Case IH 65 – Transmission Control Unit (TCU) or PTO Control Module: Worn pto brake or failed and burnt pto clutch pack

Severe mechanical and hydraulic failure within the Power Take-Off (PTO) assembly. This includes a burnt PTO clutch pack causing slipping or failure to engage, or a worn PTO brake causing the shaft to free-spin when disengaged.

• MX Maxxum
• 7110
• 7120
• 7130
• 7140
• 7150
• 7210
• 7220
• 7230
• 7240
• 7250
• 8910
• 8920
• 8930
• 8940
• 8950
• 5120
• 5130
• 5140
• 5150
• 5220
• 5230
• 5240
• 5250
• MX80
• MX90
• MX100
• MX110
• MX120
• MX135
• 55C
• 65C
• 75C
• 706
• 1486
• 585
• 685

1. 1

   Check the battery and charging system, as low voltage can prevent the PTO clutch solenoid from engaging fully.

2. 2

   Test the PTO clutch coil resistance with a multimeter (a healthy coil reads 2 to 4 Ohms; readings below 2 Ohms indicate a failing clutch drawing too much amperage).

3. 3

   Perform a hydraulic pressure test by hooking a test gauge to the PTO hydraulic test port. Low pressure causes the clutch pack to slip and burn, indicating a possible failing PTO hydraulic pump or leaking Teflon seal.

4. 4

   With the tractor off and the PTO disengaged, try to spin the PTO shaft by hand. If it spins freely with no resistance, the PTO brake piston or brake pad material is completely worn out.

1. 1

   Drain Fluids

   Drain the transmission and rear housing hydraulic oil.

2. 2

   Remove the PTO Unit

   Remove the 3-point hitch upper link bracket/cover to aid in shaft alignment. Unbolt the PTO unit from the rear frame and pull it straight back to disengage the drive shaft. Take care not to damage the oil suction tube.

3. 3

   Mount the Unit

   Stand the removed PTO unit upright on its 540 output shaft (using long bolts in the top rear threaded holes as legs).

4. 4

   Remove Pump Housing

   Remove the bolts attaching the bell-shaped pump housing to the unit and lift it off.

5. 5

   Access the Clutch Pack

   Compress the brake piston springs that push the clutch carrier up against the snap ring. Remove the snap ring, then pull the clutch carrier drum up and off the splines.

6. 6

   Replace Seals

   Inspect the Teflon seal rings on the drum. If replacing, warm the new Teflon seals in hot water to stretch them over the drum, then re-compress them.

7. 7

   Inspect and Replace Brake Pistons

   Remove the bolts holding the rear cover to the valve housing. Inspect the three brake pistons. If there is less than 3/32" of brake pad material remaining on the end of the pistons, they must be replaced.

8. 8

   Replace Clutch Pack

   Remove the burnt friction discs and warped steel separator plates. Install the new clutch pack components in the correct alternating order.

9. 9

   Reassembly

   Reassemble the valve body, clutch carrier, and pump housing. Ensure all O-rings and dowel pins are properly seated. Reinstall the complete PTO unit into the tractor and refill the hydraulic fluid.