Trailer Hitch Motor: Service and Repair
WM 666419 Removing and installing motor for trailer hitch
Technical values
Preliminary work
1. Remove the spare wheel holder on vehicles with an externally fitted spare wheel. -> 445619 Removing and installing spare wheel mount (frame) - "Removing" section 44561903 Removing and installing spare wheel mount (frame)
2. Remove trailer hitch. -> 669019 Removing and installing trailer hitch - "Removing" section Service and Repair
Removing motor for trailer hitch
Overview of motor for trailer hitch
1. Cut open the bonded joint -Arrows A- with a knife -a- and remove the cover -Arrow B-.
Cutting open bonded joint and removing cover
2. Unclip line -arrows-.
Unclipping line
3. Unscrew the fastening pin -Arrow 1-.
Loosening fastening elements
4. Unscrew the fastening nuts -2- and remove the fastening screws -arrows 3-.
Loosening fastening elements
5. Loosen fastening flange -Arrow A- and remove locking pins -Arrow B-.
Loosening fastening flange and removing motor
6. Turn the coupling head into extended position as far as the stop -arrow C-.
Loosening fastening flange and removing motor
7. Swivel the motor inwards -arrow D- and remove it -arrow E-.
Loosening fastening flange and removing motor
Installing motor for trailer hitch
Information
- Before installing the motor, grease the ball joint -a- and the thread of the spindle with multi-purpose graphite grease.
Ball joint - flange connection
- Align the fastening flange -b- to the bore of the locking peg -c-.
1. Turn the coupling head into extended position as far as the stop -Arrow A-.
Installing and fastening motor
2. Push the motor with the electrical wire from the inside into the fastening flange -arrow B-. Swivel the motor outward while pushing it in -arrow C-.
Installing and fastening motor
3. Grease the locking pin with multi-purpose graphite grease for better adhesion, insert it into installation position -arrow D- and push back the fastening flange -arrow E-.
Installing and fastening motor
4. Insert the fastening screws -Arrows 3- , screw on the fastening nuts -2- and tighten the motor. => Tightening torque: 4.5 Nm (3.5 ftlb.)
Installing fastening elements
5. Guide the joint into the prongs and insert the bottom -d- and top -e- spacer rings.
Installing fastening elements
6. Apply medium-strength screw locking lacquer to the thread of the fastening pin -arrow 1- and screw in and tighten the fastening pin -arrow 1-. => Tightening torque: 50 Nm (37 ftlb.)
Installing fastening elements
7. Clip in the wire -arrows-.
Clipping in wire
Information
- Stick on the cover with Sicaflex 252.
- After sticking on the cover, allow the adhesive to dry for about 60 minutes.
8. Apply adhesive -Arrows A- to the cover and stick on the cover -Arrow B-.
Sticking on cover
Initialising final deactivation
Information
- After the motor is replaced, the limit stops must be re-initialised.
- If the limit stops are not initialised, the two LEDs on the switch flash at the same time.
- Once initialisation is completed successfully, the upper LED lights up in the retracted state, while the lower LED is continuously lit in the extended state.
1. Extend the trailer hitch until the limit stop is reached and the motor switches off automatically. Keep the switch pressed when doing this.
2. Retract the trailer hitch until the limit stop is reached and the motor switches off automatically. Keep the switch pressed when doing this.
Subsequent work
1. Install trailer hitch. -> 669019 Removing and installing trailer hitch - "Installing" section Service and Repair
2. Fit the spare wheel holder on vehicles with an externally fitted spare wheel. -> 445619 Removing and installing spare wheel mount (frame) - "Installing" section 44561903 Removing and installing spare wheel mount (frame)