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

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

Permission granted to reproduce for educational use only. 3 © Goodheart-Willcox Co., Inc. 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.

Permission granted to reproduce for educational use only. 4 © Goodheart-Willcox Co., Inc. 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.

Permission granted to reproduce for educational use only. 5 © Goodheart-Willcox Co., Inc. 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

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

Permission granted to reproduce for educational use only. 7 © Goodheart-Willcox Co., Inc. 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

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

Permission granted to reproduce for educational use only. 9 © Goodheart-Willcox Co., Inc. 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)

Permission granted to reproduce for educational use only. 10 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 11 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 12 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 13 © Goodheart-Willcox Co., Inc. Drive Shaft Drive shaftDrive 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

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

Permission granted to reproduce for educational use only. 15 © Goodheart-Willcox Co., Inc. 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)

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

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

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

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

Permission granted to reproduce for educational use only. 20 © Goodheart-Willcox Co., Inc. 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)

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

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

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

Permission granted to reproduce for educational use only. 24 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 25 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 26 © Goodheart-Willcox Co., Inc. CV Joints Constant-velocity U-jointsConstant-velocity U-joints (CV 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

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

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

Permission granted to reproduce for educational use only. 29 © Goodheart-Willcox Co., Inc. 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)

Permission granted to reproduce for educational use only. 30 © Goodheart-Willcox Co., Inc. 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 rear- wheel drives with independent rear suspension

Permission granted to reproduce for educational use only. 31 © Goodheart-Willcox Co., Inc. 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

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

Permission granted to reproduce for educational use only. 33 © Goodheart-Willcox Co., Inc. 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

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

Permission granted to reproduce for educational use only. 35 © Goodheart-Willcox Co., Inc. 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)

Permission granted to reproduce for educational use only. 36 © Goodheart-Willcox Co., Inc. Torque-Tube Drive Torque-tube driveTorque-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

Permission granted to reproduce for educational use only. 37 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 38 © Goodheart-Willcox Co., Inc. 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

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

Permission granted to reproduce for educational use only. 40 © Goodheart-Willcox Co., Inc. 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)

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

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

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

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

Permission granted to reproduce for educational use only. 45 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 46 © Goodheart-Willcox Co., Inc. 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

Permission granted to reproduce for educational use only. 47 © Goodheart-Willcox Co., Inc. 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

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

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

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

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

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

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

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

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

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

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

Permission granted to reproduce for educational use only. 58 © Goodheart-Willcox Co., Inc. Glossary Axial centerline Central axis around which rotating parts revolve. Also called rotational axis Ball-and-trunnion U-joint In addition to allowing the drive shaft assembly to bend, this joint also allows fore-and-aft (forward and backward) movement of the propeller shaft. Not used on modern vehicles.

Permission granted to reproduce for educational use only. 59 © Goodheart-Willcox Co., Inc. Glossary Cardan U-joint A center cross (or spider) and four cups (or caps) containing needle bearings. The cups are machined to fit into the drive shaft yokes, the slip yoke, and the differential pinion yoke. The needle bearings allow the yokes to swivel on the cross ends with minimal friction. Also called cross-and- roller U-joint or conventional U-joint

Permission granted to reproduce for educational use only. 60 © Goodheart-Willcox Co., Inc. Glossary Companion flange Two-piece assembly, consisting of two mating flanged sections. One flange holds the rear universal joint, and the other connects to the pinion gear. The arrangement attaches the rear universal joint to the pinion. Also called differential pinion flange Constant-velocity U-joint Flexible joint that provides a constant flow of power through angles between drive and driven shafts. Also called CV joint

Permission granted to reproduce for educational use only. 61 © Goodheart-Willcox Co., Inc. Glossary Conventional U-joint A center cross (or spider) and four cups (or caps) containing needle bearings. The cups are machined to fit into the drive shaft yokes, the slip yoke, and the differential pinion yoke. The needle bearings allow the yokes to swivel on the cross ends with minimal friction. Also called cross-and- roller U-joint or Cardan U-joint

