Valve body repair using valves in standard + size 4T65E (Volvo XC90, S80)

4T65E is an automatic 4-speed transmission manufactured by General Motors, developed in 1993 and was originally installed only on GM cars - Chevrolet Impala, Camaro, Malibu, some BUICK and Pontiac models. The box turned out to be extremely reliable and successful, moreover, it was actively modernized until 1998, since 1999 it began to be installed on the popular Volvo XC90 and S80, which, 22 years later, make up a significant share of the European auto market.

4T65E works without problems for 5-7 years, or 100-200 thousand km. mileage (depending on the operating conditions, of course), but then - there is a need for overhaul, since absolutely all transmission units wear out - steel and friction plates, pistons, bushings, an oil pump, a torque converter, a valve body - we will tell you about the repair of the latter today , since the repair of the hydraulic control unit is an integral part of the overhaul of any automatic transmission.

You can identify the problem with the 4T65E valve body by the following most common signs:

• Computer diagnostics show errors 0741 and 0742
• Shocks when shifting from first to second and from second to third gear

To repair the valve body, we will use consumables of our own production, namely a new line of NO-REAM valves for 4T65E. Their distinctive feature is the ability to install the valve without reaming the holes, it is enough to remove the old valve and immediately install the new one. Let's start repairing!
 

Valve body repair. Valve replacement.

                                                                                                        This is how disassembled valve body 4T65E looks like

Let's start the block repair from the plate in which the Actuator Feed Limit valve and the 3-4 Accumulator are located (in the photo above, this plate is on the right)

• The Actuator Feed Limit Valve is responsible for regulating the pressure of the transmission fluid that goes to the pressure regulator solenoid and the solenoids responsible for 1-2 and 3-4 gears. If the valve or channel has a run-out - error 1811 awaits us, switching will occur with a delay, the torque converter will not be unlocked in time, and this can lead to damage to the lock-up valve.
• 3-4 Accumulator Piston - an age problem 4T65E, the piston works on a steel guide, a depletion appears along the inner diameter of the piston, which leads to such problems - unstable shifts 3-> 4, complete disappearance of 4th gear. If the problem is not eliminated in time, the 4th gear clutch package will burn out.

                                                                                                            Piston play 3-4 is easily determined visually

Vacuuming Valve Actuator Feed Limit, at 15 "Hg it must necessarily be replaced.

                                                                                                                        We remove the old valve, install a new one and repeat the vacuum test.

The tightness was restored, and a good result was obtained.

Now we disassemble the 2-3 battery case 

On the left is an old piston, on the right is a new one. It is almost impossible to find an O-ring of decent quality, so we take the old one (often in good condition) and install it on a new piston.

We collect the battery

We pass to the main plate of the valve body. We are testing the 2-3 Accumulator valve, if this valve fails, we will have problems with switching 2-3 and burnt clutch packs.

We take out the old valve and the booster and replace it with a new set.

We test a new set of valves 2-3, we get an excellent level of vacuum.

We check the valve 1-2 Accumulator - as the name implies, it is responsible for switching from the first to the second, in case of wear, there will be blows or slippage when switching.

Installing  a new 1-2 Accumulator Valve

Testing confirms successful valve replacement

Now the main booster valve. Problems with it are indicated by symptoms such as slipping when switching (especially 1-2) and a long load R

Installing a new set of booster valve

Tightness restored

TCC Apply Valve, responsible for blocking the torque converter

Replacing for a new one and repeat the vacuum test

The last valve we will replace in this block is the 4-3 Manual Downshift, which also has critically low vacuum values. Usually, its failure is accompanied by the absence of 3rd and 4th gears.

Replacing for a new one

The vacuum values are excellent. This is where we have finished with the hydraulic part of the unit and move on to the solenoid valves, solenoids.

Checking solenoids on the stand

Everything is simple here, the 4T65E solenoids are not repairable, flushing is also only a temporary solution to the problem, so we act according to this algorithm - if testing at the stand indicates a malfunction of the solenoid, it must be replaced with a new or guaranteed working used version.

We check all the solenoids, change them to new ones if necessary, assemble the block. This is how a complete repair of the 4T65E valve body looks like, it is carried out in 1 working day and we give a 1 year warranty.
The parts that we used for this repair can be found and purchased at the link below:

• Valves in standard+ size for 4T65E