TS38000) Rebushable PB Pivot Bushing (oversize version available) PL1146 Bushing - Page 41 - TS Bushing TR55-418C1

42 - Page 42 -

43 International Z Air Spring Suspension This suspension could be spec d with many different torque rod bushings: small jam bushings (PL1146), conventional size (TS38000/TT38000), non-rebushable. ATRO s TR replaces what appears to be the most popular spec d length, 18 1/8. This uses ATRO s small rod eye design with TS bushings. The Z Spring replaces the heavier paddle and adds to deflection as well as acting as the mount for the air spring. Wear Items: Torque rods/torque rod bushings Spring wear pad (WP55-290C1) Shocks PL1146 Bushing TR Small Eye TR71000 TR Pc 2 Pc Male End Male End TS34000 Bushing TS38000 Bushing TS Bushing WP55-290C1 Wear Pad - Page 43 -

44 - Page 44 -

45 Kenworth AirGlide 100 There are four torque rods - two transverse, two radial track rods. The radial rods (running the length of the vehicle) can be either 24 (TR ) for 52 axle spread or 25 (TR ) for 54 axle spread. The two transverse rods are both TR The OE rubber sway bar wrap bushing does not have tabs, but when the bushing is compressed in the housing, the rubber bulges out effectively forming side tabs. ATRO molds those side tabs into the part in the PL1008; the PL1184 is molded without tabs. The sway bar bushings are replaced with the TS The bushings are designed to withstand the extra heat generated from the high-frequency, low amplitude vibration (aka road noise ) the U-shaped sway bars encounter in service. PL1008 Air Ride Bushing TS38000 Bushing TT38000 Bushing TR TR TR Page 45 -

46 - Page 46 -

47 Kenworth AirGlide 200/400 AirGlide 200 can be retrofitted up to an AirGlide 400 ATRO s Technical Guidelines sheet TG discusses important installation points, identifies those parts in our kit which are optional and gives other recommended practices. It is available at under the Documents menu, Technical Bulletins section. Additional benefits found on Tech Bulletin TB in the Technical Bulletins section under the Documents menu on our website. The four upper torque rods are uniquely positioned in this suspension. This suspension combines the transverse and longitudinal torque rods into a dual rod, V configuration with the torque rods mounted vertically. Our TS bushing is a High Articulation bushing designed to withstand the conical motion required. It is the only ATRO torque rod bushing approved for use in OE aluminum rods. It features: Articulation voids to provide extra vertical motion Modified pin (compared to our standard TS38000 pin) ATRO s replacement torque rod is TR It features: Stronger, more durable steel rod than aluminum rod Forged steel rod eyes Heavy-walled steel shaft Sway bar bushings: TS38000 for heat build up from road noise (See AirGlide 100 section for technical details.) Sway bar kits: SW KIT (2 bushed bars + hardware) SW (1 bushed bar) - Page 47 -

48 PART NUMBER LOCATION HEAT TOLERANCE TS s only Normal TS38000 Sway Bar/Torque Leaf only Slightly Higher - Page 48 -

49 Kenworth AirGlide 380 Peterbilt FlexAir On a Kenworth it s branded as an AirGlide 380; on a Peterbilt this same suspension is branded as a Flex Air. The C-shaped spring link makes this suspension easily identifiable. ATRO offers the spring link bushings SU (straddle) and SU (hollow mount). There are six torque rods two transverse, two lower front, two lower rear. The front rods (TR ) are almost an inch shorter than the rear rods (TR ) but both front and rear have a straddle-hollow mount configuration. The two transverse rods (both are TR ) have a straddlestraddle configuration. High wear item: Transverse torque rods! All replacement torque rods on this suspension have the smaller 2 rod eye with ATRO s TS (straddle) and TH (hollow). These bushings have outer sleeves, the pins rotate, and the rods are rebushable with ATRO bushings only. To rebush the OE rod with 1 7/8 rod eyes, use ATRO s TS (straddle) and TH (hollow). SU Spring Link Bushing SU Spring Link Bushing TH Bushing TS Bushing TR Small Eye TR Small Eye - Page 49 - TR Small Eye

