GPA40 rear PTO - Disassembling and reassembling the driving gears



Legend 
540 - 1000 rpm PTO driving gears (2 speeds)
540 E PTO driving gears (3 speeds)

Disconnect the PTO housing from the centre housing.
Position the PTO housing horizontally, with the gears facing upwards.
Remove the selector rail(s).
Remove the 540 - 1000 rpm or 540 E driven gears (depending on version) of the lower PTO shaftline. This removal must be carried out so that unit B can then be removed.
Take unit B out of the PTO housing (shaft, driving gears, coupler(s) and tapered roller bearings). If necessary, drive out the bearing cups (4) (8) and the oil deflector (28), marking the direction in which they are fitted.
Strip unit B by carrying out the following:
- for the 540 - 1000-rpm PTO driving gears;
- for the 540 E PTO driving gears.

Remove the driving gears

540 - 1000 rpm PTO driving gears 
Remove the Vespel ring (30). Remove the bearing cone (7).
Remove the driving gear (11) and the coupler (5).


Extract the bearing cone (3).
Remove the spacer (1), the washer with flat section (23) and the driving gear (10). If necessary, drive out the oil restrictor (31) from the shaft (13) and discard the "O" ring (32).

540 E PTO driving gears 
Remove the Vespel ring (30). Remove the bearing cone (7).
Remove the driving gear (11) and the coupler (5).
Remove the bearing cone (3) and the "O" ring (29).
Remove the coupler (5) along with its hub (26).
Remove the driving gear (9), the shouldered ring (25) and the driving gear (10). If necessary, drive out the oil restrictor (31) from the shaft (13) and discard the "O" ring (32).


Check that the radial holes used to lubricate the gears and the calibrated hole of the oil restrictor (31) are not blocked. Lubricate the oil restrictor and the new "O" ring (32). Reassemble unit B by carrying out the following:
- for the 540 - 1000-rpm PTO driving gears;
- for the 540 E PTO driving gears.

Install the driving gears

540 - 1000 rpm PTO driving gears 
On the shaft (13), install:
- the oil restrictor (31) and a new "O" ring (32)
The oil restrictor (31) must be up against the shoulder of the shaft and its calibrated hole facing towards oil chamber C;
- the gear (10);
- the washer (23), with the larger surface positioned towards the gear;
- the spacer (1).
Using a press and a suitable fixture, Install the bearing cone (3) against the spacer (1). Slide the following onto the other end of the shaft (13):
- the coupler (5);
- the gear (11).
Using a press and a suitable fixture, Install the bearing cone (7) against the shoulder of the shaft. Check that the coupler (5) slides freely towards the 540 - 1000 rpm gears. Also check that these gears rotate freely. (see remove pic)

540 E PTO driving gears 
On the shaft (13), Install:
- the oil restrictor (31) and a new "O" ring (32)
The oil restrictor (31) must be up against the shoulder of the shaft and its calibrated hole facing towards oil chamber C;
- the gear (10);
- the shouldered ring (25);
- the gear (9);
- the hub (26);
- the coupler (5) (540 E);
- the "O" ring (29).
The "O" ring (29) prevents loss of hydraulic flow and helps improves the lubrication of the gear (9).

Reinstall the bearing cone (3).
Slide the following onto the other end of the shaft (13):
- the coupler (5) (540 - 1000 rpm);
- the gear (11).
Using a suitable fixture, Install the bearing cone (7) against the shoulder of the shaft. Check that each coupler (5) slides freely towards its respective gears (540 - 1000 rpm and 540 E). Also check that these gears rotate freely. (see remove pic)

Driving gears for 540 - 1000 rpm or 540 E PTO
Reinstall unit B into the PTO housing (shaft, driving gears, coupler(s) and bearings).
If the bearing cups (4) (8) and the deflector (28) were driven out of their housing during disassembly, Install:
- the deflector by positioning it.
The oil deflector has a calibrated hole for lubricating the bearings (7)(8);
- the bearing cups (4) (8) against their respective shoulders.
Shim the bearings (3)(4) and (7)(8) of the layshaft (13).
Reinstall the 540 - 1000 rpm or 540 E driven gears of the lower PTO shaftline.

