Chevrolet 70 Series 1970, Service Manual

Page: 91 / 841

CAB AND BODY MOUNTINGS 1-60
VIEW A-LEFT MOUNTING VIEW B—RIGHT MOUNTING
(AIL STEEL TILT MODELS) (70 STEEL TILT MODELS)
Figure 34—Cab Torsion Bar Stop Brackets Installed
fra m e b ra ck et. Rem ove a rm fro m b a r and b ra ck et.
5. Loosen cap sc re w which clam ps cab rig h t
mounting b ra ck et to rig h t end of to rsio n b a r.
6. Slide to rsio n b a r from cab rig h t fra m e
b ra ck et, then slid e b a r in opposite d irectio n fro m
cab left support.
CAUTION: DO NOT hammer on end of bar.
INSTALLATION
1. B efore re p lacem en t of to rsio n b a r, inspect
fra m e b ra c k e ts (castings) and cab supp o rts (c a st­
ings) fo r c ra c k s. DO NOT WELD OR BRAZE
BRACKETS. If cracked, rep lace.
2. P re lu b ric a te left fram e b rack et opening and
rig h t fram e b ra c k e t. Slide hex end of to rsio n b a r
into left fra m e b ra c k e t, then in s e rt opposite end
into cab rig h t support.
3. In stall to rs io n b a r anchor le v e r o v er end of
b a r and into fra m e b ra ck et.
NOTE: L ev er should be located on b a r so that
opposite end of anchor le v e r is lo cated n e a r cen ter
of s e r ra tio n s on cab b ra ck et (fig. 33).
4. In sta ll cab stop b ra c k e ts (if p rev iously r e ­
moved) to to rsio n b a r cab and fram e b ra c k e ts a s
shown in fig u re 34. Torque attaching bolts to 35 to
50 foot-pounds. Make s u re stop b ra c k e ts a r e in­
s ta lle d a s shown.
5. In s ta ll to rsio n b a r rig h t fram e b ra c k e t cap
and cab left support cap with two bolts and w ash­
e r s . Torque b olts to 50-60 foot-pounds.
6. Tighten bolt which clam ps cab rig h t mount­
ing b ra c k e t to end of to rsio n b a r (fig. 34) to 65-75
foot-pounds on s e r ie s 70 o r 100-110 foot-pounds
on s e r ie s 90 tilt cab models.
7. L ubricate a ll cab tilt lubricatio n fittings
w ith lu b rican t specified in LUBRICATION (SEC. 0).
8. R aise and low er cab to check operatio n . If
cab r i s e s too fa st fro m operating position o r if
co n sid erab le effort is re q u ire d to ra is e cab, m ake
to rsio n b a r tension adjustm ent a s d irec ted la te r.
TORSION BAR TENSION
ADJUSTMENT
1. T ilt cab fo rw ard to an angle w hereby the
to rsio n a l load is re m o v e d fro m to rs io n b a r. Usually
the b a r w ill becom e unloaded when cab i s tilted
45 to 50 d eg rees. T his unloaded angle position
may v ary slightly on different v eh icles.
IMPORTANT: B efore continuing, check tigh t­
n ess of sc re w which clam ps cab rig h t mounting
b ra ck et to to rsio n b a r . Tighten screw firm ly ONLY
when to rsio n b a r is unloaded - cab tilte d p a r t way.
If sc re w is loose, cab b ra c k e t may fr a c tu re when
to rsio n b a r is loaded.
2. SAFELY support cab at angle a t which to r ­
sion b a r becom es unloaded. An ov erhead hoist is
recom m ended fo r supporting cab in th is position
a s it w ill allow cab to tilt slightly fo re o r aft to
fa c ilita te alignm ent of to rsio n b a r anchor le v e r to
cab fra m e b ra ck et.
3. Loosen nut on b olt which attach es the anchor
le v e r and s e r r a te d s p a c e r block to the cab fra m e
b ra ck et (fig. 33). Loosen nut only enough fo r s p a c e r
to c le a r s e rra tio n s .
4. By tiltin g cab slightly fo re and aft, the
sm a ll s e r r a te d s p a c e r block can be re lo c a te d to
new re la te d s e r ra tio n s on cab fra m e b ra c k e t a s
d esire d .
5. Tighten anchor bolt nut to 100-110 ft.-lb s .
6. Check cab tiltin g action. If n e c e ss a ry , r e ­
p ositio n anchor point of to rs io n b a r anchor le v e r
a s d irec ted above.
NOTE: If adjustm en t is such th at cab r is e s
rapidly to fu ll-tilt p osition , dam age to cab check
link could o cc u r and a lso upon low ering of the cab
to o perating p osition , con sid erab le effort may be
re q u ire d .
IMPORTANT: F in al check tig h tn e ss of anchor
le v e r bolt nut.
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL