Servicing
Definitions
Transmission Service
Drain the transmission pan
Change Filter
Removes approx. 1/3 of the transmission fluid
Adjust bands if applicable
Transmission Flush
Flushing machine is attached to the cooler lines and approx.
100% of the fluid is exchanged
Some of the flushing machines use an external pump
This may cause problems such as collapsed circuit screens
Some flushing machines use the transmission to pump the fluid
Do not add additives to the fresh transmission fluid
Procedures
Check Fluid Level
Even if you are changing fluid and filter check
the fluid, it may be low
Indicates a leak (find it)
If the level is high it indicates a leak (fluid added)
Check for aeration (bubbles in the fluid)
Indicates an air leak in the suction circuit or an
overfull transmission
Inspect the filter for damage
Inspect the filter seal
Checking Fluid Level
Engine must be running
Transmission in park
Dodge – Neutral
Pull stick out and wipe it clean
Stick it again
Read both sides of the stick
Believe the lower reading
Checking Fluid Level
Procedures
Talk to the customer
Why are they having the transmission serviced?
Routine maintenance?
Problems with the transmission?
If there are problems with the transmission, what are
they?
Inform them ahead of time that a service may not cure the
problem
A service can be a valuable diagnostic tool
See what is in the pan and the condition of the fluid
Has anyone put any additive into the fluid?
TransX
Lucus
BRAKE FLUID!!!
Test Drive?
Procedures
Remove the Pan
Leave a few bolts in and lower a corner
Inspect fluid
Color
Pink-Red (New fluid)
Brown (High mileage)
Black (Burnt fluid)
Frothy white-pink
Severe Aeration
Coolant leaking into the transmission
Smell
Procedures
Inspect the pan
Clutch material
Thin film on bottom of pan is normal on high mileage
transmissions
Metal flakes
Steel
Brass
Pieces of thrust washers
Where did they come from?
Pieces of gearsets
Funny looking little plug
Funny Looking Little Plug
When Ford
transmission are built
this plug is put in the
dipstick hole to seal it
When the dipstick is
installed on the
assembly line this pug
is just pushed into the
transmission
When servicing, it can
be thrown away Off-White Dipstick hole plug with
O-ring
Procedures
Clean the pan
Clean the magnet
Remove old filter and filter seal
IMPORTANT! – DO NOT leave the old seal in place
Install new seal, lubricate, and install filter
Install pan gasket, and torque to specifications
Do everything you can to ensure the pan does not
leak
Leak during service = Low fluid = Smoked
transmission = Your fault = $$$$
Procedures
Look up the fill capacity and required fluid type
Shopkey
Manuals
Add ½ Quart less than what is called for
Avoid overfilling
Start engine
Move shifter through all of the detents
Place transmission in park or neutral (Dodge)
Check fluid level
You may have to stick it a few times before you get a clear
reading because of transmission fluid hanging in the fill tube
Add and Recheck
Types of Fluid
Type F
High coefficient of friction
Used in older fords
When doing a rebuild, many clutch manufacturers recommend switching
to a Dexron fluid
Dexron I and II
Used in early GM and Chrysler Vehicles
Low coefficient of friction
Superceded by Dexron III
Dexron III
Currently the transmission fluid required in most transmissions
Mercon
Used in ford transmissions
Most fluid sold is a Dexron/Mercon universal fluid
7176 (ATF +2,3)
Used in late model Chrysler transmissions
Lower coefficient of friction
Honda ATF
Toyota T II
Fluid Properties
Viscosity - This is critical to the fluids’ ability to lubricate, function as
a hydraulic fluid and provide cooling.
Viscosity Retention - The ability of the fluid to maintain its viscosity
is critical to consistent shift quality over the life of the fluid
Oxidation Stability - This is the fluids’ ability to resist thickening as
it reacts with air & heat. Increasing operating temperatures make
this an important requirement.
Low Temp. Flow - The fluid cannot be allowed to thicken
excessively at cold temperatures. This is critical to maintaining
proper shift quality and pressure control.
Shear Stability - The fluid must be able to maintain its viscosity
under extremes of operation. If the fluid becomes too thin,
premature wear and hydraulic leaks will result.
Friction Properties - Friction modifiers are also added to the fluid to
ensure proper operation of the torque converter, bands, and
clutches. This is where the greatest difference in fluids lies.
Filter Seal