Permission granted to reproduce for educational use only. 62 © Goodheart-Willcox Co., Inc. Glossary Cross-and-roller U-joint A center cross (or spider) and four cups (or caps) containing needle bearings. The cups are machined to fit into the drive shaft yokes, the slip yoke, and the differential pinion yoke. The needle bearings allow the yokes to swivel on the cross ends with minimal friction. Also called Cardan U- joint or conventional U-joint

Permission granted to reproduce for educational use only. 63 © Goodheart-Willcox Co., Inc. Glossary CV joint Flexible joint that provides a constant flow of power through angles between drive and driven shafts. Also called constant-velocity U-joint Differential pinion flange Two-piece assembly, consisting of two mating flanged sections. One flange holds the rear universal joint, and the other connects to the pinion gear. The arrangement attaches the rear universal joint to the pinion. Also called companion flange

Permission granted to reproduce for educational use only. 64 © Goodheart-Willcox Co., Inc. Glossary Differential pinion yoke Connects to the drive pinion gear in the rear axle assembly. The yoke has internal splines that fit external splines on the drive pinion gear shaft. The yoke is held to the shaft by a large locknut. Double Cardan U-joint CV joint constructed with a cross-and-roller U-joint at each end of a special coupling yoke, called a center yoke. A central ball-and-socket connection acts as a centering device.

Permission granted to reproduce for educational use only. 65 © Goodheart-Willcox Co., Inc. Glossary Drive shaft Means of transmitting power from the transmission to the rear axle assembly. Drive shaft assembly angles The angles between the centerlines of the transmission output shaft and drive shaft and between the drive shaft and the drive pinion gear shaft. Also called operating angles or U-joint angles

Permission granted to reproduce for educational use only. 66 © Goodheart-Willcox Co., Inc. Glossary Hotchkiss drive Drive shaft assembly that uses an open shaft with two or more U-joints Operating angles The angles between the centerlines of the transmission output shaft and drive shaft and between the drive shaft and the drive pinion gear shaft. Also called drive shaft assembly angles or U-joint angles

Permission granted to reproduce for educational use only. 67 © Goodheart-Willcox Co., Inc. Glossary Perfect alignment When all centerlines line up exactly, forming one long centerline. Rotational axis Central axis around which rotating parts revolve. Also called axial centerline Rzeppa joint Flexible joint used in front drive axles.

Permission granted to reproduce for educational use only. 68 © Goodheart-Willcox Co., Inc. Glossary Salsbury drive Drive shaft assembly in which coil springs are used to attach the rear axle to the vehicle. Slip yoke Connects through the U-joint to the front of the drive shaft. It slides back and forth within the transmission, allowing the drive shaft length to change with rear axle movement. It may also be mounted at the rear of the front drive shaft in four- wheel drive vehicles.

Permission granted to reproduce for educational use only. 69 © Goodheart-Willcox Co., Inc. Glossary Torque-tube drive Drive shaft assembly with a drive shaft that is solid steel and enclosed in a tube. The tube is solidly connected to the rear axle assembly with bolts. Tripod joint Joint used as the inboard, plunging CV joint on many CV axle assemblies. This type of joint contains a three-pointed cross, or spider, assembly, which is attached to the axle shaft through a splined connection.

Permission granted to reproduce for educational use only. 70 © Goodheart-Willcox Co., Inc. Glossary Two-piece drive shaft A drive shaft that is divided into two sections, with a universal joint between the front and rear sections. U-joint Joint that allows for changes in driveline angles when the rear axle is moving up or down over road surface irregularities. Also called universal joint

Permission granted to reproduce for educational use only. 71 © Goodheart-Willcox Co., Inc. Glossary U-joint angles The angles between the centerlines of the transmission output shaft and drive shaft and between the drive shaft and the drive pinion gear shaft. Also called drive shaft assembly angles or operating angles Universal joint Joint that allows for changes in driveline angles when the rear axle is moving up or down over road surface irregularities. Also called U-joint