Transmissions 5, 7, 8

CV joints have a variety

-By position (inboard or outboard) -By function (fixed or plunging) -By design (ball-type or tripod)

CV joints location

-nearest the transaxle is INNER or inboard joint -nearest to the wheel is the OUTER or outboard joint

CV joints are held onto the axle shafts by THREE methods

-nonpositive -positive -single retention

Two speed transfer cases are controlled by a shift lever that typically has four positions:

2WD -High: engages only the rear axle and is used for all dry-road driving 4WD-High: engages both axles and is used at any speed on slippery surfaces Neutral: disengages both axles 4WD-Low: engages BOTH axles and lowers the ratios of the entire driveline.

Cross-groove CV joint uses

6 balls in a cage and inner and outer races -grooves in the races are cut on an angle rather than straight -is much flatter design

Plunging tripod joint

Has longer grooves in its hub than a fixed joint = allowing the spider to move in and out within the housing

A transfer case

Have a gear or chain drive to transmit power to one or both of the drive axles -There are two speeds: a high range for normal driving at a low range for especially difficult terrain

4WD system

Have a separate transfer case that allows for the transfer of engine power to two wheels or four wheels.

Equal-length shafts

Help reduce torque steer. The longer side is made into TWO pieces. -One piece comes out of the transaxle and is supported by a bearing assembly attached to engine - The other piece is made to the same length as shorter side axle.

Bellows-type Neoprene boot

Is sealed tightly against the shaft or housing by a retaining clamp or strap

Double offset joint

Longer grooves in the inner race of a Rzeppa joints allow the bearing cage to slide in and out

FWD (difference from 4wd)

Modified by adding a transfer case, a rear drive shaft, and rear axle with a differential.

Front wheel hubs (4WD)

Must be locked or unlocked by driver. Rear wheel hubs are ALWAYS ENGAGED

4WD systems

On demand 4 Wheel Dr. systems power a second axle only after the first begins to slip

A FWD has two short drive shafts...

On each side of the engine, drive the wheels and adjust steering and suspension changes

Outer joints

Typically wear at a higher rate than inner joints because of the increased range of operating angles

What type of cars use CV joints other than FWD?

Used on front axles of AWD and 4WD. Can be used on IRS rear drive axles and RWD buses and cars that have engine mounted in rear

PART-TIME 4WD

Used only off road or slippery surfaces -when engaged, the system locks the front and rear axles together

Constant velocity joints or CV joints

Used to transfer a uniform torque and a constant speed when operating through a wide range of angles.

The most commonly used type of CV joint

Rzeppa

Fixed tripod CV joints uses

A central hub or tripod that has 3 trunnions fitted with spherical rollers on needle bearings -spherical OR balls ride in the grooves of an outer housing that is attached to the front wheels

4WD - part-time 4WD

Allow driver to go in and out of four-wheel-drive.

Bellows-type neoprene boots

Are installed over each CV joint to retain lubricant and to keep OUT the moisture and dirt

Drive axles -

Are supported in steering knuckle by wheel bearings. -These bearings allow the axle to rotate evenly and smoothly and keep the axle in the center of the steering knuckle's hub.

Drive chains

Are used to link the input and output shaft and a transfer case and serve as a link that does not influence gear ratios.

Small damper weight

Attached to one half shaft to dampen harmonic vibrations in the driveline AND stabilize the shaft as it spins

A Rzeppa CV joints

Can be modified to become a plunging joint by making the grooves in the INNER race longer

Half shaft

Complete drive axle (inner and outer CV joints)

Front wheels

During a turns-Travel a greater distance bc the move through a wider ARC than rear wheels

4wd

Engine power can flow to all 4 wheels and that increases the vehicles traction.

CV joints are...

FIXED - they do not plunge in and out to compensate for changes in length PLUNGING - one that is capable of in-and -out movement

Transfer cases news spur or helical gears it to provide for the speed ranges for engagement and disengagement of four-wheel-drive

HOW: The front axle is engaged by shifting a sliding or clutch and gear into engagement with the driven gear on the driveshaft for the front wheels inside the transfer case. the sliding years and clutches are driven through splines on the shafts.

Rzeppa CV joints

Has its inner race attached to the axle -The # of grooves = the # of ball bearings used by the joint -minimum of 3 to a max of 6 ball bearings -the bearing cage keeps the joints ball bearings in place as they ride in the groove of the inner race.

Torque Steer

The car tends to steer or pull in one direction as engine power is applied to drive wheels

If Half shafts are not equal in length ...?

The longer one is made THICKER than the shorter one. OR one axle may be solid and the other is tubular. BOTH would allow axles to twist the same amount when under engine power.

The planetary gear set

There are low and high range speeds -Speed reduction and provides the low range —

A simple planetary gear set

There are three gears: -The sun gear is found in the center which all other gears in the set revolve. This year is mashed with three or four planetary pinion gears held together by planetary Pinyan carrier or planetary carrier. - The ring gear is on the outside of the planetary pinons it has teeth around it inside the circumference that mesh with the teeth of the planetary pinions. * each planetary pinion gear is mounted to the planetary carrier by a pin or shaft

The purpose of a transfer case

To transfer torque from the output of the transmission to the vehicles front and rear axles

Shift on the fly system

Using magnetic plug in the transfer case to bring the front driveshaft differential and drive axle to the same speed as the transmission. When the speeds are synchronized an electric motor in the transfer case completes the shift.

4WD systems

use Computer controls to enhance operation, adjust torque split depending on traction of the wheels.