service FORD MUSTANG 1969 Volume One Chassis

06-01-02
General Transmission Service

06-01-02

REAR SEAL REPLACEMENT

1.
Remove the drive shaft.

2.
Remove the seal from the exten-

sion housing with the tool shown in

Fig. 2.

3.
Install the new seal in the exten-

sion housing with the tool shown in

Fig. 3.

4.
Install the drive shaft.

.REAR OIL SEAL

Tool-T61L-7657-A

EXTENSION HOUSING

C 1830.A

FIG. 3—Installing Extension

Housing Seal
Too/-7J75-AB

Tool-TSOT-lOO-A

FIG. 2—Removing Extension Housing Seal

EXTENSION HOUSING

Tool-T52L-7000-GAE

or 7000-G

C1O28-D

FIG. 4—Removing Extension

Housing Bushing and Seal
EXTENSION HOUSING
D
1927. A

Tool—T57P-7697-B

57-G

BUSHING

C 1832.A

FIG. 5—Installing Extension

Housing Bushing

REAR BUSHING AND SEAL

REMOVAL AND INSTALLATION

1.
Remove the drive shaft from the

vehicle.

2.
Insert the tool shown in Fig. 4

into the extension housing until it

grips on ihe front side of the bushing.
3.
Turn the screw clockwise until

the seal and the bushing are free of

the housing.

4.
Drive a new bushing into the ex-

tension housing with the tool shown in

Fig. 5.

5.
Install a new seal in the housing

as shown in Fig. 3.

6. Install the drive shaft.
LUBRICATION

Lubricant level should be even with

the bottom of the filler hole at the

right side of the transmission case.

CLEANING AND INSPECTION

CLEANING

1.
Wash all parts, except the ball

bearings and seals in a suitable clean-

ing solvent. Brush or scrape all foreign

matter from the parts. Be careful not

to damage any parts with the scraper.

Do not clean, wash or soak transmis-

sion seals in cleaning solvents. Dry all

parts with compressed air.

2.
Rotate the ball bearings in a

cleaning solvent until all lubricant is

removed. Hold the bearing assembly

to prevent it from rotating and dry it

with compressed air.

3.
Lubricate the bearings with ap-

proved transmission lubricant and

wrap them in a clean, lint-free cloth

or paper until ready for use.

4.
Clean the magnet welded to the

bottom of the case with kerosene or

mineral spirits.
INSPECTION

1.
Inspect the transmission case for

cracks, worn or damaged bearings

bores,
damaged threads or any other

damage that could affect the opera-

tion of the transmission.

2.
Inspect the front face of the case

for small nicks or burrs that could

cause misalignment of the transmis-

sion with the flywheel housing. Re-

move all small nicks or burrs with a

fine stone.

3.
Replace a cover that is bent or

distorted. Make sure that the vent

hole in the cover is open.

4.
Check the condition of the shift

levers, forks, shift rails and the lever

and shafts.

5.
Examine the ball bearing races

for cracks, wear or roughness. Inspect

the balls for looseness, wear, end play
or other damage. Check the bearings

for looseness in the bores. If any of

these conditions exist, replace the

bearings.

6. Replace roller bearings that are

broken, worn or rough.

7.
Replace the countershaft (clust-

er) gear if the teeth are chipped, brok-

en or worn. Replace the countershaft

if it is bent, scored or worn.

8. Replace the reverse idler gear or

sliding gear if the teeth are chipped,

worn or broken. Replace the idler

gear shaft if bent, worn or scored.

9. Replace the input shaft and gear

if the splines are damaged or if the

teeth are chipped, worn or broken. If

the roller bearing surface in the bore

of the gear is worn or rough, or if the

cone surface is damaged, replace the

gear and the gear rollers.

10.
Replace all other gears that areprocarmanuals.com

06-01-03

General Transmission Service

06-01-03

chipped, broken or worn.

11.
Check the synchronizer sleeves

for free movement on their hubs.

Make sure that the alignment marks

(etched marks) are properly indexed.

12.
Inspect the synchronizer block-

ing rings for widened index slots,

rounded clutch teeth and smooth in-

ternal surfaces (must have machined

grooves). With the blocker ring on the
cone,
the distance between the face of

the blocker ring and the clutch teeth

on the gear must not be less than

0.010 inches.

13.
Replace the speedometer drive

gear if the teeth are stripped or dam-

aged. Make certain to install the cor-

rect size replacement gear.

