SERVICE MANUAL
renewed, bearing preload should be
checked and adjusted as outlined in
paragraph 159.
159.
CARRIER BEARING PRE·
LOAD.
The differential carrier bearing
preload is adjusted by installing correct
thickness spacer shield (3-Fig. 155), or
shim depending on differential type,
under right-hand carrier bearing cup
(4).
The recommended method of checking
the preload adjustment is by use of
Massey-Ferguson special tool
<MFN
245UK). If tool is not available, an alter
nate procedure (although not as ac
curate) can be used as follows:
This adjustment procedure should be
performed with bevel drive pinion gear
(22) removed
to
prevent interference with
movement of differential. Install dif
ferential assembly and left-hand axle
housing, or carrier bearing housing (19),
depending on differential type. Install a
1.27
mm
(0.050 inch) spacer shield, or
several shims, and bearing cup into
right-hand axle housing or carrier hous
ing (1).
NOTE: A spacer shield thickness change
Is likely using this procedure. When shield
is removed
it
Is usually distorted beyond
reuse.
Position axle housing or carrier hous
ing (without gasket or
"0"
ring) onto
dif.
ferential housing and install three or
four equally spaced retaining cap screws.
Tighten cap screws evenly until end play
of differential is just removed. Rotate dif
ferential several turns to make certain
that bearings are properly seated. Use
a feeler gage
to
measure gap between ax
le housing and differential housing at
several different locations. Preload will
be correct when measured gap is 0.43-
0.55 mm (0.017-0.022 inch) on models
with drum brake axles, or 0.25-0.38 mm
(0.010-0.015 inch) on models with disc
brake axles. Remove axle housing or car
rier housing and change spacer or shim
thickness as necessary.
Fig. 156-VIew of differential lock pedal (12),
clevis (11) and locknut (9) used on Orchard
models and MF250 models. Refer to text for
adjustment.
DIFFERENTIAL LOCK
All Models So Equipped
160.
OPERATION.
When the dif
ferential lock foot pedal is depressed, the
axle half of coupler is forced inward to
contact the differential case half of the
coupler. If slippage is occurring at one
wheel, depressing the pedal will cause
the coupler dogs to lock the differential
case to the right axle. The differential
and both drive wheels then rotate
together as a unit.
As
soon as contact is
made by the coupler dogs, the pressure
wlll keep the differential lock engaged
and foot pedal may be released. When
ground traction on both drive wheels
again becomes equal, coupler dog con
tact pressure will be relieved and the
coupler will automatically disengage.
161.
ADJUSTMENT.
On all except
Orchard models and MF250 models, dif
ferential Jock coupler should be fully
engaged when pedal (16-Fig. 158) clears
tra
c
t
o
r step plate
by
12
mm
(1/2
inch).
If
adjustment is required, loosen clamp
screw (17) and reposition pedal (16) on
actuating shaft (11). Retighten clamp
screw when adjustment is complete. On
Fig. 157-Exploded view of
differential lock actuetlng
mechanism and assoclaterl
parts used on models with
disc brakes.
I.
Coupling
half
2.
Coupling half
3. Shin. fork
4. "0.,
ring
5.
Actuating thaJ\
6. Wuher
7. Spring
8.
Snap r1ng
9.
L«knut
10. Boot
11.
Cle._...
12.
Pedal
13. Pivot pin
Fig. 158-Exploded view of
differential lock mechanism
typical of all models except
Orchard models and MF250
models.
I.
Axle housing
(R. RJ
2.
Fork
bracket
3.
Sh01t
4. Actuating fork
6.
Pivot bolt
6. Oil seal
7. Coupling
8.
Spacer sh1eld
9.
Shim
10 Bearing
cup
l l Actuating cam
12
Pin
13
Bushing
14 Bracket
15
Return
6prmg
1
6 P
e
da
l
17. Clamp bolt
18.
Bushing
Paragraphs
1 59-1 62
Orchard models and MF250 models,
pedal (12-Fig. 156) shoul
d
be against
stop (S) when released. If not against
stop, loosen locknut (9) and turn clevis
(11) until pedal arm just contacts stop
(S). Tighten locknut (9) after acljustment
is complete.
162.
REMOVE AND REINSTALL.
'Ib
remove the differential lock coupler
halves (6 and 8-Fig. 155), first drain
transmission and hydraulic reservoir,
block up under diffet·ential housing and
remove right fender and rear tire and
wheel assembly. Remove right lower
hitch link and disconnect right brake
linkage. Support rear axle housing
assembly in a hoist and remove retain
ing stud nuts, then slide right rear axle
and housing as a unit away from dif·
ferential housing.
Remove bearing cone (7) from coupling
half (8). Remove the differential case re
taining cap screws and lift off t.he
cou
pling (8). Wben installing, tighten
differential case cap screws
to
a
torque
of
N
·
m
(80
ft.-lbs.).
'Ib
remove axle half of coupler on
models without planetary final drive,
upbolt rear axle outer bearing retainer
from axle housing {1-Fig. 158) and
65