AXLE APPLICATION GUIDELINES LOGGING TP-9441LG4 REVISED 4-98
TP-9441LG4 Logging Vocational Definition: Vehicles (usually Tractor/Trailer combinations) used to transport logs, pulp and paper products between logging sites and/or mills (Chip Haulers included). Vehicles are specially designed for high loads. High horsepower engines are typically used in this vocation. Two duty cycles are considered: light (0-8% grades) on-road service only and severe (0-20% grades) with on-road service for 90% of the time and off-road service for 10% of the time. Greater than three miles average between stops/starts is also considered normal. Retarders are considered typical in this vocation (Duty I max. of 1 retarder; Duty II max. of 2 retarders). This vocation is defined as loaded going and empty return (30-40% GCW). Logging Vehicles Include: Chip Hauler Log Hauling Tractor/Trailer with Jeeps Tractors with Pole Trailers Michigan Special Log Haul
Intended Use of This Guideline This document addresses approvable GAW, Axle Torque and GVW/GCW Ratings for Meritor Axles used in the Logging vocation (U.S. and Canada only). Conditions for Approval Axles are approved for use in the vocation covered by this document, when the axles meet the guidelines for STRUCTURE (Pages 4-9), TORQUE (Pages 10-11), and GROSS VEHICLE or GROSS COMBINATION WEIGHT (Pages 12-13), as described by this publication. IMPORTANT NOTES (Pages 14-15) are considered to be part of the axle approval. For any questions concerning this document (interpretations and calculations) or for loadings, configurations or duty cycles outside the parameters of this guideline, contact Meritor Axle Engineering by telephone, by FAX or in writing to the address shown below, using the Meritor Axle Components Application form RA-4901-B-040. MERITOR AUTOMOTIVE, INC. AXLE ENGINEERING 2135 W. MAPLE RD. TROY, MI 48084 PHONE: 800-535-5560 FAX: 248-435-3545 Warranty Meritor Axle Products which are included in this guideline and are operated within the vocational limitations set forth by this document are covered by Meritor s industry competitive warranty. For complete details (and specific coverage) refer to Meritor s Warranty Publication (SP-95155). Consult Meritor on questions concerning warranty coverages and application approvals for products used outside of these published guidelines. NOTE: Axle applications for tire sizes, tracks, mounting centers, other front axle KPIs, other Meritor axle models, engine/transmission torques beyond those listed, or GVW/GCW other than as shown within this AXLE GUIDELINE may still be approvable. Contact Meritor Axle Engineering for possible approval. TP-9441LG4 Page 1
What Is Logging Logging Vocation Axle Guidelines Movement of logs, chips and pulp between logging sites and/or mills. DUTY I: Operation on road surfaces made of concrete, asphalt, maintained gravel, crushed rock, hard packed dirt or other similar surfaces. DUTY II: Operation on road surfaces made of concrete, asphalt, maintained gravel, crushed rock, hard packed dirt or other similar surfaces for 90% of the time and into sandy or muddy job sites for 10% of the time. High horsepower engines are typically used in this vocation. Greater than 3 miles average between starting and stopping. Multiple retarders typically used (engine brake, exhaust brake hydraulic transmission, or chassis mounted electromagnetic). However, vehicles equipped with more than 2 retarders are not approvable with this Guideline. See IMPORTANT NOTE 6. NOTE: Increases in grades and/or numbers of starts/stops will have a notable influence on the service life of the driving axle(s). Types of Vehicles 6x4 Tractors and trucks with full trailers (Michigan Specials are included in this axle guideline). Duty Cycles Duty I: Duty II: DUTY LOGGING LOADING (Refer to Pages 12 & 13) GRADES I II With maximum of 1 retarder. With maximum of 2 retarders. 100% Load Going/Empty Return 100% Load Going/Empty Return 8% Max 20% Max Page 2 TP-9441LG4
