RAM CHASSIS CAB 2019 Owners Manual
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SERVICING AND MAINTENANCE 439
Automatic Transmission
Selection Of Lubricant 
It is important to use the proper transmission fluid to ensure
optimum  transmission  performance  and  life.  Use  only  the
manufacturer’s specified transmission fluid. Refer to “Fluids
And  Lubricants”  in  “Technical  Specifications”.  It  is
important  to  maintain  the  transmission  fluid  at  the  correct
level  using  the  recommended  fluid.  No  chemical  flushes
should be used in any transmission; only the approved lubri -
cant should be used. Special Additives 
The  manufacturer  strongly  recommends  against  using  any
special  additives  in  the  transmission.  Automatic  Transmis -
sion  Fluid  (ATF)  is  an  engineered  product  and  its  perfor -
mance  may  be  impaired  by  supplemental  additives.
Therefore,  do  not  add  any  fluid  additives  to  the  transmis -
sion.  The  only  exception  to  this  policy  is  the  use  of  special
dyes  for  diagnosing  fluid  leaks  in  six-speed  transmissions.
Avoid  using  transmission  sealers  as  they  may  adversely
affect seals.• Overfilling  the  brake  fluid  reservoir  can  result  in
spilling  brake  fluid  on  hot  engine  parts,  causing  the
brake  fluid  to  catch  fire.  Brake  fluid  can  also  damage
painted  and  vinyl  surfaces,  care  should  be  taken  to
avoid its contact with these surfaces.
• Do not allow petroleum based fluid to contaminate the
brake fluid. Brake seal components could be damaged,
causing  partial  or  complete  brake  failure.  This  could
result in a collision. WARNING!  (Continued) CAUTION!
Using a transmission fluid other than the manufacturer’s
recommended  fluid  may  cause  deterioration  in
transmission  shift  quality  and/or  torque  converter
shudder,  and  (for  six-speed  transmissions)  will  require
more  frequent  fluid  and  filter  changes.  Refer  to  “Fluids
And  Lubricants”  in  “Technical  Specifications”  for  fluid
specifications.
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440 SERVICING AND MAINTENANCE
Fluid Level Check — Eight-Speed Transmission
The  fluid  level  is  preset  at  the  factory  and  does  not  require
adjustment  under  normal  operating  conditions.  Routine
fluid  level  checks  are  not  required,  therefore  the  transmis -
sion  has  no  dipstick.  An  authorized  dealer  can  check  your
transmission fluid level using special service tools.
If you notice fluid leakage or transmission malfunction, visit
an  authorized  dealer  immediately  to  have  the  transmission
fluid level checked. Operating the vehicle with an improper
fluid level can cause severe transmission damage. Fluid Level Check — Six-Speed Transmission
It is best to check the fluid level when the transmission is at
normal  operating  temperature  (158-176°F  /  70-80°C).  This
normally occurs after at least 15 miles (25 km) of driving. At
normal  operating  temperature  the  fluid  cannot  be  held
comfortably between the fingertips. You can read  the  trans -
mission  sump  temperature  in  the  instrument  cluster  screen
(refer  to  “Instrument  Cluster  Display”  for  further  informa -
tion).
Use the following procedure to check the transmission fluid
level properly:
1. Monitor  the  transmission  temperature  using  the  instru -
ment cluster display, and operate the vehicle as required
to  reach  the  normal  operating  temperature.  If  the  trans -
mission is not functioning properly, or the vehicle cannot
be  driven,  see  the  NOTE  and  CAUTION  below  about
checking the fluid level at colder temperatures.
2. Park the vehicle on level ground.
3. Run  the  engine  at  normal  idle  speed  for  at  least  60
seconds, and leave the engine running for the rest of this
procedure.
4. Fully apply the parking brake, and press the brake pedal.CAUTION!
Do  not  use  chemical  flushes  in  your  transmission  as  the
chemicals  can  damage  your  transmission  components.
