DISC-THRUST 8E8299 - Caterpillar

Nine transmission clutches are located in the transmission.
Illustration 1 g01325158
Five Transmission Shafts (1) Planetary carrier (2) Gear (3) Clutch pack (4) Gear (5) Planetary carrierNote: Gear (4) meshes only with gear (2). The configuration of the five transmission shafts in Illustration 1 is only for illustrative purposes.There are seven similar clutch packs (3) that are located on four shafts. There are two identical planetary clutch packs that fit to planetary carriers (1) and (5). The planetary clutch packs are fastened to the front and rear transmission cases. See Illustrations 2 and 3.
Illustration 2 g01325161
Front Transmission Case (6) Planetary clutch pack (7) Front transmission caseOne planetary clutch pack (6) is located in front transmission case (7). This planetary clutch pack fits to planetary carrier (1). See Illustration 1.
Illustration 3 g01325168
Rear Transmission Case (8) Planetary clutch pack (9) Rear transmission caseOne planetary clutch pack (8) is located in rear transmission case (9). This planetary clutch pack fits to planetary carrier (5). See Illustration 1.Each clutch pack and planetary clutch pack is controlled by a corresponding modulating valve (transmission). There are nine modulating valves for the nine clutch assemblies.ReferenceSee Systems Operation/Testing and Adjusting, "Transmission Power Flow" for additional information.
Illustration 4 g01325173
Transmission Shafts (8) Input shaft (9) Intermediate shaft (10) Output shaft (11) Transfer gear shaftThe following shafts contain clutch packs and planetary clutch packs that control the FORWARD speeds:
Input shaft (8)
Intermediate shaft (9)
Output shaft (10)
Illustration 5 g01325179
Transmission Shafts (2) Gear (4) Gear (8) Input shaft (9) Intermediate shaft (10) Output shaft (11) Transfer gear shaft (12) Reverse shaftNote: Gear (4) meshes only with gear (2). The configuration of the five transmission shafts in Illustration 5 is only for illustrative purposes.The following shafts contain clutch packs and planetary clutch packs that control the REVERSE speeds:
Input shaft (8)
Intermediate shaft (9)
Output shaft (10)
Reverse shaft (12) ReferenceSee Systems Operation/Testing and Adjusting, "Transmission Power Flow" for additional information.Oil Flow and Rotational Power Flow
Regular Clutch Pack
Illustration 6 g01335097
(1) Clutch pack (13) Gear (14) Spring (15) Clutch lubrication passage (16) Friction discs (17) Clutch plates (18) Balance piston (19) Piston (20) Oil passage (21) Oil passage (22) CylinderOil flows from the modulating valve through oil passage (20) in the transmission shaft. Oil fills the chamber behind piston (19) .Piston (19) is used for the following functions:
The piston will compress clutch plates (17) against friction discs (16) .
The piston will control lube flow to the friction discs and the clutch plates.Note: Illustration 6 shows the clutch in the disengaged position.Clutch Engagement
As pressure builds up behind the piston, the piston will start to move toward the friction discs and clutch plates. This will eventually overcome the spring and the lubrication oil pressure in front of the piston. At maximum pressure, the piston will completely compress the friction discs and clutch plates.The clutch plates are engaged to cylinder (22) by the use of spline teeth. Because the cylinder is rotating with the transmission shaft, the clutch plates will cause the friction discs to rotate.Because the friction discs are engaged to gear (13) by the use of spline