Engine Flywheel and damper


The damper (3) installed on the flywheel is secured by splines onto main shaft (6). It provides a
flexible connection between the engine and gearbox and damps any vibrations caused by the transmission. It is installed on tractors fitted with the Powershift AG150 (Fig1) Powershift Gearbox AG250 (Fig2) and Heavy gearboxes (fig3)

AG 150 - AG250 versions (Fig.1-2)
- Bearing (1) fit in the flywheel is sealed on both faces.
The seal is to give better reliability. The bearing supports main shaft (6) and does not itself rotate. Its position in the flywheel remains variable depending on the type of gearbox and the engine type. It may be bearing on a shoulder of the flywheel, or on a circlip.
- Spring (5) maintains the main shaft in position.
- The damper, the main shaft and the bearing form an assembly rotating at the speed of the flywheel.

Heavy Duty version (Fig.3)
- The principle of installation and operation remain similar.
Note, however, that:
- the spring is excluded, since the main shaft installation differs from that shown for the previous version;
-the bearing has one position only, and is in contact with the shoulder of the flywheel.
The part number of damper (3) differs according to the version.

Split the tractor between the engine and the gearbox.
Remove screws (4).
Remove damper (3).
Check the parts and replace any that are faulty.

If the operation consists in changing the damper, also replace the bearing.

Lightly coat the splines of the damper hub with GN grease + Molycote. Refit and centre the damper, the offset on the hub pointing towards the gearbox (Figs. 1 - 2).
Lightly coat the threads of screws (4) with Loctite 270 and torque to following values:
- Powershift gearbox (AG150-AG250):
M10 screws: 68 - 92 Nm.
- Heavy gearbox:
M12 screws: 102 - 138 Nm
Reassemble the tractor between the engine and gearbox.

Powershift gearbox AG150



 Fig1

Parts list
(1) Bearing
(2) Starter ring gear
(3) Damper
(4) Screw
(5) Spring
(6) Main shaft
(7) Gearbox
A - 86 mm
B - 107,95 mm

Powershift gearbox AG250



Fig2 

Parts list
(1) Bearing
(2) Starter ring gear
(3) Damper
(4) Screw
(5) Spring
(6) Main shaft
(7) Gearbox
(8) Circlip
A - 86 mm
B - 94 mm

Heavy gearbox 




Fig3

Parts list
(1) Bearing
(2) Starter ring gear
(3) Damper
(4) Screw
(5) Spring
(6) Main shaft
(7) Gearbox
A - 86 mm
B - 107,95 mm


Split the tractor between the engine and the gearbox.
Lock the flywheel using a suitable fixture.
Remove the damper.
Remove the flywheel.
Drive out bearing (1) (Figs. 1 - 2)

- On certain types of installation (Figs. 1 - 2) , extraction of the bearing is possible without removing the flywheel, using a slide hammer.
- If installing a type A flywheel and a Powershift gearbox AG250, replace circlips (8) and the bearing (Fig. 1)

Refitting

Check the parts, replacing any that are defective.
Screw two guide studs opposite one another into the holes used for attaching the flywheel on the crankshaft.
Refit the flywheel.

Depending on the type of fixture, fit bearing (1) before or after refitting the flywheel, using
a suitable mandrel (dia. 62 mm, corresponding to the hole in the external cage of the bearing).

Remove the guide studs. Torque the screws to 140 Nm (Perkins engine). For the screw torquing
values on Valmet flywheels, refer to the engine repair manual.
Refit the damper.
Reassemble the tractor between the engine and gearbox.

Replacing the starter ring gear

Disassembly

Split the tractor between the engine and gearbox.
Remove the damper.
Remove the flywheel.
Using a suitable-strength drill bit, drill a hole (Ø 5) to the same depth as the width of ring gear (2) to avoid touching the flywheel. Use a suitable cold chisel to split the ring gear (Fig. 3).

When breaking the ring gear, provide some protection to stop splinters of material.

Reassembly

Heat a new ring gear to 245° C in a furnace only.
Install ring gear (2) on the flywheel, with the teeth opening pointing towards the starter, and fit rapidly into abutment. Allow to cool slowly.
Refit the flywheel and the damper.
Reassemble the tractor between the engine and gearbox.