Reinstall and adjust the selection mechanism.
Reconnect the PTO housing to the centre housing.
Start the tractor engine and check the rear PTO operation.

Shimming the layshaft bearings

Fig A : 540 - 1000 rpm PTO driving gear layshaft bearings
Fig B : 540 E PTO driving gear layshaft bearings

Preparing for shimming 
For easier access to the driving gears and to prevent inertia created by rotation of the driven gears, it is advisable to carry out J1 shimming while temporarily excluding the following:
- the 540 - 1000 rpm or 540 E driven gears (depending on version) of the lower PTO shaftline;
- the selector rail(s) and fork(s);
- the lower shaftline lubrication pipe.


Lightly lubricate the bearing cones (3) (7) with clean transmission oil.
Check that the deflector (28) and the bearing cup (8) are present in the PTO housing. Install the driving gears into the housing.
Remove the shim(s) (27) located in the bore of the bearing cup (4) of the removable support (12). Reduce shim thickness by approx. 0.10 mm and reinstall it/them in the place from which it was/they were removed.
Install the cup (4). Temporarily fix the removable support (12) to the PTO housing. Tighten a few opposing V screws to 68-92 Nm.

Shimming
Place a dial gauge feeler pin at the end of the shaft (13).
Push firmly on the driving gear assembly, turning it alternately to the right and left to correctly Install the cones in their bearing cups.
Set the dial gauge to zero.

A

According to the temporary clearance reading on the dial gauge, determine another shim (27) thickness to obtain a final clearance (Fig A or B) depending on version): J1 = 0 to 0.10 mm.
As far as possible, shim to the minimum tolerance.

B

Install and adjusting the cable controls

540 - 1000 rpm cable control

Install the cable at the cab end 
Tighten the clevis (2) to the maximum against the cable (4). Tighten the nut (3). Position the lever (1) located on the console in neutral (N).


Install the cable to the lever. Tighten the sheath end on the support.
Position the feed-through conduit on the cab floor.

Installing the cable at the PTO housing end 
Tighten the ball joint (2) to the maximum against the cable (3). Tighten the nut (5). Position the rod (1) (540 - 1000 rpm) located to the left of the PTO housing in neutral (N). For easy access to the left-hand side of the PTO housing, position the linkage arms in the raised position.


If the tractor is fitted with a 540 E PTO power take-off,  it is recommended to place it in neutral before activating the 540 - 1000 rpm power take-off PTO.
Slide the sheath end of the cable onto the support. If possible, use nuts (4) to make the thread length identical on either side of the support.
Tighten the nuts. Fix the ball joint (2) on the rod.

Checking the correct engagement of the 540 - 1000 rpm gears
Check that gear engagement takes place normally in each lever position (540 - 1000 rpm and neutral) and that there is no sign of the cable being pinched. If this is not the case, move the sheath end until the correct adjustment is obtained.

540 E cable control (if fitted)
The control lever (1) (540 E) is located on the console, to the right of the 540 - 1000 rpm leverThe 540 E economy version follows the basic concept of the 540 - 1000 rpm version and is completed by a set of additional gears (driving and driven). The 540 E control is mechanically engaged by placing the 540 - 1000 rpm control in neutral first.


 Installing the cable at the cab end 
Tighten the clevis (2) to the maximum against the cable (4). Tighten the nut (3). Position the lever (1) located on the console in neutral (N).
Install the cable to the lever. Tighten the sheath stop on the support.
Position the feed-through conduit on the cab floor.

Installing the cable at the PTO housing end 
Tighten the ball joint (2) to the maximum against the cable (3). Tighten the nut (5). Position the rod (540 - 1000 rpm) in neutral. Position the rod (1) (540 E) located to the right of the PTO housing in neutral. For easy access to the right-hand side of the PTO housing, position the linkage arms in the raised position.


Slide the sheath end of the cable onto the support. If possible, use nuts (4) to make the thread length identical on either side of the support. Tighten the nuts. Fix the ball joint (2) on the rod.

Checking the correct engagement of the 540 E economy gear
Check that gear engagement takes place normally in each lever position (540 E and neutral) and that there is no sign of the cable being pinched. If this is not the case, move the sheath end until the correct adjustment is obtained.