HYDRAULIC SYSTEMS and APPLY DEVICES n Chapter 5 n Page 146 n Reaction Members CBC AUTOMOTIVE RK

REACTION MEMBERS n Reaction members are those parts of a planetary gear set that are held in order to produce output motion. n Multiple-disc clutches n Friction bands n One-way clutches CBC AUTOMOTIVE RK Page 146

BRAKE BANDS n A band is an externally contracting brake assembly that is positioned around the outside of a drum. n A band is a holding device. n Bands are never used to drive a member of the gear set. n Two types of bands –Single-wrap –Double-wrap CBC AUTOMOTIVE RK Page 146

BRAKE BAND TYPES CBC AUTOMOTIVE RK Page 146

SERVOSSERVOS n A band is applied hydraulically by a servo unit. n The band squeezes a drum attached to a gear set member. n A servo can be released by exhausting apply oil. n Or release oil can be applied to the opposite side of the servo piston. CBC AUTOMOTIVE RK Page 147

SERVOSSERVOSSERVOSSERVOS SERVOSSERVOSSERVOSSERVOS CBC AUTOMOTIVE RK Page 149

MULTIPLE-DISC CLUTCH CBC AUTOMOTIVE RK Page 150 n A clutch can hold or drive a planet member. n Clutches have more surface area than bands. n Friction and Steel plates alternate in a drum. n Hydraulic pressure applies clutch piston. n A clutch must have a return spring, retainer. n Rotating clutches must have a check ball.

MULTIPLE-DISC CLUTCH CBC AUTOMOTIVE RK Page 152

ONE-WAY CLUTCHES n One-way or Overrunning clutches are holding devices. n One-way clutches are mechanical devices. n One-way clutches operate at all times, can not be released. n There are two types –Roller clutch –Sprag CBC AUTOMOTIVE RK Page 154

ONE-WAY CLUTCHES CBC AUTOMOTIVE RK Page 155 Roller type

SPRAGSPRAG Page 155 Sprag type one way clutches are usually replaced during overhaul.

SHIFT FEEL n Shift “feel” is controlled by the apply speed of the band or clutch and the timing of the release. n Most clutch packs contain wave springs. n Restricting orifices. n Accumulator pistons. CBC AUTOMOTIVE RK Page 156

ACCUMULATORSACCUMULATORS n Accumulators slow down the apply of other hydraulic devices. n Accumulators contain a piston and spring. n Accumulators do not apply bands. n Accumulators act like shock absorbers. CBC AUTOMOTIVE RK Page 156

ACCUMULATORSACCUMULATORS CBC AUTOMOTIVE RK Page 147