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© Goodheart-Willcox Co. , Inc. 1 Permission granted to reproduce for educational use only.

Chapter 12 Chapter 1 Drive Shaft Assembly Construction and Operation © Goodheart-Willcox Co. , Inc. 2 Permission granted to reproduce for educational use only.

Objectives Explain the purpose of a drive shaft assembly. List the major parts of a typical drive shaft assembly. Explain the function and operation of a slip yoke. Explain the function and operation of a universal joint. © Goodheart-Willcox Co. , Inc. 3 Permission granted to reproduce for educational use only.

Objectives Name and describe different types of universal joints. Discuss Hotchkiss drive and torque-tube drive. Describe the function of a center support bearing in a two-piece drive shaft. Briefly explain the concept of drive shaft assembly angles. © Goodheart-Willcox Co. , Inc. 4 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Drive shaft assembly (driveline) transfers power between transmission and rear axle assembly Drive shaft assembly consists of: Slip yoke Front universal joint Drive shaft Rear universal joint © Goodheart-Willcox Co. , Inc. 5 Permission granted to reproduce for educational use only.

Drive Shaft Assembly (Cont. ) (General Motors) © Goodheart-Willcox Co. , Inc. 6 Permission granted to reproduce for educational use only.

Drive Shaft Assembly (Cont. ) Slip yoke connects to transmission output shaft Rear universal joint connects to differential through differential pinion yoke or flange Balance weights reduce vibration © Goodheart-Willcox Co. , Inc. 7 Permission granted to reproduce for educational use only.

Drive Shaft Assembly (Cont. ) (Ford) © Goodheart-Willcox Co. , Inc. 8 Permission granted to reproduce for educational use only.

Drive Shaft Assembly (Cont. ) Drive shafts come in many sizes Length is measured from center of each yoke hole on drive shaft ends (General Motors) © Goodheart-Willcox Co. , Inc. 9 Permission granted to reproduce for educational use only.

Drive Shaft Assembly (Cont. ) On late-model vehicles, front and rear axles move to keep chassis level On rear-wheel drives, rear axle housing and both rear wheels move up and down in relation to chassis Suspension system connects rear axle assembly to chassis © Goodheart-Willcox Co. , Inc. 10 Permission granted to reproduce for educational use only.

Drive Shaft Assembly (Cont. ) Drive shaft angle and length must change to compensate for rear axle assembly movement Flexible joints allow drive shaft assembly to flex or bend as rear axle assembly moves © Goodheart-Willcox Co. , Inc. 11 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Power Flow Transmission to slip yoke Slip yoke to front universal joint and into drive shaft Drive shaft into rear universal joint Rear universal joint into rear axle assembly © Goodheart-Willcox Co. , Inc. 12 Permission granted to reproduce for educational use only.

Drive Shaft Drive shaft, or propeller shaft, is central part of drive shaft assembly Universal joints and other parts are attached to it Drive shaft consists of steel tube with yokes welded or pressed on each end Shaft is balanced when manufactured © Goodheart-Willcox Co. , Inc. 13 Permission granted to reproduce for educational use only.

Slip Yoke Slip yoke Used where drive shaft assembly enters rear of transmission Slides on transmission output shaft whenever rear axle assembly moves (Ford) © Goodheart-Willcox Co. , Inc. 14 Permission granted to reproduce for educational use only.

Slip Yoke (Cont. ) Steel tube with yoke at one end Yoke attaches to front universal joint Internal part of tube is splined May have damper (weight) to absorb vibration (Ford) © Goodheart-Willcox Co. , Inc. 15 Permission granted to reproduce for educational use only.

Universal Joints Universal joints (U-joints) are swivel connections, or couplings, that allow drive shaft assembly to transmit power smoothly and constantly Two basic types: Cross-and-roller Constant-velocity © Goodheart-Willcox Co. , Inc. 16 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints Cross-and-roller U-joint Used on most rear-wheel drives Sometimes called Cardan U-joint or conventional U-joint © Goodheart-Willcox Co. , Inc. 17 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Center cross (spider) Four cups containing needle bearings Cups are machined to fit into: Cup seals keep grease in cup and prevent entry of dirt and water Drive shaft yokes Slip yoke Differential pinion yoke (General Motors) © Goodheart-Willcox Co. , Inc. 18 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) (General Motors) © Goodheart-Willcox Co. , Inc. 19 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Some U-joints can be greased Some U-joints are sealed at factory and cannot be greased unless disassembled (Chrysler) © Goodheart-Willcox Co. , Inc. 20 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Cups may be held in yokes in different ways (Dana) © Goodheart-Willcox Co. , Inc. 21 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Some vehicles use injected plastic to hold cups in place (Dana) © Goodheart-Willcox Co. , Inc. 22 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Larger vehicles may use more complex U-joints (Arvin. Meritor) © Goodheart-Willcox Co. , Inc. 23 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Conventional U-joint is almost always driving at an angle, causing drive shaft speed to rise and fall twice for every revolution Range of speed fluctuation increases as joint angle increases © Goodheart-Willcox Co. , Inc. 24 Permission granted to reproduce for educational use only.

