GPA30 rear PTO - 1000 rpm output shaft


The GPA30 rear axle PTO housing encloses:
- the driving pinion;
- the driven pinion (18) (1000 rpm);
- the 1000 rpm output shaft (13).


The output shaft is supported:
- at the front by a cylindrical roller bearing (24). This bearing is directly fitted into the rear partition of the centre housing;
- at the rear, by two taper roller bearings (3) (19) and (8) (21).
Taper roller bearing clearance is adjusted using shim(s) (23) placed between the PTO housing and the rear bearing (22). The driven pinion (18) is constantly meshed with the upper shaftline driving pinion. It is also linked to the output shaft (1000 rpm) (13) via the hub (11) and coupler (10), coupled by means of the circlip (27). The castellated washer (4) is integral to the 1000 rpm output shaft (13) via a tab. This washer informs the tractor electronic system of the output speed of the output shaft (13) via a sensor (if fitted) located on the lower right-hand side of the PTO housing.

Lubrication
A central channel with a radial port in the 1000 rpm output shaft (13) provides splash lubrication of:
- the front cylindrical roller bearing (24);
- the rear taper roller bearings (3) (19) and (8) (21).
The oil tightness of the rear bearing is provided by cassette seal (14) and O'ring (15).

Parts list 
(1) Circlip (2) Screw (3) Bearing cone (4) Castellated washer for sensor (if fitted) (5) Flange shaft (6) Screw (8) Bearing cone (9) Protector (10) Coupler (11) Hub (13) 1000 rpm output shaft (14) Cassette seal (15) O’ring (16) Circlip (17) Circlip (18) 1000 rpm driven gear (19) Bearing cup (21) Bearing cup
(22) Rear bearing (23) Shim(s) (24) Cylindrical roller bearing (25) Oil deflector (26) Circlip (27) Circlip (35) Locating pin

Parts list 
(1) Circlip (2) Screw (3) Bearing cone (4) Castellated washer for sensor (if fitted) (8) Bearing cone (10) Coupler (11) Hub (13) 1000 rpm output shaft (14) Cassette seal (15) O’ring (16) Circlip (17) Circlip
(18) 1000 rpm driven gear (19) Bearing cup (21) Bearing cup (22) Rear bearing (23) Shim(s) (24) Cylindrical roller bearing (25) Oil deflector (26) Circlip (27) Circlip (35) Locating pin (36) Cup plugs

Removing and refitting the 1000 rpm driven pinion

Split the rear PTO housing from the centre housing.

Removal 
Place the PTO housing flat on a workbench.
Remove the block consisting of the clutch unit (15) and unit/driving pinion (23) assemblies. Take off:
- the circlip (26);
- the hub (11)/coupler (10)/circlip (27) assembly;
- the circlip (1);
- the driven pinion (18).
If necessary, remove the circlip (27) from the hub (11).


Refitting 
Clean and check all components. Replace any defective parts. Check that the central channel and the relevant radial port in the 1000 rpm output shaft are not obstructed; Lubricate the friction ring (1) of the driven pinion (18).


If necessary, refit a new circlip (27) on the hub (11). Refit:
- the driven pinion (18);
- a new circlip (1);
- the hub (11)/coupler (10)/circlip (27) assembly;
- a new circlip (26).
Refit the block consisting of the clutch unit (15) and unit/driving pinion (23) assemblies. Fit the PTO housing in a vertical position.
Assemble the rear PTO housing to the centre housing.

Removing and refitting the front bearing

Split the rear PTO housing from the centre housing.

Removal 
Note the orientation of the cylindrical roller bearing (24) in the centre housing. Extract this bearing. Remove the oil deflector (25).


Refitting
Clean and check all components. Replace any defective parts.
Refit the oil deflector in the bore of the centre housing.
Using a suitable locally made fitting drift, fit the cylindrical roller bearings in the centre housing, turning the rounded profile of its metallic cage towards the 1000 rpm output shaft (13). Manually check that the bearing is resting against the deflector. Assemble the rear PTO housing to the centre housing.

Removing and refitting the rear bearings and 1000 rpm output shaft

Split the rear PTO housing from the centre housing.


Removal 
Place the PTO housing flat on a workbench in order to allow removal of the 1000 rpm output shaft (13). If fitted, remove the sensor located on the lower right-hand side of the power take-off housing. Remove the 1000 rpm driven pinion (18). Loosen the screws (2).


Remove the rear bearing (22)/output shaft (13) assembly which consists of:
- the cassette seal (14);
- the O’ring (15);
- the shim(s) (23);
- the cup (21);
- bearing cones (3) (8);
- castellated washer (4);
- circlips (16) (17).
Remove the cup (19) from the rear PTO housing.
From the 1000 rpm output shaft (13), remove:
- the circlip (17);
- the bearing cone (3);
- the castellated washer (4);
- the bearing cone (8);
- the bearing cup (21);
- the circlip (16).
Strip the output shaft (13), removing:
- the bearing (22) with its cassette seal (14) and O’ring (15);
- the flange shaft (5) (if necessary).

