Page 461 of 524

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
460 Vehicle Care
Steering, Suspension, and
Chassis Components
Visually inspect steering,
suspension, and chassis
components for damaged,
loose, or missing parts or signs
of wear at least once a year.
Inspect power steering for
proper attachment,
connections, binding, leaks,
cracks, chafing, etc.
Visually check constant
velocity joint boots and axle
seals for leaks.
Body Component
Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges,
and the steel fuel door hinges,
unless the components are
plastic. Applying silicone
grease on weatherstrips with
a clean cloth will make them
last longer, seal better, and
not stick or squeak.
Underbody Maintenance
Every six months, use plain
water to flush any corrosive
materials from the underbody.
Take care to thoroughly clean
any areas where mud and
other debris can collect.
Do not directly power wash
the transfer case and/or
front/rear axle output seals.
High pressure water can
overcome the seals and
contaminate the fluid.
Contaminated fluid will
decrease the life of the
transfer case and/or axles and
should be replaced.
Sheet Metal Damage
If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the
body repair shop applies
anti-corrosion material to
parts repaired or replaced to
restore corrosion protection.Original manufacturer
replacement parts will provide
the corrosion protection while
maintaining the vehicle
warranty.
Finish Damage
Quickly repair minor chips and
scratches with touch-up
materials available from your
dealer to avoid corrosion.
Larger areas of finish damage
can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting
Airborne pollutants can fall
upon and attack painted
vehicle surfaces causing
blotchy, ring-shaped
discolorations, and small,
irregular dark spots etched
into the paint surface. See
“Finish Care”
previously in this
section.
Page 471 of 524

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
470 Service and Maintenance
may also be needed if you
notice reduced airflow,
windows fogging up,
or odors. Your local GM
Service location can help you
determine when it is the
right time to replace your
filter.
Every 72 000 km (45,000 mi)
.Change rear axle fluid,
if equipped with limited slip
differential. Do not directly
power wash the transfer
case and/or front/rear axle
output seals. High pressure
water can overcome the
seals and contaminate the
transfer case fluid.
Contaminated fluid will
decrease the life of the
transfer case and/or axles
and should be replaced.
Every 96 000 km (60,000 mi)
.Replace spark plugs. Inspect
spark plug wires and/or
boots. Every 156 000 km
(97,500 mi)
.Change transfer case fluid,
if equipped with AWD. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High
pressure water can
overcome the seals and
contaminate the transfer
case fluid. Contaminated
fluid will decrease the life of
the transfer case and/or
axles and should be
replaced.
Every 161 000 km
(100,000 mi)
.Replace hood and/or body
lift support gas struts. Or
every 10 years, whichever
comes first. See Gas Strut(s)
0 402.
Every 240 000 km
(150,000 mi)
.Change rear axle fluid,
without limited slip
differential. Do not directly
power wash the transfer
case and/or front/rear axle output seals. High pressure
water can overcome the
seals and contaminate the
transfer case fluid.
Contaminated fluid will
decrease the life of the
transfer case and/or axles
and should be replaced.
.Change front axle fluid,
if equipped with AWD. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High
pressure water can
overcome the seals and
contaminate the transfer
case fluid. Contaminated
fluid will decrease the life of
the transfer case and/or
axles and should be
replaced.
.Drain and fill engine cooling
system. Or every six years,
whichever comes first. See
Cooling System
0386.
Page 474 of 524

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 473
Exterior Lights
.Visual inspection
Windshield and Wipers
.Visual inspection
Battery
.Battery visual inspection
.Battery test results
.Battery cables and
connections
Systems, Fluids, and
Visible Leak Inspection
.Engine oil
.Transmission
.Drive axle
.Transfer case
.Engine cooling system
.Power steering, if equipped
.Fuel system
.Windshield washer fluid
Tire Inspection
.Tire pressure, tread depth,
and wear
.Rotation, if applicable
.Alignment check, optional
.Reset tire pressure monitor
.Check tire sealant expiration
date, if equipped
.Check spare tire, if equipped
Brakes
.Check brake system
Visible and Functional
Inspections
.Seat belt components
.Exhaust system
.Accelerator pedal
.Passenger compartment air
filter, if equipped
.Engine air filter
.Hoses
.Belts
.Shocks and struts
.Steering components
.Axle boots or driveshaft and
u-joints
.Compartment lift struts,
if equipped
.Floor mats secured, no
interference with pedals
.Horn
.Ignition lock, if equipped
.Starter switch
.Evaporative control system
Lubricate
.Chassis components
Special Application
Services
.Severe Commercial Use
Vehicles Only: Lubricate
chassis components every
oil change.
.Have underbody flushing
service performed. See
"Underbody Maintenance" in
Exterior Care 0455.