Checking and reconditioning crankshaft

Data

Crankshaft journal dia. for mounting compensating weight

0.030

Permissible deviation of crankshaft journal prior to mounting compensating weight

from cyl. shape

0.005

from true¹)

0.030

Permissible deviation of crank pins and crankshaft bearing journals from true

0.0025

Permissible deviation of crank pin cyl. line from parallel

0.010

Permissible deviation of running surfaces of fitted bearing from parallel¹)

0.020

Permissible deviation of running surface of rear radial sealing ring from concentric true¹)

0.015

Permissible deviation of flywheel flange from axial true¹)

0.010

Permissible deviation of crankshaft bearing journal from concentric true¹)

journal II, VI

0.070

0.100

journal III, IV, V

Fillets on crankshafts and crank pins

2.5 to 3

03.2-318/1 F3

when new

74-84

Scleroscope hardness of crankshaft bearing journals and crank pins

boundary value

60²>

Permissible unbalance of crankshaft

15 cmg

1)    When mounting crankshaft on outer crankshaft bearing journal I and VII after one full turn.

2)    Boundary value should be available at min. 2/3 of journal circumference.

Impact hardness tester

000 589 20 21 00

Rivet support for riveting counterweight to crankshaft.

03.2-318/2 F3

Since December 1978, the crankshaft of engine 110

is provided with an additional weight.

Remove additional weight when machining first crank

pin.

After machining crank pin, rivet additional weight on

again. Then check crankshaft for runout, and balance

together with flywheel and balancing disc, also when

re-using the old additional weight.

The crankshaft with riveted-on additional weight may be used only together with a modified oil pump which is provided with a recess (arrow) on housing shaft.

When checking and reconditioning crankshafts, pro­ceed in sequence of the following diagram and perti­nent explanations.

For grinding crank pins, a difference of only one re­pair stage per crankshaft is permitted.

03.2-318/3 F3

03.2-318/4 F3

Clean crankshaft. Bearing journals should be free of oil and grease. Magnetize crankshaft and apply fluorescent powder (flux). A color penetration meth­od (insertion in bath or with spray can) can also be applied.

Aids: paint or fluorescent powder, cleaning agent, developer.

Test hardness with impact hardness tester (scleros-cope hardness).

Scleroscope hardness of 60 should be available at 2/3 of journal circumference.

Journals without hardened fillets can be hardened inductively or by flame hardening. Journals with hardened fillets (arrows) should be inductance-hardened on principle. If this is not possible, scrap crankshaft.

When hardening journals without hardened fillets, maintain distance A between runout of hardened surface and fillet (4—5 mm).

03.2-318/5 F2

For a good hardening job, test adjustment of hardening plant by metallographic grinding tests.

These tests can be made by testing scrapped crank­shafts.

Check hardening by etching surface of journal with a 2% alcoholic nitric acid (HNO₃).

No dark spots should show up at surface of journal. Non-hardened fillets will become dark.

The hardened fillets, on the other hand, should be as bright as surface of journal.

For comparison, perform an etching job on a metallo-graphically controlled journal.

Then, carefully wash off nitric acid by means of alcohol.

Crankshafts which are not immediately installed again should be lubricated with engine initial operation oil (SAE 30).

03.2-318/6 F2

1 Punch mark countersunk rivet 6 x 28 mm accurate­ly in center.

2 Drill into rivet heads with a 6.5 mm dia. drill and knock out.

3 Slip-on new or former, undamaged additional weight together with 4 countersunk rivets.

4 Introduce crankshaft.into a suitable steel tube (approx. 165 mm dia. x 420 mm long) and place self-made rivet support (2) underneath.

1   Steel tube 165 mm dia. x 420 mm long

2  Self-made rivet support

3  Snap die

03.2-318/7 F3

5   Rivet countersunk rivet by means of a hydraulic press. The additional weight should then rest fully against crankshaft cheek without leaving any inter­mediate space.

6   Then check crankshaft for runout of bearing journals and balance together with balancing disc and flywheel, even if the former additional weight is used again.

1  Crankshaft

2  Additional weight 1 TO 031 05 01

3  Countersunk rivet 6 x 28 mm DIN 661 MUSt 34

Series production of riv®tsd-on additions! weight starting December 1978

starting engine end no.

starting chassis end no.

110 992 -10-038

-12-062 390

116.020-112 253

923

–¹⁰–⁰¹²⁶⁶⁵ -12-015613

123.030-025 675 123.050-002 801

932

–¹⁰–⁰⁰⁹⁷⁴⁸ -12-002 556

116.020-112 253

110 984 “10-014 634 -12-051 160

123.033-050 600 123.053-013 292

110.984 “10-014 634 -12-051 160

123.093-001 229

110.985 -10-011 106 -12-052 660

116.024/025-131 270

110.986 -10-002 276 -12-005 142

107.022-006 288 107.042-005 285

03.2-318/8 F3