Jeep UNIVERSAL CJ-2A - Page 211

N
REAR AXLE
N -2 1 B. T est On e
F or P owr- Lok Uni ts wi th Di shed P lates.
a. Place the tr ansmission in ne ut r al.
b. Raise one wheel off the floor an d place a block
in f ront and at the rear of the oppo si te wheel.
c. Apply a torque wrench to the axle shaft nut of
the elevated wheel.
d. Turn wheel with torque wrench. Disregard
breakaway to rqu e and observe torque req ui red to
continuously turn wh ee l sm oo thly. To r que sh ould
read 40 lb -ft. 15,53 kg -m.) or more.
c. Dis c type differentials that do not pass th is test
should be ove rhaul ed as outlined in P ar . N -19:
cone t ype should be rep l aced .
N-21C. T es t Two
For Any Powr - Lok Un i t.
a. Pla ce vehicle on smooth level floor.
b . Pla ce transm ission in neutr al.
c. Plac e a roll er type floor ja ck under one wheel
of
the axle to be t ested a nd rais e that wheel off
the Ao or.
d. Ti g ht en brake shoe on the rais ed wheel until
it can barely be moved when th e wheel is grasped
with both hands and an atte mp t is made to turn
it forward or backwards.
e. Next, start engine and shi ft to low gear holding
the clutch pedal down. Wi th eng in e at idle or just
above, engage the clutch easily, avoiding su dden
engagement or jerk. If the P ow r-L ok is operating
pr operly, t he veh icle should move forward, causing
the j ack to roll on the floor.
f. Dis c type differentials that do not pass this test
sh ould be over haul ed as outl in ed in Par. N-1 9:
cone type should be replaced.
N-21 D. Po w r- Lok Ch att er
a. Differ ential chatter is usua lly cau s ed by us e of
the wro ng lubri cant in the a x le differential. To
eliminate t he cha tt er, first drai n th e ax le housin g
thoroughly of th e o ld lubri ca nt . It is necessar y to
rotat e the wheels of th e vehicle (by ha nd only), to
allow
the lubri cant in the Powr -L ok uni t itsel f to
drain. Flush the differential, us ing a li ght engine
oil as the flushing age n t. Do not use solvent.
b. R eplace th e dr ain plug. Refill with the correct
amount of jeep Powr-Lok Differential Oil, P art
No. 94557.
c . In the event the above procedure ts not effecti ve
after 200 miles of operation, overha ul disc type
differentials, r eplace cone type.
N- 21 E. Po wr-Lok B ac kla sh
Exc essive lost motion, or backlash 111 the vehicle
dr iv e line, might be the r es u lt of excessive bac klas h
in th e t r ansm issi on, propeller sh aft sp line, univers al
jo i nt , ring gear a nd pinion, t he axle shaft spline , or
the differe ntial.
T he lost motion in the differential can be measure d
as follows:
a. j ack up one rear wheel.
b.
Pu t the transmission in gear .
c. M easure the travel of the jacked-up wheel on
a 1 0" radius from t he wheel ce n ter. This total
210
movement should n ot exceed 1 Yt " in a new uni t.
In o rd er to restr i ct the b ac kla sh to the axle onl y,
make sure that the axle and yoke of the pr opeller
sh
aft does not move d ur in g the ch ec k.
d . If all causes of back l ash me nti on ed above h ave
been eli minated, with the excep t ion of the di f-
ferential and different i al backlash exc ee ds th at
given in subparagraph c, ove rh aul the dis c type
diffe re ntial or re place the co ne type .
N-22. Ve hicl e Vibrations
• M odel DJ -3 A
See also Se rvic e Di ag nosis in the Clutc h a nd B ody
Secti on for o th er po ss i ble causes.
In som e inst ances, a secondary vi brat i on or c hatt er
will appear simu l taneously wi th the one de scri bed
under TROUBLE SHOOTI N G at the end of the
Clut ch Section. If th is v i brat i on is e xp er i enced
after the clu t ch disc has been replaced as desc rib ed
there, proceed as follows to attempt co rr ec ti on.
a. Drive the vehicle fo r approximately 20 miles
13 2 km.j to heat th e rear axle. B efore the ax le
can cool, raise the vehicle on a lift or jack up the
vehicle so that both r ea r wheels are off the ground
and install axle stands for safety.
b. Di sconnect the propeller shaft at the rear
universal joint and slowly turn the pinion shaf t
by turning the companion flange. If the pini on
shaft docs not turn freely and the mot i on does not
feel perfectly smooth, the preload on the pinion
bea r ings is at fault. Th ere is ei ther an insufficient
shim pack under the front pinion bearing or the
front pinion bearing cup is cocked . For correcting
e ith er condition, it will be necessary to remove
th e rear axle from the vehicle.
c. To check th e front pinion bearing cup for posi-
tive seating in the h ou sin g, insert a .0015" 10,0038
em.] feeler gauge or piece of shim stock between
th e bo tt om of the cu p and the s eat in the housing.
If th e cup is squ arely seated, it will not be poss i bl e
to ins ert the feel er at a ny point. P inion bearing
cones and c up s sho uld be closely exam i ned and
r eplaced if streaking, brinelling, or other damag e
is
evident.
d. If exam in ation dtscloses that th e front bea r ing
cup is squarely seated in the housing, check the
pinion bearing preload. Th e pinion shaft shoul d
h
ave no end play and should turn wi th a slight
dra g (without grease seal inst a lled ) after the com-
panion flange has been installed and secur ely
tightened. Usually. the ad diti on of a . 003" [0,076
em.] shim to the shim pack under the front pinion
oearing bnngs the desired r esult.
N-22A. Re ar Wh eel No i se
Lo oseness of the rear axle shaft nut on semi -
fl oating rear axles may produce a clicking or
creaking noise. Thi s noise can usually be stopped
by torquing the nut 1 SO to 175 lb-ft. 120,7 a 24,2
kg -m.). If the co nditi on has co n ti nu ed for some
time, slight w ear may have res u lted allowi ng the
noise to pe rsist. In this case, coat the hu b, k ey, and
key-way with wh ite lead and to rqu e t he nu t as
specified. If th e no i se pers is ts af te r t his treatm e nt ,
replace t he worn pa r ts.