Specifications, Service and Repair of Farm and Lawn Tractors

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MF 3080, 3105 Tractor Gearbox - Selector rail and forks


The selector rail (7) which supports the various forks and the latch assembly is located on the RH side of the MF 3080, 3070, 3115, 3125 Tractor gearbox on the selector cover side. It crosses the gearbox housing and the Hare/Tortoise range control piston (13). It is held in place by a set screw(8).

A plug (9) seals the front end of the rail and a cover (15) seals the rear end.

The forks for the A/B range (4), 1st/2nd gears (5), 3rd/4th gears (6) and the creeper gears (28) cannot be adjusted (except locking pressure for the creeper gears). The Hare/Tortoise range fork (20) is adjustable. Note: The 4x2 gearboxes (8-speed) have no A/B fork (4).

MF 3080, 3105 Tractor Creeper gear fork



Fig. 1

Disassembly:

- Disconnect the creeper gear control cable.

- Remove the bolt (1), withdraw the rod (2) to disengage the lever from the fork (Fig. 1).

- Unscrew nut (26) and the locking screw (27) on the fork (28) (Fig.2).

- Remove the setscrew (8) (Fig. 5)

- Turn the selector rail (7) and drive out the roll pin (29).

- Take care not to let the roll pin fall into the gearbox housing.

- Drive out the double pin (1) from the coupling sleeve (2) (Fig. 4). If the pin is inaccessible.



Fig. 2



Fig. 4

On MF 3080, 3105 4WD tractors:



Fig. 5

- Disconnect the front hose from the differential lock control (front axle side).

- Remove the guard (1) (Fig. 6).

- Unscrew the centre bearing (2) from the 4WD shaft (3) (Fig. 6).

- Remove the split pin (4) from the rear sleeve (5), disengage the 4WD clutch shaft by sliding off the sleeve (Fig. 6). Turn the halfshaft to bring the coupling sleeve (2) into position (Fig. 4).

- Fit the setscrew (8) temporarily to hold the selector rail in order to remove the fork (28) (Fig. 5)

- Slide the sleeve (1) and the coupler (2) towards each other on the connecting shaft (3) (Fig. 7).

- Move the sleeve assembly, connecting shaft and coupler to the outer LH edge, then withdraw it from the fork (28) (Fig. 7).

- Mark the direction in which the sleeve is assembled (1) (Fig. 7).

- Remove the fork (28) from the selector rail (7).

- Remove the rod (3) (Fig. 1).

- To remove the creeper gear control shaft (1), turn it so that it goes under the selector rail (7) (Fig. 9). Discard the 'O' ring (3).



Fig. 6



Fig. 7

Reassembly:



Fig. 9

- Check the parts and replace any which are faulty.

- Refit the control rod. Pull the rod as far as possible to the right. Lubricate and fit a new 'O' ring. Refit the rod(3).

- Coat the bolts with Loctite 241 and tighten them. Refit the fork on the selector rail.

- Ensure that the lever (1) of the creeper gear control rod faces the front of the tractor.

- Engage the sleeve assembly, connecting shaft and coupler at the LH outer edge, then fit it in the fork.

- The machining groove on the sleeve (1) should face the rear of the tractor.

- Slide the sleeve and the coupler on to the connecting shaft.

- Press a new double pin (1) into the sleeve. Remove the setscrew.

- Press in a new pin (29) and turn the selector rail (7).

- Clean the setscrew (8), coat it with Loctite 542 and tighten to a torque of 28 - 43 Nm.

- Locate the fork (28) and the locking screw (27) on flat M of the selector rail (7) (between the two detent notches).

- Tighten the screw to compress the ball. Slacken the screw a quarter turn. Clean the nut (26) and coat it with Loctite 241, then tighten to a torque of 15 -20 Nm. Check that the fork is correctly tightened.

- Turn and push the rod (2) to engage the lever in the fork. Fit the bolt after coating with Loctite 241. Check the operation of the rod.

- Reconnect and adjust the creeper gear control cable.

- Check that the transfer pipe 'O' rings are in good condition and insert the pipe into the LH cover.

