EPS Motor Replacement

EPS Motor Replacement

NOTE: During removal/installation, do not allow dust, dirt, or other foreign materials to enter the gearbox.

1.Remove the steering gearbox.

2.Remove the motor (A) and O-ring (B) from the gearbox.


3.Clean the mating surface of the motor and gearbox.

4.Apply a thin coat of silicone grease to the new O-ring, and carefully fit it on the motor.

5.Apply steering gear grease around the worm shaft (C).

6.Install the motor on the gearbox by engaging the motor shaft and worm shaft. Note the motor installation position (direction of motor wires (D)).
Before tightening the bolts, turn the motor 2 or 3 times right and left about 45 degrees and check for close contact at the mating surface of the motor. Loosely tighten the bolts. Then, holding the motor head firmly, tighten the bolts alternately to tighten the motor seccurely.

There must be no foreign material and O-ring trapped in the mating surfaces and there must be no loose contact (lift) at the surfaces.

7.Install the steering gearbox.

8.After installation, start the engine, and let it idle. Turn the steering wheel from lock-to-lock several times. Check that the EPS indicator does not come on.

NOTE: When the motor is replaced, perform the following check after installing the gearbox.

The motor can be deteriorated if there is abnormal sound or vibration from the motor during checking under the following conditions. Replace the motor with a known-good motor and recheck.

-1 Park the vehicle outdoors.

-2 Set the wheels on the normal asphalt road.

-3 Start the engine.

-4 Turn the steering wheel two or three turns at a speed of one turn per second.
Low tone roaring or booming noise is heard larger than the engine noise. (The noise must be smaller then the engine noise and it must not be noticeable very much. )

-5 Turn the steering wheel 45° to 90° and hold it in the position, then return the steering wheel slowly to the straight driving position.
Hissing noise can be heard or vibration is noticed with the hands. (On normal motor, the sound and vibration must be very small. )