Oil Pan: Service and Repair
Removal
1 Drain engine oil.
2 On model 116.120, remove engine hood.
On model 123, move engine hood into 90° position and engage detent lever (arrow).
3 Remove intermediate member on air cleaner (arrow).
4 Unscrew fan cover and place over fan; loosen radiator.
Model 116.120
5 Remove longitudinal regulating shaft. For this purpose, pull out locking eye (arrow).
Model 123
On models 116.120 and 123. pull longitudinal regulating shaft out of rubber mount in forward direction and remove in rearward direction.
6 Unscrew holding clamp of oil dipstick guide tube on power steering pump mounting bracket.
7 Slacken V-belt of refrigerant compressor and remove.
Unscrew refrigerant compressor with carrier. For this purpose, unscrew screws (1-4) and loosen clamp (arrow) of air-oil cooler lines.
8 Unscrew both engine shock-absorbers on frame cross member or console for lower control arm.
9 Loosen exhaust lateral support on transmission.
10 Unscrew fastening screws of engine carrier on engine mount from below.
11 Unscrew oil cooler lines for automatic transmission, on transmission, on intermediate flange and on oil pan upper half.
12 Unscrew the 4 lower screws on intermediate flange (arrows).
13 Unscrew cover plate on intermediate flange.
14 Unscrew oil pan lower half and remove.
15 Knock-out oil dipstick guide tube as far as possible by means of knocking-out mandrel 9 mm dia. for valve guides.
Attention! The oil dipstick guide tube cannot yet be pulled out.
16 Pull off adaptor with strainer on oil pump (arrow).
17 Unscrew oil pan upper half.
18 Attach rope of engine hoist (Motordirigent) to suspension eye at front on cylinder head (arrow).
19 Lift engine as far as possible by means of engine hoist and a crane. For this purpose, on model 123, open rear clamp on air cleaner so that it will not abut against battery while lifting.
20 Pull out oil dipstick guide tube.
21 Pull oil pan in downward direction and remove in forward direction.
To remove oil pan, turn crankshaft with tool combination until oil pan upper half can be pulled past connecting rod or crankshaft webs.
22 Thoroughly clean parting surface on cylinder crankcase, on oil pan upper and lower half.
Installation
NOTE: If a new oil pan upper half is installed, insert oil return pipe and contoured gasket first.
Renew damaged or porous contour gaskets and O-rings.
When removing oil return pipe, push out contoured sealing ring from oil pan first.
23 Renew rear radial sealing ring in oil pan according to condition.
Insert new radial sealing ring into groove and work in with a lubricated hammer handle.
Dimension a = 1.0 mm
24 To obtain an overlap, cut off radial sealing ring 1 mm above parting surface, using self-made gauge.
25 Provide radial sealing ring with engine oil.
9 Oil return line from cyclonic oil separator
10 Oil return line from exhaust gas turbocharger
26 Coat parting surface of oil pan top uniformly with sealing compound, part no. 001 989 46 20. Use this type of sealing compound only.
27 Position oil pan upper half, while inserting oil dipstick guide pipe, oil return pipe from exhaust gas turbocharger and from cyclonic oil separator (on engines with EGR only).
28 Screw down oil pan upper half.
29 Knock-in oil dipstick guide tube up to flange by means of knocking-in tool.
30 Lower engine. Pay attention to installation position of shielding plates and guide engine shock- absorbers into bores on frame cross member.
31 Insert adaptor with strainer at oil pump.
32 Screw-on oil pan lower half with new gasket.
33 For further installation proceed vice versa.
34 Add engine oil.
35 Run engine and add gear oil.
36 Run engine warm and check for leaks.