Removal and Replacement
91-130 Removing And Installing Backrest Lock On Front Seat
Reinstall in opposite order. Before installing the flexible drive shaft, check the adjustment and function of the backrest (see backrest lock- inside of seat).
Installation note
The thread on the gear screw is micro-encapsulated and must be replaced after removal or coated with screw securing agent.
Tightening torque: 35 Nm.
Check function of automatic locking system (see 91-151, items 10-13).
Removal, installation
Inside of seat
1 Press off and remove trim.
2 Disconnect connector S52/2x1 and expose wire to microswitch S52/2.
3 Unscrew retainer (7) for electrical wire and remove.
4 Unscrew bracket and remove flexible drive shaft on left and right of gear drive shafts.
5 Unscrew screws on motor (M25m5) for backrest adjustment (arrows).
6 Release tension on toothed belt and remove.
7 Disconnect control cable (2) on backrest lock (4). Remove retainer and plastic washer on backrest hinge bolt, inside.
8 Unscrew bolts on inside and outside of backrest gear (8) (2 each), 12 mm Allen wrench. Observe installation note.
9 Remove backrest lock (4) with gear on backrest hinge bolt by actuating release lever on lock (arrow).
10 Remove clamping pin for holding gear spindle (diameter 3 mm).
11 Unscrew gear spindle on backrest lock (4) and remove gear (8).
12 Screw gear spindle into backrest lock until clamping pin can just be knocked in (arrow).
13 Install clamping pin (total length 30 mm).
14 Insert backrest lock (4) with gear into front seat backrest and fasten to backrest hinge bolt with plastic washer and retainer.
15 Screw in screws on gear (8) inside and outside.
Tightening torque: 35 Nm.
Observe installation note.
16 Hook in control cable (2) on backrest lock (4).
17 Adjust backrest lock by screwing in completely both gear spindles with flexible drive shaft by hand all the way up against stop.
18 Check backrest lock, both locks should lock simultaneously and completely.
19 If necessary correct adjustment of the backrest lock by slightly turning the gear drive shaft.
20 The two control cables (2 and 3) of the backrest locking system must be adjusted to a play of 0-1 mm.
21 Install toothed belt and tension by shifting motor (M25m5) upward and tighten screws.
22 Adjust tension of toothed belt to play of approx. 3 - 7 mm when force of approx. 30 N is applied by hand.
23 Install flexible drive shaft, do not change the adjustment of the gear drive shaft set previously.
24 Engage backrest lock and check complete locking system by electrically checking the microswitches on the left and right (see Diagnosis Manual, Body, Volume 1, Section 4.1, Model R 129).
Connect measuring instrument to plug board X55/3 and check both microswitches individually.
25 Screw on retainer (7), route wire and fasten with cable straps.
Continue to reinstall in opposite order.
Outer side of seat
26 Disconnect connector S52/1x1 and expose wire to microswitch S52/1.
27 Unscrew bracket and remove flexible drive shaft for backrest adjusting gear.
28 Unscrew screws on backrest adjusting gear inside and outside.
Observe installation note.
Tightening torque: 35 Nm.
29 Remove retainer on backrest hinge bolt, unlock front seat backrest and tilt forward.
30 Unscrew bolt on backrest hinge until backrest lock (5) and adjusting gear can be pulled down slightly. Unhook control cable (3).
31 Remove backrest lock downwards out of backrest strut.
32 Remove clamping pin (diameter 3 mm and length 37 mm).
33 Unscrew gear spindle on backrest lock (5) and remove gear.
34 Screw gear spindle into backrest lock (5) until clamping pin can just be knocked in.
35 Install clamping pin (total length 37 mm).
36 Insert backrest lock (5) and gear (9) from below into backrest strut while hooking in control cable and installing backrest hinge bolt.
37 Install retainer on backrest hinge bolt.
38 Screw in bolt on backrest gear inside and outside while attaching retaining cable to inner screw of backrest gear so that it can still move.
Tightening torque: 35 Nm.
39 Continue to reinstall in opposite order. Before installing flexible drive shaft check adjustment and function of backrest lock (see backrest lock inside of seat, items 17-23).