Chrysler 2005 Crossfire SRT6 Service Manual page 3376

21 - 306 AUTOMATIC - NAG1 SERVICE INFORMATION
OPERATION
With low oil levels, the lubricating oil which flows con-
stantly out of the gearset, flows back to oil galley (2)
though the opening (6). If the oil level rises, the oil
presses the float (5) against the housing opening (6).
The float (5) therefore separates the oil gallery (2)
from the gearset chamber (1). The lubricating oil which
continues to flow out of the gearsets is thrown against
the housing wall, incorporated by the rotating parts
and flows back into the oil galley (2) through the upper
opening (arrow).
DIAGNOSIS AND TESTING
EFFECTS OF INCORRECT FLUID LEVEL
A low fluid level allows the pump to take in air along with the fluid. Air in the fluid will cause fluid pressures to be
low and develop slower than normal. If the transmission is overfilled, the gears churn the fluid into foam. This aer-
ates the fluid and causing the same conditions occurring with a low level. In either case, air bubbles cause fluid
overheating, oxidation and varnish buildup which interferes with valve and clutch operation. Foaming also causes
fluid expansion which can result in fluid overflow from the transmission vent or fill tube. Fluid overflow can easily be
mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF BURNT FLUID
Burnt, discolored fluid is a result of overheating which has four primary causes.
1. Internal clutch slippage, usually caused by low line pressure, inadequate clutch apply pressure, or clutch seal
failure.
2. A result of restricted fluid flow through the main and/or auxiliary cooler. This condition is usually the result of a
faulty or improperly installed drainback valve, a damaged main cooler, or severe restrictions in the coolers and
lines caused by debris or kinked lines.
3. Heavy duty operation with a vehicle not properly equipped for this type of operation. Trailer towing or similar high
load operation will overheat the transmission fluid if the vehicle is improperly equipped. Such vehicles should
have an auxiliary transmission fluid cooler, a heavy duty cooling system, and the engine/axle ratio combination
needed to handle heavy loads.
4. Low fluid level.
DIAGNOSIS AND TESTING - FLUID CONTAMINATION
Transmission fluid contamination is generally a result of:
• adding incorrect fluid
• failure to clean dipstick and fill tube when checking level
• engine coolant entering the fluid
• internal failure that generates debris
• overheat that generates sludge (fluid breakdown)
• failure to replace contaminated converter after repair
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