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Massey Ferguson 8737, 8730 Dyna VT transmission PTO - Installing the set of discs on the disc carrier

MF 8400-8700 Series Tractors Repair Operations

MF 8737, 8730 PTO clutch

Massey Ferguson 8737, 8730 Rear PTO drive

Start with an external blade. Next alternate with an internal blade (11). Each internal blade (11) should be fitted in respect to the narrow slot (pos. 2) while the wide slot (pos. 3) should be positioned either side alternately.

Total number of discs: 7 external discs (12) and 6 internal discs (11).

Fit the disc carrier (6) together with the set of Belleville washers (9). Fit the compression tool. Compress the MF 8737, 8730 clutch. Fit the locking half-rings (30).

If the locking half-rings are chamfered on just one side, the chamfered side must face the disc carrier (6). If the disc carrier (6) does not fit into place, fit it without the set of discs (10) and mark the teeth.

Push the set of discs home, ensuring it is correctly centred. Measure the distance (uncoupling clearance) using laminated shims. Specified values: 1.75 to 3.50 mm.

If the minimum distance of 1.75 mm is not obtained, the discs are wrapped. Fit a new set of discs (10). Smear the thread of the nozzle (29) with plastic binder.

Tighten the nozzle (29) to a torque of:25 Nm. If necessary, fit the bearing (28) to its stop with its closed part facing upwards into the interior of the clutch cover (3). Fit the bearing (2) up against the clutch cover (3).

Adjust the position of the external discs (12) and fit the clutch cover (3) to its stop. Fit compensating shims (1) on the bearing (2). Measure and note the distance between the mating faces. For example: 178.6 mm.

The distance between the flange face and the mating face of the journal is written in white on the top part of the rear axle housing. Example: 178.71.

The distance between the journal of the bearing (2) and the flange face of the housing cover should be less than 0.1 to 0.2 mm, as the written value indicates. This means that the journal clearance must be 0.1 to 0.2 mm.

If not, correct it with compensating shims (1). The distance between the flange face and the mating face of the journal of the lower shaft is written in white on the lower part of the rear axle housing. Example: 148.75.

This value is not necessary in case of repair, because a dial gauge must be used to measure the bearing clearance. Check the bearing clearance of the lower shaft (120).

Fit the compensating shims (1) in the upper bore. Smear 4 new O’rings with miscible grease and fit them at the position of the oil pressure pipes.

Clean the housing mating face. Check the 2 locating pins are fitted correctly. Smear the mating face with sealing product. Carefully raise the housing cover and fit it on the rear axle housing. Tighten the M18 screws and nuts to a torque of: 400 Nm.

If necessary: Smear the outside of a new shaft sealing ring (126) with a thin layer of sealing product (ref. X 903.051.711), and insert it until it comes into light contact with the cover (128), the seal lips turned towards the oil chamber. Depth approximately 5 mm. Fill the lip seals 2/3 full with miscible grease.

Fit the corresponding compensating shims (124). Smear new O’rings (127) with miscible grease and fit them in the groove of the cover (128).

Smear the thread of the screws (129) with plastic binder (ref. X 903.050.084) and tighten. Rotate the shaft (120) 10 times. Fit a dial gauge. Push in the shaft (120) once and note the clearance value J2.

Rotate the shaft (120) 10 times. Fit a dial gauge. Pull once on the shaft (120) and note the clearance value J1.
Total clearance J = J1+ J2. 0.02 mm < J < 0.07 mm. If not, correct it with compensating shims (124). PTO end-fitting with 6 x 1’ 3/8" splines.

Also compatible:

PTO end-fitting with 21 x 1’ 3/8" splines
PTO end-fitting with 6 x 1’ 3/4" splines
PTO end-fitting with 20 x 1’ 3/4" splines

The PTO end-fitting has 4 drive holes for the PTO sensor. Fit the end-fitting (137). Fit the spacer (132). Lock the end-fitting (137 with a screw M16 (for easier assembly).