Cross-and-Roller U-Joints (Cont. ) Fluctuation in drive shaft speed Created at front U-joint Canceled at differential pinion yoke by rear U-joint When equal angles are formed by U-joint at transmission and drive shaft and U-joint at drive shaft and rear axle Canceled if U-joints are aligned in phase © Goodheart-Willcox Co. , Inc. 25 Permission granted to reproduce for educational use only.

CV Joints Constant-velocity U-joints (CV joints) Provide extremely smooth power transfer Are more complicated than conventional U -joints Are used by larger rear-wheel drive vehicles to further reduce vibration © Goodheart-Willcox Co. , Inc. 26 Permission granted to reproduce for educational use only.

CV Joints (Cont. ) Double Cardan U -joint Vibration forces are cancelled within center yoke (General Motors) © Goodheart-Willcox Co. , Inc. 27 Permission granted to reproduce for educational use only.

CV Joints (Cont. ) Ball-and-trunnion U-joint Not used on modern vehicles Separate slip yoke not needed © Goodheart-Willcox Co. , Inc. 28 Permission granted to reproduce for educational use only.

CV Joints (Cont. ) Rzeppa joint Ball bearings held by slotted cross assembly Ball bearings move up and down on cross as torque is transmitted through them Transmits power through changing angles (Dana) © Goodheart-Willcox Co. , Inc. 29 Permission granted to reproduce for educational use only.

CV Joints (Cont. ) Tripod joint Resembles ball-and-trunnion U-joint, but uses three-pointed cross pin Often used as inner bearing on front-wheel drives Sometimes used on drive axles of rearwheel drives with independent rear suspension © Goodheart-Willcox Co. , Inc. 30 Permission granted to reproduce for educational use only.

Differential Pinion Yoke Differential pinion yoke Connects to drive pinion gear in rear axle assembly Has internal splines that fit external splines on drive pinion gear shaft Held to shaft by large locknut © Goodheart-Willcox Co. , Inc. 31 Permission granted to reproduce for educational use only.

Differential Pinion Yoke (Cont. ) Differential pinion flange, or companion flange Two-piece yoke joined by mating flanges One flange holds rear U-joint, other connects to pinion gear (Ford) © Goodheart-Willcox Co. , Inc. 32 Permission granted to reproduce for educational use only.

Classes of Drive Shaft Assemblies Hotchkiss drive Used almost exclusively in late-model, rear -wheel vehicles Torque-tube drive Used on some makes of vehicles for many years, but now uncommon © Goodheart-Willcox Co. , Inc. 33 Permission granted to reproduce for educational use only.

Hotchkiss Drive Hotchkiss drive Used with rear leaf springs Salsbury drive Used with coil springs (Fiat) © Goodheart-Willcox Co. , Inc. 34 Permission granted to reproduce for educational use only.

Hotchkiss Drive (Cont. ) Variation of Hotchkiss drive: Constant-velocity U-joint is used Slip yoke is at rear of shaft One spline is larger than others (Ford) © Goodheart-Willcox Co. , Inc. 35 Permission granted to reproduce for educational use only.

Torque-Tube Drive Torque-tube drive is designed to control rear-end torque Drive shaft connects to transmission output shaft through U-joint Other end of shaft connects to drive pinion gear through coupling or splined connection U-joint at only one end © Goodheart-Willcox Co. , Inc. 36 Permission granted to reproduce for educational use only.

Torque-Tube Drive (Cont. ) Drive shaft assembly can flex only at U -joint between transmission and drive shaft Rear axle assembly moves up and down in arc as it pivots about U-joint Distance between transmission and rear axle assembly is always the same, so no slip yoke is needed © Goodheart-Willcox Co. , Inc. 37 Permission granted to reproduce for educational use only.

