Usage:
NOTE: In the discussion that follows, the input side of the transmission is the front and the output side is the rear.
Figure 8-1 : Forward Clutch - Cross section.
Disassembly of Forward or Reverse Clutch (Figures 8-1).
NOTE: Since both clutches are practically identical in construction only the procedure for the forward clutch is shown. This procedure can be used to disassemble the reverse clutch.
1. Support the forward clutch assembly on the workbench with the input end up.
2. Remove the piston ring remaining on the rear end of the input shaft (see figure 8-2).
Figure 8-2 : Removal of piston ring.
3. Use a guilloting-type bearing puller and remove the rear tapered outer bearing (see figure 8-3).
| NOTICE |
|---|
Care must be exercised during removal of the rear tapered roller bearing (figure 8-17, 25) from the forward shaft (figure 8-17, 7). Bearing puller must be installed in a manner, which will assure that removal pressure is applied behind the bearing inner cone without binding on the OD of the rear thrust race (figure 8-17, 24). Loose adjustement of the bearing puller will result in application of pressure on the bearing cage, which will destroy the bearing. Excessively tight adjustment of the bearing puller will exert pressure on the OD of the rear thrust race, which will either damage the thrust race or cause the thrust race to bind on the shaft, which could damage the shaft. |
Figure 8-3 : Pulling rear tapered roller bearing.
4. Remove the forward pinion (see figure 8-4) with two rear thrust races and the thrust needle bearing (see figure 8-5).
5. Remove the two front thrust races and needle bearing (see figure 8-6).
6. Remove the clutch backplate (see figure 8-7).
Figure 8-4 : Removing or installing pinion on clutch shaft.
Figure 8-5 : Rear thrust needle bearing and thrust races removed.
Figure 8-6 : Removal or installation of front thrust needle bearing and thrust races.
Figure 8-7 : Removal or installation of clutch backplate and snap ring.
7. Remove the clutch plates (see figure 8-8).
8. Place special tool TD 300411 over the clutch release spring (see figure 8-9). Use a hydraulic press to press tool downward and compress the spring. Remove the snap ring from the groove in the shaft.
9. Remove tool TD-300411 and remove the spring retaining snap ring, spring retainer and spring from the shaft (see figure 8-10).
10. Remove the clutch piston by knocking the end of the clutch shaft on a piece of wood (see figure 8-11).
11. Remove the piston ring from the outer periphery of the clutch piston and the O-ring from the inner diameter (see figure 8-12).
Figure 8-8 : Clutch plates removed.
| NOTICE |
|---|
Do not remove front tapered roller bearings (figure 8-17, 5) from forward (7) or reverse shaft unless replacement of the parts is necessary. Close tolerances between inner bearing cone and rear face of transfer gear prohibits installation of bearing puller behind inner cone. |
Figure 8-9 : Compressing clutch release spring.
Figure 8-10 : Removal of clutch release spring, retainer and snap ring.
Figure 8-11 : Removing clutch piston.
Figure 8-12 : Clutch piston, piston ring and O-ring removed.
If the bearing must be removed, proceed as follows :
a. Split the bearing cage of front taper roller bearings (figure 8-17, 5) and remove the rollers.
b. Install a cheese-cutter type bearing puller onto the bearing cone, gripping against the shoulder on the cone.
c. Heat bearing cone by flash heating and pull it from the shaft.
| NOTICE |
|---|
Prolonged or excessive heating must be avoided to prevent annealing the clutch shafts. |
NOTE: Do not remove the transfer gears (clutch housings) from the shafts. They are supplied as an assembly and are not serviceable separately.
Cleaning and Inspection.
See section 7 for cleaning and inpection instructions.
Assembly of Forward or Reverse Clutch.
1. If the front bearing cone was removed from the shaft for replacement heat the new bearing cone to a temperature of 135° C. (275° F.) and install it on to the shaft.
2. Install a new piston ring and O ring on to the clutch piston.
3. Install the clutch piston into the clutch housing using special tool TD 300433 (see figure 8-13).
Figure 8-13 : Installation of clutch piston with special tool TD 300433
4. Install the clutch release spring and spring retainer and place the retaining snap ring on to the shaft as close as possible to the spring retainer.
5. Using tool TD-300413 and a hydraulic press, compress the spring and push the snap ring down until it locates itself in the groove provided in the shaft (see figure 8-14).
6. Install the clutch plates as follows:
a) Immerse all sintered clutch plates in appropriate oil for a period of at least one hour prior to assembly.
b) Starting with a sintered plate install the ten (10) sintered clutch plates and nine (9) steel clutch plates thereby finishing with a sintered plate.
Figure 8-14 : Installing spring retainin snap ring using special tool TD 300413.
7. Install the clutch backplate and retaining snap ring (see figure 8-7).
8. Install the front thrust race with the recessed bore over the clutch spring retaining snap ring. Install the needle bearing and the second thrust race (see figure 8-6).
