Removal & Installation of Rear Axle Center Assembly
Removal and installation of rear axle center piece
Vehicles with ASD(54/1)
Rear axle center piece (54, 54/1)
Exhaust system (120-121a)
Muffler guard plate (108)
Clamping nut on propeller shaft (110b)
Propeller shaft intermediate bearing (110a)
Propeller shaft (110)
Rear axle shafts (28)
Rear self-locking serrated bolts (57d)
Front self-locking Allen bolts (54c)
Speed sensors, ABS/ASR (L6, L6/3 and L6/4)
Rubber supports (54a, 54b, 57a, 57b)
Special tools
Note: The work sequence for removal and installation is identical for models 107 and 126, any deviations are indicated.
On vehicles with ASD the pressure must be released in the hydraulic unit. Check oil level, correct if required and bleed system.
Removal, installation
1. Drain oil from rear axle, fill (arrows).
Installation note: Pay attention to oil types and capacities, see data.
Arrangement, Model 126.02:
Arrangement, Model 126.03 /04:
2. Remove exhaust system beginning at inserted connection (arrows).
Vehicles with catalytic converter: Disconnect plug connector for 02 sensor. When installing assure that lines are positioned correctly.
3. Remove exhaust guard plate, install.
Installation note: Tightening torque for M8 hex. nuts and bolts: 25 Nm.
4. Loosen clamping nut on propeller shaft, tighten and screw propeller shaft intermediate bearing off at frame floor, screw on.
Installation note: Clamping nut 30-40 Nm, propeller shaft intermediate bearing 25 Nm. Torque wrench 001 589 66 21 00, open-end wrench 46 mm 126 589 00 01 00.
5. Disconnect propeller shaft at rear axle center piece, install.
Installation note: Renew self-locking hex. nuts. Tightening torque: M10 = 40 Nm, M12 = 60 Nm.
Note: On models 126.03/04 up to approx. beginning of 10/85 the three hex. head bolts for mounting the joint plate on the joint flange must be installed from the rear toward the front for reasons of space. The bolts can only be inserted when the joint flange is located at the same height as the point on the rear axle housing marked with an arrow.
6. Push propeller shaft toward front out of centering device. Previously loosen fitted sleeves from joint flange in radial direction with suitable punch.
Caution: Secure propeller shaft against falling with binding wire; for this purpose use two mounting screws of exhaust guard plate (arrows).
7. Screw out Allen bolt (L6a), screw in. Remove speed sensor (L6) from rear axle housing, install.
8. Cover magnetic blade on speed sensor and opening in rear axle housing.
Caution: Protect speed sensor against damage. Do not pull on line.
Installation note: Renew self-locking Allen bolt (L6a). Check 0-ring (L6b) for damage. Assure that no metal residues are present on magnetic blade of speed sensor. Check oil level and add oil up to height of fill opening. Tightening torque 8 Nm.
Vehicles with ASD
9. Screw off HS line on ring cylinder, screw on and clip out of holder, clip in. Plug connections with suitable rubber stoppers.
Installation note: Check line connection for leakage and good hose position. Bleed hydraulic system if required.
10. Screw off rear axle shafts at connection flanges, screw on.
Installation note: Renew self-locking serrated or Allen bolts. Tightening torque: M10 = 70 Nm, oil bolt head contact surface and thread, M12 = 125-145 Nm.
11. Press rear axle shafts together and fasten to rear springs with binding wire, unfasten.
12. Support rear axle center piece with jack or pit lift.
13. Screw off rear self-locking serrated screw on cover, screw on and remove together with rubber supports, install (arrow).
Installation note: Install rear upper and lower rubber support (57a, 57b) with sleeve (57c) and new self-locking serrated bolt (57d). Check rubber supports for damage, renew if required. Tightening torque: 110 Nm.
14. Loosen front self-locking Allen bolts, tighten.
Installation note: Check front rubber supports (54a, 54b) for damage, renew if required. Position rubber support on center piece and press upward against stop on rear axle carrier. Renew self-locking Allen bolts (54c), tightening torque: 60 Nm.
Vehicles with ASR
15. Carefully lower rear axle center piece until self-locking Allen bolts in speed sensors (L6/3, L614} can be reached to loosen or tighten, raise. Do not pull against lines for speed sensors.
L6/3 Speed sensor, left
L6/4 Speed sensor, right
L6/3b 0-ring
L6/4b 0-ring
Installation note: Renew 0-ring (L6/4b). Before installation assure that spacer (L6/4c) is seated properly. Moreover foreign bodies must not be present on the magnetic blade of the speed sensor. Renew self locking Allen bolts. Assure that lines are positioned correctly.
16. Lower rear axle center piece, or lift.
17. Install in opposite order.