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19 - 14
STEERING
•
BALL NUT
CENTER GROOVE
Fig. 17 Pitman Shaft & Bali Nut Engagement
CAUTION: Ensure that the ball nut is installed with
the wide/deep side of the ball nut teeth facing to-
ward the cover opening.
(6) I n s t a l l t h e wormshaft bearing adjustment cap
i n t h e housing and t i g h t e n i t only enough to remove
the wormshaft "end-play".
(7) I n s t a l l t h e l o c k n u t on the wormshaft bearing
adjustment cap b u t do n o t t i g h t e n i t a t t h i s t i m e .
(8) Pack t h e steering gear housing w i t h as m u c h
chassis l u b r i c a n t as possible.
T o b e a b l e t o p a c k t h e m a x i m u m a m o u n t o f l u -
b r i c a n t i n t o t h e h o u s i n g , t h e b a l l n u t m u s t b e
m o v e d b a c k a n d f o r t h f o r b e t t e r access t o t h e
h o u s i n g i n t e r i o r . R o t a t e t h e w o r m s h a f t i n o n e
d i r e c t i o n u n t i l t h e b a l l n u t ceases. P a c k t h e u n -
o b s t r u c t e d e n d o f t h e h o u s i n g f u l l o f l u b r i c a n t ,
r o t a t e t h e s h a f t i n t h e o p p o s i t e d i r e c t i o n a n d r e -
p e a t t h e p a c k i n g p r o c e d u r e .
(9) Place t h e b a l l n u t (Fig. 17) i n t h e centered po-
sition (i.e., rotate t h e wormshaft from "stop-to-stop"
and count t h e t o t a l number rotations, and then ro-
tate wormshaft i n t h e reverse direction 1/2 of the to-
t a l number of rotations to center the b a l l n u t ) .
(10) Lubricate t h e p i t m a n shaft w i t h chassis l u b r i -
cant and insert i t i n t h e steering gear housing. E n -
gage the center tooth on t h e shaft w i t h the center
groove on the b a l l n u t .
(11) Apply chassis l u b r i c a n t to t h e replacement
housing cover gasket a n d position i t so t h a t i t sur-
rounds the housing cover opening.
(12) Place t h e shim(s) on t h e adjustment screw and
thread the screw into t h e cover to a depth of 2 to 3
threads.
(13) Slide t h e head of t h e adjustment screw i n t o
t h e p i t m a n shaft T-slot and, w i t h t h e cover i n place,
rotate t h e screw counterclockwise t o t h r e a d i t i n t o
t h e cover. Rotate t h e screw u n t i l t h e cover almost
comes i n contact w i t h the gasket.
(14) I n s t a l l t h e cover r e t a i n i n g bolts a n d "finger-
t i g h t e n " t h e m only. Continue t i g h t e n i n g t h e adjust-
m e n t screw counterclockwise u n t i l t h e cover is t i g h t
against t h e gasket and t h e n loosen t h e screw 1/2 r o -
t a t i o n .
(15) T i g h t e n t h e cover bolts w i t h 6 1 N*m (45 ft-lbs)
torque.
CAUTION: A protective wrap must be used to en-
close the shaft threads/splines during the shaft seal
installation. If the shaft seals are installed over ex-
posed shaft splines or threads, the seal lips could
be cut or distorted and result in leakage after as-
sembly.
(16) I n s t a l l t h e p i t m a n shaft a n d wormshaft seals
according to t h e following procedure:
• w r a p t h e p i t m a n shaft threads/splines w i t h 0 . 1 -
m m (0.005-in) t h i c k shimstock (or a single layer o f
the t h i n n e s t plastic tape available) to protect t h e re-
placement seals d u r i n g i n s t a l l a t i o n ;
• l u b r i c a t e t h e lips o f t h e replacement seals w i t h
chassis l u b r i c a n t ;
• slide t h e seals over the shimstock/tape a n d shaft
and i n t o t h e steering gear housing recess;
• remove t h e shimstock/tape from t h e shaft;
• complete t h e seal i n s t a l l a t i o n by t a p p i n g t h e seals
i n t o t h e recesses w i t h a s m a l l plastic mallet; a n d
• ensure t h a t each seal is f u l l y "seated" i n the hous-
i n g recess.
(17) Rotate t h e wormshaft and observe t h e steering
gear operation. W i t h the adjustment screw and t h e
cap loose, t h e wormshaft should rotate freely and not
" b i n d " i n either direction of r o t a t i o n . I f the steering
gear " b i n d s " , repair as necessary.
(18) Inspect for l u b r i c a n t leakage from t h e shaft
seals. I f there is a leak at either seal, replace t h e de-
fective seal(s).
ADJUSTMENTS ON-BENCH
A r e c i r c u l a t i n g - b a l l type steering gear requires t w o
adjustments after assembly:
• w o r m s h a f t bearing "preload" torque, and
• p i t m a n (sector) shaft overcenter drag torque.
CAUTION: Adjust the steering gear in the following
order only. Always adjust the wormshaft bearing
"preload" torque first, and then adjust the pitman
shaft overcenter drag torque last. Failure to do so
could result in damage to the gear or improper
steering response.
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