9. Align the internal teeth of the steel clutch plates as closely as possible, lightly oil the shaft and install the forward pinion on to the clutch shaft. Rotate the pinion backwards and forwards to assist the engagement of the splines with the teeth of the steel plates. Ensure that the pinion is completely engaged through all nine (9) steel plates.
10. Install the front thrust race, needle bearing and rear thrust race on to the shaft.
11. Heat the rear roller bearing cone to a temperature of 135° C. (275° F) and install it on to the shaft (see figure 8-15).
Figure 8-15 : Installation of rear bearing cone.
Figure 8-16 : Reverse Clutch - Cross section.
12. Install new piston rings into the grooves at the rear end of the clutch shaft (see figure 8-2).
Disassembly of Selector Valve.
NOTE: Illustration numbers refer to figure 6-25.
1. Remove the four capscrews (figure 6-25, 48) and remove the cover (47), gaskets (44, 46) and orifice plate (45). See figure 8-19.
NOTE: The steel ball (43) is under pressure from the spring (42). Care must be taken when removing the orifice plate so that the ball will not be lost.
Forward Clutch - Exploded View. Figure 8-17:
Reverse Clutch - Exploded View. Figure 8-18:
Figure 8-19 : Removal of orifice plate and cover.
2. Remove the steel ball and spring from the manifold.
3. Remove the rate-of-rise piston (41), with its shims (40) and inner and outer springs (18, 19) from the manifold.
4. Remove the two capscrews (10) securing the detent plate (14).
5. Remove the detent plate with the valve stem (16) and pressure regulating piston (17) from the manifold (see figure 8-20).
6. Remove the screw (11) from the shift lever (13) and remove the lever from the valve stem.
7. Remove the O ring (15) from the valve stem.
Cleaning and Inspection.
See section 7 for cleaning and inspection procedures.
Figure 8-20 : Removal of the valve stem.
Assembly of Selector Valve Assy.
NOTE: Illustration numbers refer to figure 6-25.
1. Install the O-ring (15) on to the valve stem (16).
2. Install the regulator piston (17) into the valve stem and install the valve stem into the manifold. Secure the valve stem with the detent plate (14) and two capscrews (10). Torque the capscrews 15 lbs. ft.
3. With the valve stem in the neutral position, secure the shift lever (13) to the valve stem using the screw (11) and nut (12).
4. Install the rate of rise piston (41) with its shims (40) and inner and outer springs (18, 19) into the manifold.
5. Install the spring (42) and steel ball (43) into the manifold.
6. Install gasket (44), orifice plate (45), gasket (46) and cover (47) and secure with four capscrews (48). Torque the screws to 22 lbs. ft.
Disassembly of Trolling Valve. - (where applicable)
NOTE: Illustration numbers refer to figure 8-21.
1. Remove the three socket screws (13) securing the trolling valve assy to the manifold assy.
NOTE: The trolling valve must be out of detent position to avoid fly-up of the trolling valve assy due to spring compression.
2. Remove trolling valve ass'y and gasket (15) from the manifold.
3. Remove the orifice seat (14), plunger (3), springs (12, 20) and washer (19) from the trolling valve body (9).
4. Remove the detent plug (18), spring (17) and ball (16).
5. Turn the trolling stem (7) to its fully out position and tap out the two dowel pins (1, 2) through the hole provided in the stem.
6. Pull the trolling valve stem from the valve body and remove the O ring (10).
7. Remove the screw and nut (4, 5) and remove the operating lever (6).
NOTE: Do not remove roll pin (11) from trolling stem unless replacement of parts is necessary.
8. Remove oil seal (8) from valve body.
Cleaning and Inspection.
See section 7 for cleaning and inspection procedures.
Assembly of Trolling Valve.
NOTE: Illustration numbers refer to figure 8-21.
1. Install a new O ring (10) on to the trolling stem (7).
2. Apply general purpose grease to the trolling stem, and install the stem into the valve body (9).
3. Using a piece of tube slightly larger than the trolling stem press a new oil seal (8) into the valve body.
4. Line up the cam slot in the stem with the pin holes in the valve body and install the two pins (1, 2).
NOTE: Do not push the pins into the valve body too far as this will prevent the stem from turning freely.
5. Locate the stem in the fully out position and install the washer (19), springs (12, 20) and plunger (3).
Figure 8-21 : Trolling Valve Assembly.
6. Install the ball (16), spring (17) and detent plug (18_.
7. Install the orifice seat (14).
8. Ensure that the mating surfaces of the valve body and manifold are clean and install a new gasket (15).
9. Install the trolling valve ass'y to the manifold and secure it with the screws (15). Torque the screws 22 lbs. ft.
10. Install the operating lever (6) in its correct position on the stem and secure it with the screw and nut (4, 5).
NOTE: After reassembly check the operating linkage to ensure that the trolling stem returns to the detent position when the control lever is in the no trolling position.
Failure to do this could result in severe damage to the marine transmission due to low clutch pressure. Twin Disc will not be responsible for damage caused by faulty control linkage or bad linkage adjustment.