Intermediate shafts GPA30 rear PTO - Driving pinions


The upper shaftline of the GPA30 transmission rear PTO transmits engine speed to the driving pinions through:
- a multidisc clutch and
- a series of three shafts:
- the mainshaft (19) splined to the vibration damper, itself screwed to the engine flywheel;
- the primary shaft (14) splined to the mainshaft and in front of the hydraulic pump (Load Sensing) drive pinion;
- The secondary shaft (28) is splined at the front on the hydraulic pump drive pinion and at the rear on the multidisc power take-off clutch.

Description and layout of the rear PTO driving pinions

Driving pinions for 2 speed PTO with interchangeable output shaft (version A)

Parts list 
(1) Hydraulic pump drive pinions (Load Sensing) (2) Bearing cone (3) Bearing cup (4) Cover (5) Shim(s) (6) Unit (7) Bearing cone (8) Bearing cup (11) Double driving pinion (12) Circlip (14) Primary shaft
(15) Clutch unit assembly (19) Mainshaft (23) Unit/driving pinions assembly (27) Screw (28) Secondary shaft

Driving pinions for 2 speed PTO with jaw coupler on output shaft (version B)

Parts list 
(1) Hydraulic pump drive pinions (Load Sensing) (2) Bearing cone (3) Bearing cup (4) Cover (5) Shim(s) (6) Unit (7) Bearing cone (8) Bearing cup (9) 540 or 750 rpm driving pinion (11) 1000 rpm driving pinion
(12) Circlip (14) Primary shaft (15) Clutch unit assembly (19) Mainshaft (23) Unit/driving pinions assembly (27) Screw (28) Secondary shaft

Driving pinion for 1000 rpm PTO (version C)

Parts list 
(1) Hydraulic pump drive pinion (2) Bearing cone (3) Bearing cup (4) Cover (5) Shim(s) (6) Unit (7) Bearing cone (8) Bearing cup (10) Spacer (11) 1000 rpm driving pinion (12) Circlip (14) Primary shaft
(15) Clutch unit assembly (19) Mainshaft (23) Unit/driving pinion assembly (27) Screw (28) Secondary shaft

Exploded view of driving pinions (versions A, B and C)

Parts list 
(2) Bearing cone (3) Bearing cup (4) Cover (5) Shim(s) (6) Unit (7) Bearing cone (8) Bearing cup (9) 540 or 750 rpm driving pinion (version B) (10) Spacer (version C) (11) Double driving pinion (version A) (11) 1000 rpm driving pinion (versions B and C) (15) Clutch unit assembly (23) Unit/driving pinions assembly (27) Screw

Split the PTO housing from the centre housing to gain access to the following main components:
- clutch unit (15) and unit/driving pinions (23) assemblies;
- cover (4);
- bearing cones and cups (2)(3) and (7)(8).

Removing - refitting the driving pinions and bearings

Remove the block consisting of the PTO clutch (15) and unit/driving pinions (23) assemblies from the PTO housing. Split assembly (15) from assembly (23).

Removal

On the unit/driving pinions assembly (23) (version A)


Take off:
- the bearing cone (7);
- the screws (27);
- the cover (4),
- the shim(s) (5).


Take out the double driving pinion (11) from unit (6).
If necessary:
- Drive out the bearing cups (3) (8);
- extract the bearing cone (2) from the clutch unit assembly (15).

On the unit/driving pinions assembly (23) (version B)


Take off:
- the bearing cone (7);
- the screws (27);
- the driving pinion (9)/bearing cone (2);
- the cover (4),
- the shim(s) (5).

On the driving pinion (11) from unit (6).
If necessary:
- Drive out the bearing cups (3) (8);
- extract the bearing cone (2) from the driving pinion (9).

On the unit/driving pinion assembly (23) (version C)


The servicing method for the unit/driving pinion assembly (23) of version C is similar to that applied for the unit/driving pinions assembly (23) of version B. The spacer (10) simply replaces the driving pinion (9).

Refitting

Clean and check all components. Replace any defective parts.

On the unit (6) (version A)
If disassembled, fit cups (3) (8) in cover (4) and unit (6) respectively.


Refit:
- the driving pinion (11);
- the shim(s) (5), only if the bearing do not need shimming. Otherwise, temporarily exclude this (these) shim(s);
- the cover (4),
- the screws (27);
- the bearing cone (7).
If disassembled, fit bearing cone (2) onto the clutch unit assembly (15) using a press and a suitable fixture; If necessary, shim the bearings.

On the unit (6) (version B)
If disassembled, fit cups (3) (8) in cover (4) and unit (6) respectively.


Refit the driving pinion (11) in the unit (6), with the offset "D" turned to face the cover (4)Refit:
- the shim(s) (5), only if the bearing do not need shimming. Otherwise, temporarily exclude this (these) shim(s);
- the cover (4),
- the screws (27);
- the bearing cone (7).
If removed, fit the bearing cone (2) on the driving pinion (9), using a press and a suitable tool. If necessary, shim the bearings.

On the unit (6) (version C)
The servicing method for the unit (6) of version C is similar to that applied for the unit (6) of version B. The spacer (10) simply replaces the driving pinion (9).


Reassemble the clutch unit (15) and unit/driving pinions (23) assemblies.
Refit the block consisting of the PTO clutch (15) and unit/driving pinions (23) assemblies from the PTO housing.

Removing - refitting the shafts

Removal

Mainshaft (19)
Disassemble the tractor between the engine and the gearbox. Remove the mainshaft. 

Primary shaft (14)
Split the tractor between the gearbox and the intermediate housing (Cab integral with centre housing). Remove the primary shaft.

Secondary shaft (28)
Split the rear PTO housing from the centre housing. Remove the secondary shaft.

Refitting

Mainshaft (19)
Refit the mainshaft. Assemble the tractor between the engine and the gearbox.

Primary shaft (14)
Refit the primary shaft. Assemble the tractor between the gearbox and the intermediate housing (Cab integral with centre housing).

Secondary shaft (28)
Refit the secondary shaft. Assemble the rear PTO housing to the centre housing.

Shimming the bearings


Temporarily exclude the original shims (5).
Temporarily reassemble the clutch unit (15) and unit/driving pinions (23) assemblies.


Temporarily attach the cover (4) onto the unit (6) using the four original screws (27) and locally made nuts (14).
Immobilise the unit/driving pinions assembly (23) in a vice with protective jaws.


Shimming 
Place the dial gauge feeler pin at the end of the sleeve (10).
Pull very hard on the clutch unit assembly (15), while turning it from left to right, in order to “seat” the bearing cone (7) correctly in the cup (8).


Set the dial gauge to zero.
Repeat operation, pushing hard to correctly seat the bearing cone (2) in the cup (3). Measure the clearance with the dial gauge.
Depending on the clearance measured, select a thickness of shim(s) (5) to obtain a clearance of J = 0 to 0.10 mm. If possible, shim so as to obtain minimum tolerance. Split the clutch unit assembly (15) from the unit/driving pinions assembly (23).
Slide the definitive shim(s) (5) selected during operation between the unit (6) and its cover (4). Definitively reassemble the clutch unit (15) and unit/driving pinions (23) assemblies. Allow for refitting assemblies (15) and (23) onto the PTO housing. Assemble the rear PTO housing to the centre housing.