Forward Clutch drum regeneration TOYOTA AC60E AC60F

Correct pressure distribution in hydromechanical automatic transmissions plays a key role in correct gear shifting.

Almost all automatic transmission clutch drums are structurally the same:

• 1. The input shaft and Forward Clutch drum are welded together to form one piece.
• 2. Pistons, which, when pressure is applied, activate the clutch pack, transmitting torque in accordance with the selected gear.
• 3. Set of steel and friction discs.
• 4. Thrust plate, as a rule, the thickness of this disc is always greater than the other steel discs of the clutch pack. Since it accounts for the lion's share of the pressure, which is provided by the hydraulic piston pressing on the clutch pack.
• 5. A retaining ring that serves as a stop for the thrust disk and secures the entire clutch pack.

Fixation of the retaining ring in the drum is implemented in the form of milling on the inner wall of the drum. This design is as simple as possible to manufacture and further maintain the transmission.

But this solution weakens the drum structure at the location where the locking ring is installed. This is not a problem and does not cause any problems under normal operating conditions and provided that all transmission components operate correctly.

A common problem that often occurs in TOYOTA AC60E transmissions used on Toyota Hilux 2.8L, Fortuner 2 (AN160), Hilux 8 (AN120), LC Prado 150 (J150) cars is associated with incorrect operation of the valve body and, as a result, high pressure in the Forward Clutch package .

High pressure also has destructive power. As a result of incorrect operation of the valve body and the supply of too high pressure to the clutch locking piston of the Forward Clutch drum, the discs are too tightly closed together, which looks like a blow to the retaining ring that secures the clutch pack in the drum. The force of such impacts may vary depending on the degree of damage to the drum.
During the process of disassembling and troubleshooting a transmission, you can often see physical damage to the Forward Clutch drum housing, in the form of a crack or, in some cases, tearing off part of the housing around the circumference of the retaining ring seat.

Further operation of such a drum is not possible; it must be replaced. The price of a new drum varies from $600 to $800.

The MAKTRANS company offers a drum regeneration service, the price of which is several times lower than buying a new one and amounts to $150.

How is the regeneration process going?