Meritor Axle Models... nominal Gross Axle Weight Ratings FRONT STEER TANDEM REAR Model lbs Model lbs FF-941 12000 RT-40-145/P/A 40000 FF-942 13200 RT-40-160/P/A 40000 FF-943 12000 RT-46-160/P/A* 46000 FF-944 13200 RT-46-164/P/A 46000 FF-961 12000 RT-50-160/P/A 50000 FF-966 12000 RT-52-185 52000 FF-967 13200 RT-52-380 52000 FG-941 14600 RT-58-185 58000 FG-943 14600 RT-58-380 58000 FL-941 20000 RT-70-380 70000 FL-943 20000 OPTION: A = Aluminum Carrier P = Pump (Forward Carrier) Consult Meritor Publication TP-7824 for additional dimensional information. *RT-46-160 not approvable for use in Canada for this vocation. The RT-46-164 is required. TP-9441LG4 Page 3
Front Non-Drive Steer and Rear Drive Axle Structural Guides The following items determine the structural requirements of the axle: The load capacities (Gross Axle Weight Rating) are compared against the TRACK using the following parameters: 1. The maximum value of the Static Loaded Radius (SLR) of the tires. 2. Suspension Mounting Centers (SMC). 3. The standard front axle King Pin Intersection (KPI) dimensions. If single tires are used, the TRACK is measured (at the ground) from the center of one tire to the center of the opposite tire. If dual tires are used, the TRACK is measured from the center of the dual tires to the same point on the opposite side. The Gross Axle Weight Rating, as a function of SLR, and the axle SMC must meet the specifications of the graphs. NOTE: Axle applications for tire sizes, tracks, mounting centers, other front axle KPIs and other Meritor axle models not shown within this AXLE GUIDELINE may still be approvable. Contact Meritor Axle Engineering for possible approval. Page 4 TP-9441LG4
Front Non-Drive Steer Axles Structural Ratings The approvable area is located on or below each structural curve as follows: 22000 STRUCTURAL RATINGS 22.5" MAX SLR 31.88" TO 36.00" SMC GAWR (LBS) 20000 FL-941/943 18000 FL-941 AXLE 68.50" KPI FL-943 AXLE 68.83" KPI ALL OTHERS 69.00" KPI 16000 FG-941/943 14000 FF-942/944/967* 12000 FF-941/943/961*/966* 10000 8000 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" 84" 85" 86" 87" 88" 89" 90" TRACK (INCHES) AXLE MODEL FF-941/943/961*/966 FF-942/944/967* FG-941/943 FL-941/943 *FF-961/966/967 AXLES ONLY 32.50" TO 35.00" SMC TP-9441LG4 Page 5
Tandem Rear Drive Axles Structural Ratings The approvable area is located on or below each structural curve as follows: 42000 STRUCTURAL RATINGS 20.7" MAX SLR 35.88" AND 40.25" MIN SMC GAWR (LBS) RT-40-145WT (14.3) 40000 38000 RT-40-145 (11.0) 36000 RT-40-145 (9.5) 34000 32000 35.88" MIN SMC = SOLID LINES 40.25" MIN SMC = DASHED LINES 30000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) AXLE MODEL WALL THICKNESS (MM) RT-40-145 (9.5) RT-40-145 (11.0) RT-40-145WT (14.3) GAWR (LBS) 42000 STRUCTURAL RATINGS 23.4" MAX SLR 35.88" AND 42.25" SMC RT-40-160WT (16.0) 35.88" & 40.25" MIN SMC 40000 38000 RT-40-160 (11.0) 36000 35.88" MIN SMC = SOLID LINES 34000 40.25" MIN SMC = DASHED LINES 32000 30000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) AXLE MODEL WALL THICKNESS (MM) FF-941/943/961*/966 FF-942/944/967* See IMPORTANT NOTES 4 and 11 for additional information (Pages 14 and 15). WT designates Wide Track Axle Housing Option. Page 6 TP-9441LG4
