A) Replace carbon brushes.
Unscrew bolts.

Remove rotor.
Note when fitting: Diode support must be fitted in upper half.
Place corrugated disc in front of grooved bearing.
Check collecting rings.

Remove diode support.
Pull off plug for connecting cable.
Unscrew fastening bolts for carbon brush support.

Remove used carbon brushes and solder on new ones.
Note when fitting: Do not allow rosin-core solder to flow
onto the copper-stranded wire.

Push up carbon brushes and secure.
Assemble alternator.
Press carbon brushes onto collecting rings.

B) Replace grooved bearing
Lock cooling fan disc and remove.
Lift out disc spring.

Remove spacer ring (1).
Force out rotor (2).
Unscrew support plate (3).
Force grooved bearing (4) out of bearing cage (5).
Note when fitting: Coat grooved bearing with Ft 1 v 34
grease.
Make sure that the open end of the bearing faces towards the rotor.
Push contact ring (6) over wire safety catch (7).

Pull grooved bearing off rotor.
Note when fitting: Always use C 3 bearings only.
Coat grooved bearing with Ft 1 v 34 grease.
Make sure that the open end of the bearing faces towards
the housing.
Fit corrugated ring into housing before grooved bearing.

C) Plus diodes
Unfasten diode support.
Solder cables loose.

a) Applying not more than 24 volts, check diodes.
b) When + contact is placed on housing, the inspection lamp
must not go on.
Always replace all three diodes with diode suort at the same time.

D) Exciter diodes
Remove rotor.
Solder plus diodes, minus diodes and stator cable loose.
Remove diode support.

a) Applying not more than 24 volts, check diodes.
b) When + contact is placed on plug connection, inspection
lamp (P) must not go on.
Note when fitting: Always replace all three diodes
together with diode support.

E) Minus diodes
Solder stator cable and minus diodes loose.
Pull off flat plug.
Remove diode support.

Take out stator.
a) Applying not more than 24 volts, check diodes.
b) When + contact is placed on housing, the inspection lamp
must go on.
c) Coat diodes with silicone oil OL 63 v 2 and force them into
a sleeve with an inner dia of 17 mm (0.929"), using press tool
EFLJ 57/0.

F) Remove stator winding and check
Remove rotor.
Solder stator cable off diode support.
Take out stator.
a) Check stator winding for earth short circuit by applying
40 volt alternating current.

b) Check resistance between phase outputs:
0.26 Ohms + 10%.

G) Check pole rotor with jaw arrangement
Remove pole rotor with jaw arrangement and check for
earth short circuit by applying 40 volt alternating current.
(Check carried out with EFAW 84 tester.)

Check exciter winding (using Ohm meter).
14-volt unit / 4.0 Ohms + 10%.

Use EFAW 75 or GDF 85 R 3 tailstock backrest to overwind
the collecting rings.
Note: Minimum diameter of collecting rings 31.5 mm
(1.2402").

After overwinding collecting rings, check smoothness of
rotation. Max. permissible unbalance: 0.03 mm (001181").