50 - Page 50 -

51 Mack Camelbacks ATRO load pads: Low rebound no bounce Chemically resistant Don t mix ATRO with others Wear items: Load pads Trunnion bushings Torque rod/torque rod bushings ATRO benefits: Specially formulated for this application, ATRO s proprietary polyurethane takes the bounce out and acts as a shock absorber. The significantly improved ride is immediately noticeable! This reduces cab damage and T-leaf breakage, too. Extended life load pad. Mack Trunnion Bushings Mack Load Pads Upper & Lower MS Insulator Spacer Block TM38000 Bushing TS38000 Bushing - Page 51 - Available any length or 2-piece rods

52 - Page 52 -

53 Peterbilt Air Leaf Eye casting bolted to the spring houses the pivot bushing (ATRO s PB , OE s 03AL1): PB is a spring eye bushing service kit that has bushings, sleeve, washers and hardware. The polyurethane components within this kit are PL1076 and PL1075 (2 each kit) and are also available separately. (PB is ½ longer than the original design Low Mount Air Leaf version, PB ) Tech Guidelines bulletin TG outlines recommended installation sequence for PB and is available at under the Documents menu, Technical Bulletins section. ATRO s torque rods (ATRO s TR , OE s ): Rebushable (OE standard is non-rebushable; rebushable options available) Rotating-pin for easy installation Heavy-duty bushing (OE standard bushing has smaller O.D.) Wear items: Spring eye pivot bushing Torque rod/torque rod bushings Comparison: MFR ROD BUSHING REBUSH- ABLE ROTATING OE 1 1/8" O.D. TS34000 (2 17/32") Varies No ATRO 1 1/4" O.D. TS38000 (2 3/4") Yes Yes PB Air Leaf Bushing Kit PL1026 Shock Bushing PL1075 Air Leaf Bushing PL1076 Beam End Washer TR Page 53 - TS34000 Bushing

54 - Page 54 -

55 Peterbilt Air Trac ATRO s torque rods for upper transverse rod replacement (ATRO s TR , OE s ): Rebushable Rotating-pin for easy installation Heavy-duty bushing (OE standard bushing has smaller O.D.) If rebushing ATRO s TR , use ATRO s TS38000 If rebushing OE/aftermarket rods, use ATRO s TS34000 ATRO s torque rods for lower rod replacement: The lower rods come in two versions. ATRO s TR is a direct OE replacement - both use the larger straddle bushing (TS38000). ATRO s TR option is also a direct replacement to the OE offering. Note: the bushings within the same rod differ: the axle bracket end has a ¾ bolt but the frame side has 5/8 bolt. ATRO s rod has a TS38000 in one end and a TS38750 in the other. Rebushable Rotating-pin for easy installation ATRO also offers the spring roller, SU , or the complete spring roller kit, SU ATRO pricing on the kit includes the urethane and steel rollers PLUS the bolt, nut and washer. Wear items: Torque rod/torque rod bushings Spring roller PL1026 Shock Bushing SU Spring Roller SU Spring Roller Kit TS34000 Bushing TS38000 Bushing TS38750 Bushing - Page 55 - TR , TR TR

56 - Page 56 -

57 Peterbilt Low Mount Air Leaf Eye casting bolted to the spring houses the pivot bushing (ATRO s PB , OE s 03AL2): PB is a spring eye bushing service kit that has bushings, sleeve, washers and hardware. The polyurethane components within this kit are PL1076 and PL1189 (2 each kit) and are also available separately. Tech Guidelines bulletin TG outlines recommended installation sequence for PB and is available at under the Documents menu, Technical Bulletins section. ATRO s torque rods (ATRO s TR , OE s ): Rebushable (OE standard is non-rebushable) Rotating-pin for easy installation Heavy-duty bushing (OE standard bushing has smaller O.D. Wear items: Spring eye pivot bushing Torque rod/torque rod bushings Comparison: MFR ROD BUSHING REBUSH- ABLE ROTATING OE 1 1/8" O.D. TS34000 (2 17/32") No No ATRO 1 1/4" O.D. TS38000 (2 3/4") Yes Yes PB Air Leaf Bushing Kit PL1076 Beam End Washer PL1189 Spring Eye Bushing TR Page 57 - TS34000 Bushing