- Refit the RH cover and the bolts. Tighten to a torque of 72-96 Nm.

- Carry out procedures in reverse.

- Fit the wiring harnesses and secure with a clip.

- Refit the trailer braking valve (if fitted). Check that the O-rings are in good condition. Tighten to a torque of 25-35 Nm.

- Carry out procedure 6 in reverse. Refit the trailer braking valve pipe (if fitted) and the filter.

- Carry out procedures 9 - 12 in reverse. Refit the wheel. Remove the stand and the trolley jack.

- Tighten the wheel nuts to a torque of 400 - 450 Nm.

- Start the engine and carry out procedures.

- Road test the tractor and check the creeper gear control.

Disassembly with or without creeper gears of MF 3080, 3105 Tractor Gearbox Selector rail and forks

For MF 3080, 3105 Tractor gearboxes fitted with creeper gears, carry out the additional procedures marked.

- Disconnect the creeper gear control cable.

- Remove the plugs (1), the springs (2) and the detent plungers (3) (Fig. 5). Refit the setscrew (8) temporarily.

- Tap the rear end of the selector rail (7) with a copper tipped mallet to drive out the plug (9).

- This procedure gives access to the selector rail from the front. Remove the creeper gear fork (28) (Fig. 5) by moving the selector rail forwards.

- Position the Hare/Tortoise range fork (20) in the Low position.

- Remove the adjusting screws (19). Remove the bolts (16) and the cover (15).

- Remove the Hare/Tortoise piston (13) and discard the seals.

- Remove the cylinder (10) and discard the seal.

- Turn the pump suction pipe (1) upwards. Do not slacken the bolt (2) on the pipe clip,

- Move the selector rail rearwards to tree the A/B (4x4 gearbox), 1st, 2nd, 3rd. 4th and Hare/Tortoise forks.

- Withdraw the 1st, 2nd, 3rd and 4th forks and the lock assembly.

- Withdraw the Hare/Tortoise fork. Remove the slider (18) (Fig. 7).

- Withdraw the selector rail through the selector cover access panel after passing it through the High/Low range cylinder bore .Remove the lock assembly.

Reassembly:

- Check the parts and replace any that are worn. Clean the cone threads and the nut tapping.

- Refit the latch assembly. Refit the forks and the latch assembly.

- Check that the ports of the Hare/Tortoise range hydraulic cylinder (10) are not blocked.

- Fit the cylinder complete with the O-ring (11).

- Slide the selector rail forwards into the Hare/Tortoise range fork, the latch assembly, 1st/2nd, 3rd/ 4th and the A/B range forks (4x4 gearbox). Note: For MF 3080, 3105 Tractor gearboxes fitted with creeper gears, move the selector rail far enough forward to refit the fork (28).

- Fit the cover (15) with the bolts (16) and tighten to a torque of 27 - 32 Nm.

- Fit the creeper gear fork lugs into the coupler. Note: The fork control lever (1) should face for-wards.

- Slide the selector rail rearwards into the creeper gear fork.

- Press in a new pin to facilitate fitting, turn the selector rail.

- Clean the setscrew, coat it with Loctite 542 and tighten to a torque of 38 - 43 Nm.

- Coat the plug (9) with Loctite 542 and press it in level with the housing.

- Fit the locking screw (27) on the fork (28) and nut (26) on the bolt.

- Turn and push the rod (2) until it engages with the lever in the fork. Fit the bolt (1) after coating it with Loctite 241.

- Fit the detent plungers, springs and locking nuts. Tighten the nuts to a torque of 50-70 Nm.

- Fit the plunger and the hydraulic spool valve (4x4). Reconnect and adjust the creeper gear control cable.

- Carry out procedures in reverse. Refit the wheel. Remove the stand and the trolley jack.

- Tighten the wheel nuts to a torque of 4C0 - 450 Nm.

- Top up the oil in the gearbox, remove one chocks and release the parking brake.

- Road test the following controls: Creeper gears (if fitted). Hare/Tortoise range. 1st, 2nd; 3rd, 4th gears.

- Check all cover gasket faces and hydraulic unions for leaks.

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