Refitting 
Clean and check all components. Replace any defective parts. Check that the central channel and the relevant radial port in the 1000 rpm output shaft are not obstructed; Equip the output shaft (13) by refitting:
- the flange shaft (5). Tighten the screws (6) to torque;
- the rear bearing (22). If necessary, replace the cassette seal (14) and O’ring (15).
Refit on the 1000 rpm output shaft (13):
- the circlip (16);
- the bearing cup (21);
- the bearing cone (8);
- the castellated washer (4);
- the bearing cone (3);
- the circlip (17).
Refit the cup (19) on the rear PTO housing. Refit the original shim(s) (23) onto the bearing (22) only if the rear bearings do not need shimming.
The rear bearings must be shimmed if at least one of the following parts needs replacing:
- PTO housing;
- castellated washer (4);
- bearing cones and cups (3)(8) and (19)(21);
- rear bearing (22).
Refit the rear bearing (22)/1000 rpm output shaft (13) assembly on the PTO housing. Lightly smear the thread of the screws (2) with Loctite 242 or equivalent. Tighten these screws to a torque of 72 - 96 Nm.
Refit the driven pinion (18):
If necessary, refit the sensor located on the lower right-hand side of the power take-off housing. Moderately tighten the screw.
Fit the PTO housing in a vertical position.
Assemble the rear PTO housing to the centre housing.

Removing and refitting the flange shaft

The flange shaft may have 6, 20 or 21 splines.

Removal 
Remove off the protector (9).
Immobilise the 1000 rpm output shaft (13) using a locally made V screw (M12). Loosen the screws (6). Remove the flange shaft (5).


Refitting 
Check for the presence of the locating pin (35). Refit the flange shaft.
Immobilise the 1000 rpm output shaft. Insert and tighten the screws (6) to a torque of 120 - 160 Nm. Manually check the mobility of the 1000 rpm output shaft. Refit the protector.

Replacing the rear bearing cassette seal

Split the rear PTO housing from the centre housing.
Remove the rear bearings and strip the 1000 rpm output shaft.
Note the position of the cassette seal (14) in the rear bearing (22). Extract the cassette seal. Discard the O'ring (15).

Replacing the seal
Clean and check all components. Replace any defective parts.
Using the tool ref. 3378115M1, fit the cassette seal (14) in the bearing (22), turning the seal lip towards the inside of the PTO housing.
After fitting, check that the seal is positioned as indicated.


Fit a new O'ring (15) on the rear bearing (22).
Lubricate the inner rim of the cassette seal (14) and O’ring (15) with clean transmission oil. Recondition and refit the rear bearing (22) 1000 rpm output shaft (13) assembly on the PTO housing. Refit the driven pinion (18).
If necessary, refit the sensor located on the lower right-hand side of the power take-off housing. Moderately tighten the screw.
Fit the PTO housing in a vertical position.
Assemble the rear PTO housing to the centre housing.

Shimming the rear bearings

Split the rear PTO housing from the centre housing. Take off:
- the 1000 rpm driven pinion;
- the rear bearing (22)/1000 rpm output shaft (13) assembly;
- the bearing cone (19) from the PTO housing;
- the flange shaft (5) of the 1000 rpm output shaft (13).

Shimming


Note dimensions A and B. To avoid being hindered by the resistance of the cassette seal (14) on the 1000 rpm output shaft (13), the seal should be temporarily excluded during measurement of A and B dimensions.


Dimension A
Using a depth gauge, measure dimension A on the PTO housing.
Dimension B
- Rest the bearing/1000 rpm output shaft (13) assembly on the rear bearing block. This assembly comprises:
- bearing cones (3) (8) and their cup;
- castellated washer (4);
- circlips (16) (17).
- Ask an operator to exert a strong and constant manual pressure on the bearing cup (19). Simultaneously turn the 1000 rpm output shaft (13) from left to right so as to correctly "seat" the bearing cones in their cups.
- Measure dimension B at two opposing points. Take the average of the two measurements.
Calculate B - A. Depending on the result, select a thickness of shim(s) (23) to achieve a clearance J of 0.05 to 0.15 mm. If possible, shim so as to obtain minimum tolerance.


Refit:
- the flange shaft (5) of the 1000 rpm output shaft;
- the bearing cup (19) in the PTO housing;
- the rear bearing (22)/1000 rpm output shaft (13) assembly fitted:
- with a new cassette seal (14),
- with the shim(s) (23) selected during operation.
Lightly smear the thread of the screws (2) with Loctite 242 or equivalent. Tighten these screws to a torque of 72 - 96 Nm. Refit the driven pinion (18).
Assemble the rear PTO housing to the centre housing.