Seats - Backrest Motion Excessive
89mercedes01TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS
DATE: February 1989
REF. NO. MBNA 91/17
SUBJECT: EXCESSIVE MOTION OF SEAT/BACKREST MODEL 107
The play in the seat track guide rail and the backrest adjustment bracket can sometimes be excessive. The source can be looseness at the seat track, the backrest mounting mechanism and/or the seat hinge and reclining mechanism.
In case of customer complaints, the procedures outlined in the enclosed Work Instructions No.236 should be followed to correct the problem.
Work Instructions
Group: 91
Date: February 1989 Number: 236
SUBJECT: EXCESSIVE MOTIOIN OF SEAT/BACKREST MODEL 107
Before starting to work, the exact source of the excessive motion has to be determined. It can be looseness at the seat track, the backrest mounting mechanism, and/or the seat hinge and reclining mechanism.
FIGURE 1:
Note: Excessive motion is, if dimension "A" is greater than 35 mm when moving the backrest in direction A, applied with 50N (approx. 11 lbs.) force. A motion of 35 mm or less is considered normal movement (Figure 1).
FIGURE 2:
1. Eliminating Play Between seat and Mounting Rail
1.1 To eliminate play between seat and mounting rail (arrow), the seat should be removed (job no. 91-100) (Figure 2).
FIGURE 3:
1.2 Remove both seat mounting rails by sliding them towards the rear (arrow) while holding the adjustment handle up (Figure 3).
FIGURE 4:
1.3 Install four black lower sliders 107 919 07 24, so that the longer side (arrow) points to the center of the seat (Figure 4).
FIGURE 5:
1.4 Remove white upper sliders and
check if rubber spacers 001 987 09 33 are installed. If not, insert rubber spacers (arrow) into the sliders (Figure 5).
1.5 Install white sliders on top of runners.
Note: The mounting rails must slide freely by hand, otherwise seat adjustment will be difficult.
1.6 Coat pivot surfaces of latch plates and inside of rails with MBpaste 001 989 14 51 before installing seat.
2. Eliminating Play at Backrest Mounting Mechanism
2.1 Fold backrest forward.
2.2 Replace the cross-hole nut if it shows signs of wear at its point of contact with the backrest mounting mechanism.
2.3 To adjust the bearing bolt use pin spanner 180 589 01 05 00 and loosen cross-hole nut.
FIGURE 8:
2.4 Adjust bearing bolt (3) to dimension "a" approximately 2 mm, in such fashion that the backrest mounting bracket neither chatters nor contacts the frame tunnel (Figure 8).
2.5 Lock bearing bolt with cross hole nut. Ensure that the contact surface between the cross-hole nut and the backrest mounting mechanism is maximized within the restraints listed in step 2.4 (Figure 8).
If the adjustment does not resolve the problem, replace bearing bolt (3). Repeat the adjustment.
FIGURE 9:
3. Eliminating Play at Seat Hinge/ Reclining Mechanism
3.1 If the play is determined to be in either gearing or shaft of the reclining mechanism, the complete backrest reclining mechanism must be replaced.
Special Tool Information
Tool Name Tool Number Group/Category
Pin spanner 180 589 01 05 00 91/C
Parts Information
Part Name Part Number
Seat rail, left seat left side 107 910 41 27
right side 107 910 43 27
Seat rail, right seat left side 107 910 44 27
right side 107 910 42 27
Slider, black 4 required 107 919 07 24
Slider, white 4 required 107 919 04 24
Rubber spacer 4 required 001 987 09 33
Cross-hole nut 107 990 00 56
Bearing bolt 107 918 00 15
Seat hinge/reclining mechanism left side 107 910 00 85
right side 001 910 11 86
MB-Paste 001 989 14 51
In Case of Warranty
Time Allowance
02-9139 Free-play between seat tracks and pin, Check/Reduce 0.1 hr. | 10
(seat removed)
02-9140 Free-play in seat tracks, Adjust 0.3 hr. | 10
(seat removed)
02-9141 Free-play in Backrest, Eliminate 0.3 hr. | 10
(seat removed)
91-0300 Front Seat - left, R & R 0.8 hr. | 10
91-0301 Front Seat - right, R & R 0.8 hr. | 10
91-0302 Front Seats - both, R & R 1.3 hr. | 10
Damage Code
91021 16 Seat guide rail, front seat, binding
17 Seat guide rail, front seat, excessive play
36 Seat guide rail, front seat, noisy
91023 16 Reclining mechanism, front seat, binding
17 Reclining mechanism, front seat, excessive play
36 Reclining mechanism, front seat, noisy