Monday, 10 September 2012

Rear axle - Lift cylinder supports


The lift shaft (7) fits into supports (2) (16) fitted to the centre housing. The lift shaft is splined at its ends and operates the arms (5) (15). The arm (5) is positioned by locating pin (4) inserted into cam (8), itself integral with the shaft via splines. The shaft drives the cam that informs the ELC calculator of the arm position via sensor (11). Each support is positioned by two locating pins (13) force fitted into the centre housing. Oil tightness of the bearings including friction bushes (10) is provided by seals (1) (3) inserted in both sides of the support.

Two types of assemblies are possible on the left-hand support:

Assembly 1
- On support (16), a channel "C" and a port "O", linked to the trumpet housings by external pipes, provide for air venting in the centre housing and trumpet housings via breather pipe (18).

Assembly 2
- On support (16), air venting in the centre and trumpet housings is solely ensured by channel "C" and breather (18).
- A plug (30) blocks the unused port.
- In both assembly configurations, an O�ring (19) between the housing and the support provides oil tightness for channel "C".
- Tractors also exist without hydraulic lift. In this case, a plate covers the location of the supports (2) (16).


The lower and lateral supports (1) of drawbars (7) are positioned by locating pins (3) and retained by bolts (4) on to the centre housing. Each support is fitted with a draft sensor (8) held by locking plate (2), spacers (6) and bolts (5). A guard (9) fixed to supports (1) protects the sensor harness.

Tightening torques
- Bolts (4) on supports (1) (Fig. 1): 480 - 640 Nm, Loctite 270
- Bolts (5): 50 Nm, Loctite 270.

Parts list
(1) Seal (2) Right-hand support (3) Seal (4) Locating pin (5) Right-hand side lift arm (6) Bolts and washers (7) Shaft (8) Cam (9) Bolts and washers (10) Friction bushes (11) Position sensor (12) Nut (13) Locating pins (14) Grease nipples (15) Left-hand side lift arm (16) Left-hand side support (17) Grooved spacer (18) Breather pipe (19) O�ring (30) Plug (31) O�ring (32) O�ring

Assembly types 

Assembly 1
- Tractors fitted with Heavy Duty trumpet housings with sealed compartment or composite drive units.
Assembly 2
- Tractors fitted with standard or double drive unit trumpet housings.

Cylinder attaching points

Layout of components
(20) Upper pins (21) Retaining pins (22) Cylinders (23) Washers (24) Grease nipples (25) Snap rings (26) Washers (27) Lower pins (28) Circlips (29) Friction bushes

Immobilise the tractor. Chock the front wheels. If necessary, chock between the fcylindere and the front axle. Remove the rear wheels or place them in the wide track position. Position axle stands as required. Remove the rear silent block bolts and slightly tilt the cab forwards, checking that nothing hinders this or touches the forward face of the cab.
- Access to the right-hand side support is difficult since one of the four retaining bolts is masked by the high-pressure pipe (1) of the lift control and auxiliary spool valves.
- To remove the support, disconnect this pipe that runs from the manifold on one hand, and the priority blocks on the other (depending on options).
Disassemble union (2).

Remove the position sensor (11).
Take out the upper pins (20) from cylinders (22) and the lift rod pins.

Removing and refitting the shaft

Take off breather pipe (18). Disconnect and remove the union screwed into port "O" on support (16) (depending on the assembly type).
Take out bolts (9) on each support. Using straps, sling together the pin, supports and lifting arm and remove them. Recover the O�ring (19).
Take out bolts (6). Remove the lift arms, noting their direction for reassembly. If necessary, extract bushes (29).


Remove the cam (8) and grooved spacer (17). Note the position of the supports (2) (16) and separate them from the shaft. Clean and check the components. Replace any parts found to be defective. Use protector, ref. 3378123M1. Slide support (16) onto shaft (7) in the position previously noted in operation. Proceed in the same way with support (2). Check for the presence of locating pin (4) on cam (8). On shaft (7), insert grooved spacer (17) and cam (8) in contact with their respective supports (2) (16).
If necessary, replace friction bushes (29) using pin (20) as an insertion tool.
Mark the position of locating pin (4) with a line of paint on cam (8) and arm (5).
Lightly coat the splined ends of the shaft with Antiseize grease or its equivalent. Refit the lift arms with the paint mark made previously on the arm (5) aligned with that on cam (8) and side "A" of the arm flush with side "B" of the pin. Assemble the washers and bolts (6) the threads lightly smeared with Loctite 270. Tighten to a torque of 240 - 320 Nm.
Check for the presence of locating pins (13) inserted into the centre housing at the location of each
support and O�ring (19) on the left-hand side support.
Using straps, correctly sling the assembly of pin, supports and lift arm and position them on locating pins (13).
Fit the washers on bolts (9) the threads lightly smeared with Loctite 270. Tighten to a torque of 240 -320 Nm.
Check that none of the channels in support (16) are obstructed. In the case of an Assembly 2 type, refit the plug (30) fitted with seal (31). On an Assembly 1 type, fit the hydraulic union and reconnect the pipe. On each type of assembly, check the cleanliness of breather pipe (18) and screw it fitted with O�ring (32) onto the left-hand side support. Manually check the axial clearance and the rotation of the shaft.

Disassembling and reassembling the supports 

On each support, remove seals (1) (3) and grease nipples (14).
Lightly smear the external diameter of seals (1) (3) with Loctite 542 and insert them using service tool, ref. 3378124M1, with the lip turned towards the outside of the support.


Fit the grease nipples (14). Refit the upper cylinder pins fitted with grease nipples (24) respecting the location of washer (23). Fit and adjust the position sensor. Refit union (2) on the manifold and reconnect the high pressure pipe (1) from the auxiliary and lift control spool valves that was disassembled in operation. If needed, place the cab on its rear supports. Tighten the bolts previously lightly smeared with Loctite 270 to a torque of 200 - 260 Nm. Refit the wheels or place them in their initial position. Remove the axle stands (if used). Tighten all nuts and bolts to their correct torque.


Using a grease gun, grease the supports (2) (16), and pins (20) (27).
Check the lift control operation. Check the oil tightness of pipe (1) and union (2).

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