Ford THUNDERBIRD 2004 Owner's Manual page 208

Maintenance and Specifications
Item
Rear Axle
Lubricant
Automatic
transmission
fluid
Windshield
washer fluid
1
Use only brake fluids certified to meet Ford specifications. DOT 3 fluid
is recommended. However, if DOT 3 is not available, DOT 4 fluid can be
used.
2
Ford design rear axles contain a synthetic lubricant that does not
require changing unless the axle has been submerged in water.
3
Ensure the correct automatic transmission fluid is used. MERCON and
MERCON V are not interchangeable. DO NOT MIX MERCON and
MERCON V. Refer to the Scheduled Maintenance Guide to determine
the correct service interval.
ENGINE DATA
Engine
Displacement
Required fuel
Firing order
Ignition system
Compression ratio
208
Ford part
name
Motorcraft SAE
75W-90 Fuel
Efficient High
Performance
Synthetic Rear
Axle Lubricant
Motorcraft
MERCON V
3
ATF
Motorcraft
Premium
Windshield
Washer
Concentrate
Ford part
number
XY-75W90-QFEHP
2
XT-5-QM
ZC-32-A
3.9L-4V V8 engine
3 949 cc (241 cid)
91 octane
1-5-4-2-6-3-7-8
Coil on plug
10.75:1
Ford
specification
MERCON V
WSB-M8B16–A2