Two-Piece Drive Shaft Two-piece drive shaft Two drive shafts • Steel tubes with yokes on all four ends Three universal joints • Identical to those on one-piece drive shaft Drive shaft assembly angles are reduced at each U-joint, reducing vibration © Goodheart-Willcox Co. , Inc. 38 Permission granted to reproduce for educational use only.

Two-Piece Drive Shaft (Cont. ) © Goodheart-Willcox Co. , Inc. 39 Permission granted to reproduce for educational use only.

Two-Piece Drive Shaft (Cont. ) Center support bearing keeps drive shafts aligned Slip yoke usually installed behind support bearing Some designs have two slip yokes (Fiat) © Goodheart-Willcox Co. , Inc. 40 Permission granted to reproduce for educational use only.

Two-Piece Drive Shaft (Cont. ) Two-piece drive shafts: Were used when vehicle frame design prevented use of single drive shaft Were discontinued during 60 s and 70 s except on large trucks and some long-bed pickups Became common again with increased popularity of large SUVs © Goodheart-Willcox Co. , Inc. 41 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Angles All rotating parts have axial centerline, or rotational axis When rotating parts are coupled together, centerlines must be closely matched © Goodheart-Willcox Co. , Inc. 42 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Angles (Cont. ) Perfect alignment is seldom achieved © Goodheart-Willcox Co. , Inc. 43 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Angles (Cont. ) Drive shaft assembly angle (also called operating angle or U-joint angle) © Goodheart-Willcox Co. , Inc. 44 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Angles (Cont. ) On front-engine, rear-wheel drive vehicles, drive shaft assembly angle exists between centerlines of: Transmission output shaft and drive shaft Drive shaft and drive pinion gear shaft © Goodheart-Willcox Co. , Inc. 45 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Angles (Cont. ) Angles are measured at front and rear U -joints Manufacturer’s specification is usually about 1° or 2° If angle is greater than specified: Speed fluctuations of shaft tube increase Shaft may have objectionable vibration Joint can break © Goodheart-Willcox Co. , Inc. 46 Permission granted to reproduce for educational use only.

Drive Shaft Assembly Angles (Cont. ) Angles are affected by: Added weight to vehicle Road surface condition Vehicle acceleration or deceleration Suspension system wear or alterations Original angles must be kept as close as possible to specifications © Goodheart-Willcox Co. , Inc. 47 Permission granted to reproduce for educational use only.

Review Questions To compensate for rear axle movement, the driveshaft ___ and ___ must change. Answer: angle, length © Goodheart-Willcox Co. , Inc. 48 Permission granted to reproduce for educational use only.

Review Questions The ___ slides on the transmission output shaft whenever the rear assembly moves. Answer: slip yoke © Goodheart-Willcox Co. , Inc. 49 Permission granted to reproduce for educational use only.

Review Questions True or False? A slip yoke has external splines. Answer: False. A slip yoke has internal splines. © Goodheart-Willcox Co. , Inc. 50 Permission granted to reproduce for educational use only.

Review Questions A swivel connection, or coupling, that allows the drive shaft assembly to transmit power smoothly is called a(n) ___. Answer: universal joint © Goodheart-Willcox Co. , Inc. 51 Permission granted to reproduce for educational use only.

Review Questions From the slip yoke, power flows into the ___ and then into the drive shaft. Answer: front universal joint © Goodheart-Willcox Co. , Inc. 52 Permission granted to reproduce for educational use only.

Review Questions A double Cardan U-joint is composed of two cross-and-roller U-joints connected by a(n) ___. Answer: center yoke © Goodheart-Willcox Co. , Inc. 53 Permission granted to reproduce for educational use only.

Review Questions A. B. C. D. A cross-and-roller U-joint is sometimes called a ___. Cardan U-joint conventional U-joint double Cardan U-joint Both A and B. Answer: D. Both A and B. © Goodheart-Willcox Co. , Inc. 54 Permission granted to reproduce for educational use only.

Review Questions True or False? The Hotchkiss drive is the most common type of drive shaft assembly. Answer: True © Goodheart-Willcox Co. , Inc. 55 Permission granted to reproduce for educational use only.

Review Questions In a two-piece drive shaft, the ___ keeps the drive shafts aligned. Answer: center support bearing © Goodheart-Willcox Co. , Inc. 56 Permission granted to reproduce for educational use only.

Review Questions Driveshaft assembly angles are measured at the front and rear ___. Answer: U-joints © Goodheart-Willcox Co. , Inc. 57 Permission granted to reproduce for educational use only.