58 - Page 58 -

59 Peterbilt New Low Air Leaf Similar in concept to the Freightliner FAS II and the International Corporate Air/IROS. The biggest concern with bonded bushings is the spring eye opens up and the bushing can walk out: With a bonded OE-style rubber bushing, the pin is not allowed to rotate, so the ENTIRE bushing can be forced to spin within the eye of the spring thus leading to the wallowed out spring eye. Bonded rubber bushings attempt to combat this with an inboard flanged end encased in a ring with detents for gripping the edge of the spring s eye. With ATRO s rotating bushing, the outer sleeve and urethane rotate around the fixed pin. ATRO spring eye bushing design (PB ): Outer sleeved is flanged to limit lateral travel Inner pin rotates rather than entire bushing spinning ATRO torque rod: Uses ATRO torque rod TR This is a smalleyed rod with TS in each end. The bushing in these rods is a TS it will not fit OEM or other aftermarket rods. To rebush OE rod or other aftermarket rod, use ATRO s TS Inner pin rotates for easy installation easy to align bolt holes (TS only.) Rebushable PB Pivot Bushing - Page 59 - TR

60 - Page 60 -

61 High-Temperature Underhood Mounts ATRO recently launched its newest breakthrough product line High-Temperature motor mounts and underhood components. ATRO is one of several companies releasing new products that can tolerate higher temperatures. So, why has under hood heat become such an issue? EPA Tier 3 emission standards, in effect since , mandate that diesel engine manufacturers reduce emission levels of NOx (nitrogen oxides). The ripple effect created by the necessary underhood changes gets complicated because each solution creates new problems in another area. The most significant is only beginning to be recognized: elevated under hood temperatures. Here s the big picture short version: New engine designs use EGR to control NOx emissions by recirculating some of the exhaust gases back into the combustion chamber. Due to the mix of exhaust with air entering the combustion chamber, there is less oxygen than if it were just air. With less oxygen it doesn t burn as hot and at a lower temperature NOx don t get a chance to form in the first place thus lower NOx emission levels. But here s the kicker - the exhaust is cooled before it is reintroduced to the combustion chamber. Engine manufacturers have always used the basic rule of thumb that the energy output of the engine is equally divided with 1/3 going to power, 1/3 to exhaust and 1/3 used to cool the engine. In these new engine systems, the cooling system is now over-burdened by 15 30% because it must additionally cool the exhaust gas before it can recirculate for round two. - Page 61 -

62 Do not mix standard mounts and HT mounts of the same part number if the standard mounts are affected by heat and melt (or soften and compress), the full weight of the engine/tranny will fall on the unaffected HT mount. ONE EXCEPTION to this mixing rule is on the Kenworth mounts KT and KT HT (or KT HT which includes hardware.) In this one application, ATRO offers the front mounts in HT but not the rear mounts. The front mounts are susceptible to heat-related failure but the rear mounts show no such track. The material used in the rear mounts address vibration isolation specifically the added expense of an HT modification is not necessary. - Page 62 -

63 Chalmers Freightliner FASII Hendrickson Haulmaax Hendrickson HN Hendrickson Intraax Hendrickson Primaax Hendrickson RS Hendrickson RT - Page 63 -

64 Hutchens International Corp Air/IROS Kenworth AirGlide 100 Kenworth AG380/PB FlexAir Kenworth AirGlide 400 Mack Camelback Peterbilt Air Leaf Peterbilt Air Trac - Page 64 -

65 Peterbilt Low Air Leaf Peterbilt New Low Air Leaf - Page 65 -

66 - Page 66 -