Such damage is not covered by the New Vehicle Limited
Warranty.
CAUTION!
If  a  transmission  fluid  leak  occurs,  visit  an  authorized
dealer  immediately.  Severe  transmission  damage  may
occur. An authorized dealer has the proper tools to adjust
the fluid level accurately. 
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SERVICING AND MAINTENANCE 441
5. Place  the  gear  selector  momentarily  into  each  gear  posi -
tion (allowing time for the transmission to fully engage in
each position), ending with the transmission in PARK.
6. Remove  the  dipstick,  wipe  it  clean  and  reinsert  it  until
seated.
7. Remove  the  dipstick  again  and  note  the  fluid  level  on
both sides. The fluid level reading is only valid if there is
a  solid  coating  of  oil  on  both  sides  of  the  dipstick.  Note
that  the  holes  in  the  dipstick  will  be  full  of  fluid  if  the
actual level is at or above the hole. The fluid level should
be  between  the  “HOT”  (upper)  reference  holes  on  the
dipstick  at  normal  operating  temperature.  If  the  fluid
level is  low, add fluid through the dipstick tube to bring
it to the proper level.  Do not overfill.  Use ONLY the spec -
ified fluid (see "Fluids And Lubricants" for fluid specifica -
tions).  After  adding  any  quantity  of  oil  through  the
dipstick tube, wait a minimum of two minutes for the oil
to fully drain into the transmission before rechecking the
fluid level.
NOTE:
If  it  is  necessary  to  check  the  transmission  below   the  oper -
ating temperature, the fluid level should be between the two
“COLD”  (lower)  holes  on  the  dipstick  with  the  fluid  at
60-70°F / 16-21°C. Only use the COLD region of the dipstick as a rough reference when setting the fluid level after a trans -
mission service or fluid change. Re-check the fluid level, and
adjust  as  required,  once  the  transmission  reaches  normal
operating temperature.
8. Reinsert the dipstick. Check for leaks. Release the parking
brake.
NOTE:
If  it  is  necessary  to  check  the  transmission  below  the  oper -
ating temperature, the fluid level should be between the two
COLD (lower) holes on the dipstick with the fluid at 68-86°F
/  20-30°C.  Only  use  the  COLD  region  of  the  dipstick  as  a
rough reference when setting the fluid level after a transmis -
sion  service  or  fluid  change.  Re-check  the  fluid  level,  and
adjust  as  required,  once  the  transmission  reaches  normal
operating temperature. CAUTION!
If the  fluid temperature is  below 50  °F  (10  °C) it may not
register  on  the  dipstick.  Do  not  add  fluid  until  the
temperature  is  elevated  enough  to  produce  an  accurate
reading.  Run  the  engine  at  idle,  in  PARK,  to  warm  the
fluid.
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442 SERVICING AND MAINTENANCE
Fluid And Filter Changes — Eight-Speed Transmission 
Under normal operating conditions, the fluid installed at the
factory will provide satisfactory lubrication for the life of the
vehicle.
Routine fluid  and filter changes are not  required.  However,
change the fluid and filter if the fluid becomes contaminated
(with  water,  etc.),  or  if  the  transmission  is  disassembled  for
any reason.
Fluid And Filter Changes — Six Speed Transmission
Refer to the “Maintenance Plan” for the proper maintenance
intervals.
In addition, change the fluid and filters if the fluid becomes
contaminated  (with  water,  etc.),  or  if  the  transmission  is
disassembled for any reason. Rear Axle And 4x4 Front Driving Axle Fluid Level    
For  models with  9.25 in  Front  Axles  and  11.5 in  Rear  Axles,
refer to “Fluids And Lubricants” in “Servicing And Mainte -
nance” for further information. For normal service, periodic
fluid  level  checks  are  not  required.  When  the  vehicle  is
serviced  for  other  reasons,  the  exterior  surfaces  of  the  axle
assembly should be inspected.
