SPRINGS, SHOCK ABSORBERS Figure 5 - Progressive Spring Assembly MAINTENANCE Lubrication For lubrication intervals, refer to Operator’s Manual.  For types of lubricants recommended, refer to LUBRICATION section CTS-4033. Retightening U-Bolt Nuts U-bolt  nuts  must  be  retightened  at  the  intervals  listed below. This applies to both new vehicles and to vehicles on which spring service has been performed. 1. The  U-bolt  nuts  must  be  retightened  after  the vehicle   has   operated   under   load   for   1   600 kilometers (1,000 miles) or six months, whichever occurs first. 2. Thereafter,   the   spring   U-bolt   nuts   should   be retightened    every    58,000    kilometers    (36,000 miles). CAUTION---WHEN CHECKING U-BOLTS TO DETERMINE IF LOOSENESS HAS OCCURRED, TORQUE VALUES OF 40% OF THE SPECIFICATIONS WOULD ASSURE JOINT INTEGRITY, PROVIDED THE U-BOLTS AND NUTS WERE IN LIKE-NEW CONDITION.        HOWEVER,    ALWAYS    TIGHTEN    TO ORIGINAL  SPECIFICATIONS.  RUSTY  JOINTS  MUST BE   DISASSEMBLED,   CLEANED   AND   LUBRICATED TO   ASSURE   A   LIKE-NEW   CONDITION   PRIOR   TO TIGHTENING. SERVICING Although   the   exact   servicing   procedures   are   different for  each  type  of  spring  assembly  and  application,  the basic procedures are similar.  The following is a general outline for servicing all spring assemblies. Removal 1. Place   floor   jack   under   truck   frame   and   raise truck sufficiently to relieve weight from spring  to be removed. 2. Remove shock absorbers where used. 3. Remove  U-bolts,  spring  bumper  and  retainer  or U-bolts seat. 4. Remove lubricators (not used on springs equipped with rubber bushings). 5. Remove    nuts    from    spring    shackle    pins    or bracket pins. 6. Slide spring off bracket pin and shackle pin. Disassembly 1. Clamp    spring    end    in    vise    and    remove    old bushing from spring eye. 2. Reposition spring in vise so that assembly will be clamped near center. 3. If  bolted-type   rebound   clips   are   used,   remove nuts,    bolts    and    spacers.    Where    clinch    type rebound  clips  are  used,  bend  tabs  of  clips  up, being  careful  not  to  break  them.  Heating  clips with torch will help avoid breakage. 4. Remove nut from spring center bolt. 5. Release vise to permit spring leaves to separate. Remove  spring  from  vise  and  separate  leaves from center bolt. Cleaning, Inspection and Repair 1. Wash all parts in cleaning solvent or use steam cleaning equipment to remove grease and scale. Use a wire brush to hasten dirt removal. Do    not    immerse    rubber    spring    bushings    in cleaning   solvent.      Use   a   non-petroleum   base type  rubber  lubricant  on  a  clean  cloth  to  wipe these parts clean. 2. Inspect    all    spring    leaves    for    breakage    and cracks.    Also  compare  arch  of  leaves  with  new leaves.  If leaves are flattened out, replace. 3. Spring  pins  must  be  replaced  if  they  are  worn, corroded or cracked. 4. Spring  eye  bushing  and  spring  shackle  bushing must also be replaced if defective. 5. Check   spring   brackets   for   cracks   or   for   wear around   mounting   bolt   or   rivet   holes.   Replace bracket if damaged. 6. Always use new center bolts at each overhaul. CTS-4168—Page 3