Tandem Rear Drive Axles Structural Ratings The approvable area is located on or below each structural curve as follows: 48000 STRUCTURAL RATINGS 23.4" MAX SLR 35.88" MIN SMC GAWR (LBS) 46000 44000 RT-46-164 (16.0) 42000 40000 RT-46-160 (12.7) 38000 36000 RT-46-164WT (16.0) 34000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) AXLE MODEL WALL THICKNESS (MM) RT-46-160 (12.7) RT-46-164 (16.0) RT-46-164WT (16.0) GAWR (LBS) 48000 STRUCTURAL RATINGS 23.4" MAX SLR 40.25" MIN SMC RT-46-164WT (16.0) 46000 44000 RT-46-160 (12.7) & RT-46-164 (16.0) 42000 40000 38000 36000 34000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) AXLE MODEL WALL THICKNESS (MM) RT-46-160 (12.7) & RT-46-164 (16.0) RT-46-164WT (16.0) See IMPORTANT NOTES 4 and 11 for additional information (Pages 14 and 15). WT designates Wide Track Axle Housing Option. TP-9441LG4 Page 7
Tandem Rear Drive Axles Structural Ratings The approvable area is located on or below each structural curve as follows: 52000 STRUCTURAL RATINGS 23.4" MAX SLR 35.88" MIN SMC GAWR (LBS) 50000 48000 46000 44000 42000 40000 35.88" MIN SMC = SOLID LINES 40.25" MIN SMC = DASHED LINES 38000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) RT-50-160 (16.0) AXLE MODEL WALL THICKNESS (MM) RT-50-160WT (16.0) RT-50-160 (16.0) RT-50-160WT (16.0) 52000 STRUCTURAL RATINGS 23.4" MAX SLR 40.25" MIN SMC GAWR (LBS) 50000 48000 46000 44000 42000 40000 RT-50-160 (16.0) RT-50-160WT (16.0) 38000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) AXLE MODEL WALL THICKNESS (MM) RT-50-160 (16.0) RT-50-160WT (16.0) See IMPORTANT NOTE 11 for additional information (Page 15). WT designates Wide Track Axle Housing Option. Page 8 TP-9441LG4
Tandem Rear Drive Axles Structural Ratings The approvable area is located on or below each structural curve as follows: 54000 STRUCTURAL RATINGS 23.4" MAX SLR 35.50" MIN SMC GAWR (LBS) 52000 RT-52-185WT/380WT (14.3) 50000 48000 46000 RT-52-185/380 (14.3) 44000 42000 40000 38000 36000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) AXLE MODEL WALL THICKNESS (MM) RT-52-185/380 (14.3) RT-52-185WT/380WT (14.3) GAWR (LBS) STRUCTURAL RATINGS 23.4" MAX SLR 35.50" AND 41.50" MIN SMC 72000 70000 68000 RT-70-380 STD & WT (16.8) 66000 64000 62000 60000 58000 56000 54000 35.50" MIN SMC = SOLID LINES RT-58-185/380 STD & WT (14.3) 52000 41.50" MIN SMC = DASHED LINES 50000 48000 71" 72" 73" 74" 75" 76" 77" 78" 79" 80" 81" 82" 83" TRACK (INCHES) See IMPORTANT NOTE 11 for additional information (Page 15). WT designates Wide Track Axle Housing Option. AXLE MODEL WALL THICKNESS (MM) RT-58-185/380 (14.3) STD & WT RT-70-380 (16.8) STD & WT TP-9441LG4 Page 9
Axle Torque Ratings Logging Vocation Axle Guidelines The following formula is to be used to determine CALCULATED INPUT TORQUE TO AXLE. CALCULATED INPUT TORQUE TO AXLE = T x N x R where T = Maximum Gross Engine Torque (LB-FT) N = Lowest Transmission Forward Gear Ratio R = 1.0 for no Retarder or one Retarder = 1.25 for a maximum of two Retarders Maximum engine torques greater than 2050 lb-ft (1650 LB-FT for RT-145) are not approved by this Axle Guideline. Contact Meritor Axle Engineering for possible approval. Calculated values of input torque to axle which are outside the limits of the Axle Torque Ratings shown within this Axle Guideline may be approvable (i.e., Torque Limiting Devices). Contact Meritor Axle Engineering for possible approval. For vehicles with more than two retarders, see IMPORTANT NOTE 6. The chart on Page 11 is to be used to determine axle torque limits approved for the identified Meritor axle models by available ratio. See IMPORTANT NOTE 11 for additional information (Page 15). Page 10 TP-9441LG4
Axle Torque Ratings For Logging Axle MAXIMUM ALLOWABLE INPUT TORQUE TO AXLE (LB-FT) RT-145 RT-16x RT-185 RT-380 Ratios 3.07 xx 30,000 x x 3.21 xx 30,000 x x 3.42 23,000 30,000 x x 3.58 22,100 30,000 x x 3.73 22,100 30,000 30,000 x 3.91 22,100 30,000 x x 4.10 22,100 30,000 30,000 x 4.30 x 30,000 30,000 x 4.33 21,800 x x x 4.56 x 30,000 30,000 x 4.63 20,400 x x x 4.88 18,000 x x x 4.89 x 30,000 30,000 x 5.29 16,600 x x x 5.38 x 26,200 30,000 x 5.52 x x x 30,000 5.63 x 23,000 x x 5.86 12,200 x x x 6.07 x x x 30,000 6.14 xx 20,400 24,000 x 6.37 x x x 27,200 6.43 xx 17,800 x x 6.75 x x x 26,200 6.83 xx 17,800 20,400 x 7.17 xx 16,000 18,400 x 7.24 x x x 21,200 7.83 x x x 20,400 9.14 x x x 16,000 10.12 x x x 13,400 10.62 x x x 12,200 NOTES: 1) Axle torque ratings charted above are to be used only with guidelines for Logging Vocation. 2) Calculated Input Torque to Axle (per formula) must be less than Maximum Allowable Input Torque to Axle (per chart). 3) Maximum engine torques greater than 2050 lb-ft (1650 lb-ft for RT-145) are not approved by this guideline. Contact Meritor Axle Engineering for possible approval. 4) x = Ratio not available. 5) xx = Contact Meritor Axle Engineering for possible approval. TP-9441LG4 Page 11
GVW/GCW Ratings Logging Vocation Axle Guidelines These charts list maximum GVW/GCW for Meritor axle models (by ratio) for the two duty cycles outlined in this AXLE GUIDELINE. MAX GVW/GCW S (LBS) BY AXLE BY RATIO DUTY I (8% MAX GRADES) 100% LOAD GOING/EMPTY RETURN Axle Model RT-145 RT-16x RT-185 Hypoid Ratios 3.07 xx 164,000 x 3.21 xx 164,000 x 3.42 100,000 164,000 x 3.58 100,000 164,000 x 3.73 100,000 164,000 180,000 3.91 100,000 164,000 x 4.10 100,000 164,000 170,000 4.30 x 160,000 170,000 4.33 100,000 x x 4.56 x 160,000 170,000 4.63 100,000 x x 4.88 90,000 x x 4.89 x 130,000 164,000 5.29 90,000 x x 5.38 x 130,000 164,000 5.63 x 130,000 x 5.86 70,000 x x 6.14 xx 100,000 140,000 6.43 xx 90,000 x 6.83 xx 80,000 120,000 7.17 xx 80,000 110,000 NOTES: 1) x = Ratio not available. 2) xx = Contact Meritor Axle Engineering for possible approval. 3) GVW/GCW limits beyond those shown within this AXLE GUIDELINE may be approvable. Contact Meritor Axle Engineering for possible approval. See IMPORTANT NOTE 9 for additional information (Page 15). Page 12 TP-9441LG4
GVW/GCW Ratings (Cont d.) MAX GVW/GCW S (LBS) BY AXLE BY RATIO DUTY II (20% Max Grades) 100% LOAD GOING/EMPTY RETURN Axle Model RT-16x RT-185 RT-380 Hypoid Ratios 3.07 140,000 x x 3.21 140,000 x x 3.42 140,000 x x 3.58 140,000 x x 3.73 140,000 164,000 x 3.91 130,000 x x 4.10 130,000 164,000 x 4.30 130,000 150,000 x 4.56 130,000 150,000 x 4.89 120,000 150,000 x 5.38 110,000 150,000 x 5.52 x x 164,000 5.63 110,000 x x 6.07 x x 164,000 6.14 90,000 130,000 x 6.37 x x 160,000 6.43 90,000 x x 6.75 x x 160,000 6.83 80,000 110,000 x 7.17 70,000 100,000 x 7.24 x x 150,000 7.83 x x 150,000 9.14 x x 140,000 10.12 x x 100,000 10.62 x x 90,000 NOTES: 1) x = Ratio not available. 2) xx = Contact Meritor Axle Engineering for possible approval. 3) GVW/GCW limits beyond those shown within this AXLE GUIDELINE may be approvable. Contact Meritor Axle Engineering for possible approval. See IMPORTANT NOTE 9 for additional information (Page 15). TP-9441LG4 Page 13
Important Notes Logging Vocation Axle Guidelines 1. The following optional components are approved by this AXLE GUIDELINE. All options may not be available on all axle models: a. Driver-Controlled Differential Lock (DCDL) b. ABS c. Oil Pump d. Advanced Lube 2. The use of NoSPIN differentials in any single or tandem rear drive axle will result in the exclusion of axle shafts from warranty considerations. Certain other carrier components will also be excluded from warranty considerations if their failure is deemed the result of a NoSPIN failure or malfunction. Depending on axle loading, the NoSPIN can cause all differential torque to be directed to one axle shaft causing overload (and potential failure). NoSPIN is a product of Tractech, a Titan Wheel International Company. 3. For approval of Meritor Transmission, Clutch, Driveline, Retarders, Brake, Wheel End, Trailer Axle and all other components contact the appropriate Meritor engineering function: 800-535-5560. 