7/17/2019 At1

1/25

2012 Delmar, Cengage Learning

Front-Wheel-Drive (Transaxle

and CV Joint F!ndamentals

Cha"ter ##

7/17/2019 At1

2/25

2012 Delmar, Cengage Learning

$%&e'tives

Des'ri%e di))eren'es %et*een )ront- and rear-

*heel drivetrains

Tell the names o) "arts o) a transaxle

Tra'e the "o*er )lo* thro!gh )o!r- and )ive-s"eed transaxles

7/17/2019 At1

3/25

2012 Delmar, Cengage Learning

+ntrod!'tion

ost a!tomo%iles toda have )ront-*heel drive

. FWD 'ar has transaxle

. Drive axles extend to )ront *heels o!t o) ea'h

side o) transaxle. /a'h end o) the drive axle is a CV &oint

. Transaxle 'an %e either man!al or a!tomati'

7/17/2019 At1

4/25

2012 Delmar, Cengage Learning

7/17/2019 At1

5/25

2012 Delmar, Cengage Learning

Front-Wheel Drive

dvantages

. ore e))i'ient drivetrain

. etter )!el e'onom

. Com%ined *ith a'herson str!ts3 less!ns"r!ng *eight )or %etter handling

Transmission h!m" is eliminated

)e* FWD engines have %een mo!nted

longit!dinall

. ost transaxles mo!nted side*as

7/17/2019 At1

6/25

2012 Delmar, Cengage Learning

7/17/2019 At1

7/25 2012 Delmar, Cengage Learning

7/17/2019 At1

8/25 2012 Delmar, Cengage Learning

an!al Transaxle

an!al transaxles and transmissions

. 4se same 5ind o) 'l!t'h

Three "arallel "aths )or "o*er )lo*

. +n"!t sha)t lo'ated a%ove intermediate sha)t +n"!t sha)t gears dire'tl drive o!t"!t sha)t gears

. Di))erential assem%l

6ear sha)ts. 7!""orted % larger %all, roller, or ta"ered roller

%earings

. /nd "la is 'ontrolled % thr!st *ashers

7/17/2019 At1

9/25 2012 Delmar, Cengage Learning

7hi)t Lin5age

Transverse transaxles

. 7hi)ted % 'a%les or shi)t lin5age

T*o shi)t 'a%les or rods

. $ne moves a sele'tor on transaxle

. $ther moves shi)t )or5 %a'5 and )orth

dvantage

. /ngine sha5e is not transmitted %a'5 to driver8shand on shi)t lever

7/17/2019 At1

10/25 2012 Delmar, Cengage Learning

7/17/2019 At1

11/25 2012 Delmar, Cengage Learning

7/17/2019 At1

12/25 2012 Delmar, Cengage Learning

Transaxle Di))erential

llo*s *heels to t!rn at di))erent s"eeds *hen

ro!nding 'orners

. 7ame as rear-*heel-drive di))erential

$rdinar heli'al gearset. 4sed instead o) %evel gears

. o*er )rom di))erential side gears is transmitted

to )ront drive axles thro!gh axle sha)ts

7/17/2019 At1

13/25 2012 Delmar, Cengage Learning

Transaxle o*er Flo*

Five-s"eed "o*er )lo*

. Fixed gears )or )irst, se'ond, and reverse on

in"!t sha)t

. Fixed gears )or third, )o!rth, )i)th on intermediatesha)t

. o*er )lo* leaves transmission intermediate

sha)t

Contin!es thro!gh drive "inion to axles

. /ngine is mo!nted side*as

xles r!n "arallel to in"!t sha)t

7/17/2019 At1

14/25 2012 Delmar, Cengage Learning

7/17/2019 At1

15/25 2012 Delmar, Cengage Learning

7/17/2019 At1

16/25

2012 Delmar, Cengage Learning

!tomati' Transaxle

Com%ination o) a!tomati' transmission and

di))erential

. 7ame "arts and o"eration a""l

Transverse engine. o*er )lo* is thro!gh gears or s"ro'5et and

'hain

Chain drive

.llo*s transaxle to %e mo!nted slightl %elo*

and to the side o) the engine

7/17/2019 At1

17/25

2012 Delmar, Cengage Learning

Front Drive xles

Di))eren'e %et*een rear-*heel drive and )ront-

*heel drive axles

. Front-*heel drive axles have CV &oints at ends

xles driven at shar"er angles llo* steering )ront *heels d!ring "o*er

transmission

. 4niversal &oint 'hanges o!t"!t s"eed t*i'e in

ever revol!tion *hen r!n at an angle. 9ear-*heel drive vehi'le drive sha)t t!rns ver

)ast

ositioned %e)ore gear red!'tion o) di))erential

7/17/2019 At1

18/25

2012 Delmar, Cengage Learning

xle 7ha)t arts

Drive axle is 'alled hal) sha)t or axle sha)t

7t!% sha)t (st!% axle

. 7hort sha)t at o!tside end

. 7"lined to )ront h!% so it 'an drive )ront *heels

CV &oint 'lassi)i'ations

. +n%oard and o!t%oard

. Fixed and "l!nge. all and tri"od

7/17/2019 At1

19/25

2012 Delmar, Cengage Learning

CV Joint Constr!'tion

ost 'ommon &oint 'om%ination

. 9:e""a &oint )or o!tside )ixed &oint and a tri"od

)or inside "l!nge &oint

Fixed &oints. 9:e""a &oint3 %all-and-so'5et t"e

T"es o) "l!nge &oints

. Tri"od t!li". Do!%le o))set "l!nge &oint

. Cross groove "l!nge &oint

7/17/2019 At1

20/25

2012 Delmar, Cengage Learning

7/17/2019 At1

21/25

2012 Delmar, Cengage Learning

7/17/2019 At1

22/25

2012 Delmar, Cengage Learning

xle 7ha)ts

Chara'teristi's

. a %e solid or hollo*

. a have dam"er *eights to a%sor% vi%ration

. T!rn m!'h slo*er than rear-*heel drive sha)t alan'e not as im"ortant

. When di))erent lengths3 long one t*ists and lags

%e)ore "!ts its tor;!e to the *heel

Tor;!e steer is "revented % longer axle sha)t o)

larger diameter t!%ing

7/17/2019 At1

23/25

2012 Delmar, Cengage Learning

7/17/2019 At1

24/25

2012 Delmar, Cengage Learning

7/17/2019 At1

25/25

2012 D l C L i

CV Joint oots

oots at ea'h end o) axle 'ontain grease

. rote't &oint )rom the elements

CV &oint %oot

.tta'hed to axle and st!% sha)ts *ith "lasti' orsteel %ands or stra"s

. ade o) nat!ral r!%%er, neo"rene, sili'one, or

!rethane