When  checking  the  fluid  level,  the  vehicle  should  be  in  a
level position. The fluid level at room temperature should be
as follows:
3500  Front  Axle:  ¼  in  ±  ¼  in  (6.4 mm  ±  6.4 mm)  below  the
bottom of the fill hole.
3500  Rear  Axle:  ¼  in  ±  ¼  in  (6.4 mm  ±  6.4 mm)  below  the
bottom of the fill hole.
4500/5500  Front  Axle:  ¼  in  +/-  ¼  in  (6.4 mm  ±  6.4 mm)
below the bottom of the fill hole.
4500/5500 Rear Axle: 1/8 in +/- 1/8 in (3.2 mm +/- 3.2 mm)
below the bottom of the fill hole.CAUTION!
If  the  fluid  temperature  is  below  50°F  (10°C)  it  may  not
register  on  the  dipstick.  Do  not  add  fluid  until  the
temperature  is  elevated  enough  to  produce  an  accurate
reading.  Run  the  engine  at  idle,  in  PARK,  to  warm  the
fluid. 
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SERVICING AND MAINTENANCE 443
Drain And Refill
On  4500/5500  vehicles,  remove  the  lower  bolt  to  drain  the
axle fluid.
4500/5500 Rear Axle Plugs
Refer to “Scheduled Servicing” in this chapter for the proper
maintenance intervals. Lubricant Selection    
Refer  to  “Fluids  And  Lubricants”  in  “Technical  Specifica -
tions” for further information.
NOTE:
The  presence  of  water  in  the  gear  lubricant  will  result  in
corrosion  and  possible  failure  of  differential  components.
Operation of the vehicle in water, as may be encountered in
some off-highway types of service, will require draining and
refilling the axle to avoid damage.
Limited-Slip  Differentials   DO  REQUIRE   limited  slip  oil
additive (friction modifiers).
NOTE:
Slight  noise  and  mild  shuddering  may  be  evident  while
turning a vehicle with limited slip differential on concrete or
dry  pavement.  These  conditions  should  be  considered
normal operation of the limited slip differential.1 — 4500/5500 Rear Axle Fluid Fill Plug
2 — 4500/5500 Rear Axle Fluid Drain Plug
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444 SERVICING AND MAINTENANCE
Transfer Case 
Selection Of Lubricant
Use  only  the  manufacturer's  recommended  fluid.  Refer  to
“Fluids  And  Lubricants”  in  “Technical  Specifications”  for
further information.
Fluid Level Check
This  fluid  level  can  be  checked  by  removing  the  filler  plug.
The fluid level should be to the bottom edge of the filler plug
hole with the vehicle in a level position.
Drain And Refill
Refer to the “Maintenance Plan” in this section for the proper
maintenance intervals. HOISTING 
A  conventional  floor  jack  may  be  used  at  the  jacking  loca -
tions.  Refer  to  the  graphics  that  show  jacking  locations.
However, a floor jack  or frame  hoist  must never be used on
any other parts of the underbody.
TIRES 
Tire Safety Information   
Tire  safety  information  will  cover  aspects  of  the  following
information:  Tire  Markings,  Tire  Identification  Numbers,
Tire  Terminology  and  Definitions,  Tire  Pressures,  and  Tire
Loading. CAUTION!
Never use a floor jack directly under the differential housing of
a loaded truck or damage to your vehicle may result.  
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SERVICING AND MAINTENANCE 445
Tire Markings 
Tire Markings NOTE:
• P (Passenger) — Metric tire sizing is based on U.S. design
standards.  P-Metric  tires  have  the  letter  “P”  molded  into
the  sidewall  preceding  the  size  designation.  Example:
P215/65R15 95H.
• European  —  Metric  tire  sizing  is  based  on  European
design standards. Tires designed to this standard have the
tire  size  molded  into  the  sidewall  beginning  with  the
section  width.  The  letter  "P"  is  absent  from  this  tire  size
designation. Example: 215/65R15 96H.