4. For certain Suspension models, Meritor requires the use of an increased housing wall thickness. See Meritor Product Information Letter No. 134 or contact Meritor Axle Engineering for clarification. 5. For details on Meritor s Advanced Lubrication Program consult Meritor Technical Publication TP-9303 or Maintenance Manual MM No. 1. 6. Vehicles equipped with more than two Retarders of any type (engine brake, exhaust brake, hydraulic transmission, chassis mounted or axle mounted electromagnetic) must be approved by Meritor as well as the manufacturers of the selected retarders. Contact Meritor Axle Engineering for possible approval. Vehicles with two or less retardation devices are approvable by this Axle Guideline. 7. Vehicles using Liftable (Tag or Pusher) axles within this vocation may be approvable. Contact Meritor Axle Engineering for possible approval. 8. Meritor Automotive Axle Application Approval, with respect to the Suspension selected, is limited to the location of the suspension attaching positions relative to those parameters (track, tire, mounting centers, etc.) specified. Attachment to the axle housing assembly and durability of the axle housing assembly as a result of suspension loadings on the housing, is the responsibility of the OEM. Meritor assumes responsibility of the bracket integrity and attachment only if: a. The brackets are attached by Meritor or, b. Meritor has established a prior agreement with the OEM. Page 14 TP-9441LG4
Important Notes (Cont d.) 9. It is the responsibility of the OEM and/or the dealer to accurately convey all approved axle loading information to the Body Builder if the chassis is sold as incomplete. It is also the responsibility of the final vehicle builder to insure the assigned tagged values for GAWR and GVW/GCW do not exceed those limits approvable by this vocational guideline. 10. The OEM has the responsibility to determine Steering Axle Specifics (Maximum Turn Angle, Tie Rod Arm Selection, Steering Arm Selection, Geometry Limits, etc.). Meritor Axle Engineering can assist the OEM with these parameters. 11. Drive axles configured with single tires may require special consideration. Aggressive High Mobility single tires of on/off-road and agricultural tread designs are capable of transmitting higher than normal wheel torque into the ground surface. This can result in axle components being stressed beyond allowable limits. If single tires are utilized with other than strict On-Highway tread designs, Meritor Axle Engineering should be consulted for special consideration of the application. 12. The Driver-Controlled Differential Lock option, when available, is highly recommended for all logging operations where vehicles operate in off-road areas. 13. Vehicle testing of any nature voids the warranty on Meritor axles. Meritor does not approve of automatic transmission stall testing and does not warrant components against these procedures. TP-9441LG4 Page 15
For more information, dial our toll-free number: 800-535-5560 The entire family of Meritor axles is an integral member of Drivetrain Plus TM by Meritor, the industry s most complete drivetrain. Page 16 Meritor Heavy Vehicle Systems, LLC 2135 West Maple Road Troy, MI 48084 U.S.A. 800-535-5560 www.meritorauto.com Information contained in this publication was in effect at the time the publication was approved for printing and is subject to change without notice or liability. Meritor Heavy Vehicle Systems, LLC, reserves the right to revise the information presented or discontinue the production of parts described at any time. Copyright 1998 TP9441LG4 Meritor Automotive, Inc. Printed in the USA Revised 4-98 All Rights Reserved Please Recycle 16579/Meritor TP-9441LG4