• LT  (Light  Truck)  —  Metric  tire  sizing  is  based  on  U.S.
design standards. The size designation for LT-Metric tires
is the same as for P-Metric tires except for the letters “LT”
that are molded into the sidewall preceding the size desig -
nation. Example: LT235/85R16.
• Temporary  spare  tires  are  designed  for  temporary  emer -
gency  use  only.  Temporary  high  pressure  compact  spare
tires  have  the  letter  “T”  or  “S”  molded  into  the  sidewall
preceding  the  size  designation.  Example:  T145/80D18
103M.
• High flotation tire sizing is based on U.S. design standards
and  it begins  with the tire  diameter  molded into the side -
wall. Example: 31x10.5 R15 LT.1 — U.S. DOT Safety 
Standards Code (TIN) 4 — Maximum Load
2 — Size Designation 5 — Maximum Pressure
3 — Service Description 6 — Treadwear, Traction 
and Temperature Grades 7 
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446 SERVICING AND MAINTENANCE
Tire Sizing Chart 
EXAMPLE:
Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT
P  = Passenger car tire size based on U.S. design standards, or
"....blank...."  = Passenger car tire based on European design standards, or
LT  = Light truck tire based on U.S. design standards, or
T or S  = Temporary spare tire or
31  = Overall diameter in inches (in)
215, 235, 145  = Section width in millimeters (mm)
65, 85, 80  = Aspect ratio in percent (%) 
• Ratio of section height to section width of tire, or
10.5  = Section width in inches (in)
R  = Construction code 
• "R" means radial construction, or
• "D" means diagonal or bias construction
15, 16, 18  = Rim diameter in inches (in)
Service Description:
95  = Load Index 
• A numerical code associated with the maximum load a tire can carry 
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SERVICING AND MAINTENANCE 447
H  = Speed Symbol 
• A symbol indicating the range of speeds at which a tire can carry a load corresponding to its load index under certain oper -
ating conditions
• The  maximum  speed  corresponding  to  the  speed  symbol  should  only  be  achieved under  specified  operating  conditions
(i.e., tire pressure, vehicle loading, road conditions, and posted speed limits)
Load Identification:
Absence of the following load identification symbols on the sidewall of the tire indicates a Standard Load (SL) tire:
• XL  = Extra load (or reinforced) tire, or
• LL  = Light load tire or
• C, D, E, F, G  = Load range associated with the maximum load a tire can carry at a specified pressure
Maximum Load  – Maximum load indicates the maximum load this tire is designed to carry
Maximum Pressure  – Maximum pressure indicates the maximum permissible cold tire inflation pressure for this tire EXAMPLE:
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448 SERVICING AND MAINTENANCE
Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire; however, the date code may only be on one side. Tires with white side -
walls  will  have  the full  TIN,  including the  date code,  located  on the  white  sidewall side of  the  tire. Look for the  TIN  on  the
outboard  side of  black  sidewall  tires  as  mounted  on  the vehicle. If  the  TIN  is  not  found  on the outboard side,  then you will
find it on the inboard side of the tire.
EXAMPLE:
DOT MA L9 ABCD 0301
DOT  = Department of Transportation 
• This symbol certifies that the tire is in compliance with the U.S. Department of Transportation tire safety standards and is
approved for highway use
MA  = Code representing the tire manufacturing location (two digits)
L9  = Code representing the tire size (two digits)
ABCD  = Code used by the tire manufacturer (one to four digits)
03  = Number representing the week in which the tire was manufactured (two digits) 
• 03 means the 3rd week
01  = Number representing the year in which the tire was manufactured (two digits) 
• 01 means the year 2001
• Prior to July 2000, tire manufacturers were only required to have one number to represent the year in which the tire was
manufactured. Example: 031 could represent the 3rd week of 1981 or 1991