14.
Replace the output shaft if

there is any evidence of wear or if any
of the splines are damaged.

15.
Inspect the bushing and the seal

in the extension housing. Replace

them if they are worn or damaged.

The bushing and/or seal should be re-

placed after the extension housing has

been installed on the transmission.

16.
Replace the seal in the input

shaft bearing retainer.

17.
Replace the seals on the cam

and shafts.procarmanuals.com

06-02-02
Ford Design Three Speed Transmission

06-02-02

DESCRIPTION

DESCRIPTION

The RAN and RAT Model three-

speed transmission (Fig. 1) are used

on models having 170, 200, 240, 250,

302,
351 and 390 C.I.D. engines. The

specifications of this section, Part 6-4,

lists the transmission model numbers

and vehicles in which they are used.

A transmission service identification
tag is located on the right side of the

case at the front (Fig. 2). The first

line on the tag will show the transmis-

sion model and service identification

code when required. The second line

will show the transmission serial num-

ber. Additionally, a driveline compo-

nent identification tag is attached to

the upper right side of the transmis-

sion case.
This transmission is of the fully

synchronized type, with all gears ex-

cept the reverse gear and sleeve being

in constant mesh. All forward-speed

changes are accomplished with syn-

chronizer sleeves.

The forward-speed gears are

helical-cut and are in constant mesh.

Gears used in the reverse gear train

are spur-cut and are not synchronized.

C2O87-A

FIG.
1—Three-Speed
Transmission—Typical
TRANS.
MODEL

SERIAL
NO.

C 2089-A

FIG.
2—Transmission
Identification

Tag

IN-VEHICLE ADJUSTMENTS
AND
REPAIRS

GEAR SHIFT LINKAGE

ADJUSTMENT—COLUMN

MOUNTED

1. Place the gear shift lever in the

neutral position.

2.
Loosen the two gear shift rod

adjustment nuts.

3.
Check shift levers on transmis-

sion to be in neutral position.

4.
Insert a 3/16-inch diameter

alignment tool through the first and

reverse gear shift lever, the second and

third gear shift lever and both holes

in the lower casting (Fig. 3). An align-

ment tool can be made from 3/16

inch drill rod bent to an L shape.

The extensions should be 1 inch and 2

inches from the elbow. The short end

of the tool should be inserted into the

alignment holes.

5.
Tighten the two gear shift rod

adjustment nuts.

6. Remove the alignment tool from

the levers.

7.
Start the engine and shift the se-

lector lever to each position to make

sure it operates freely.
FIG.
3—Gearshift
Linkage Adjustment—Typicalprocarmanuals.com

06-03-02
Ford Design Four-Speed Transmission

06-03-02

1 DESCRIPTION

DESCRIPTION

The Ford designed 4-speed trans-

mission
(Fig. 1) is of the
fully
syn-

chronized type with
all
gears except

the reverse sliding gear being
in con-

stant mesh.
All
forward-speed changes

are accomplished with synchronizer

sleeves.
All forward-speed gears
in the

transmission
are
helical-type, however,

the reverse sliding gear
and the
exter-

ior
of the
first-and second-speed
syn-

chronizer sleeve
are
spur-type gears.

The specifications
of
this section Part

6-4 lists
the
transmission model
num-

bers
and
vehicles
in
which they
are

used.

C 1765-B

FIG. 7—Four-Speed Transmission—Typical
A transmission service identification

tag
is
located
on the
right side
of the

case
at the
front
(Fig. 2). The
first

line
on the tag
will show
the
transmis-

sion model
and
service identification

code when required.
The
second line

will show
the
transmission serial
num-

ber. Additionally,
a
driveline compo-

nent identification
tag is
attached
to

the upper right side
of the
transmis-

sion case.

TRANS.
MODEL

O
RUG-C-2

10001
O

SERIAL NO.

C 2088-A

FIG. 2—Transmission

Identification
Tag

IN-VEHICLE ADJUSTMENTS
AND
REPAIRS

SHIFT LINKAGE ADJUSTMENT

1.
Loosen
the
three shift linkage

adjustment nuts. Install
a 1/4
inch
di-

ameter alignment tool through
the

control bracket
and
lever holes
as

shown
in Fig. 13.

An alignment tool
can be
made

from
1/4
inch diameter drill
rod
bent

to
an "L"
shape.
The
extensions
should
be 2 1/2
inch
and 3 3/4
inch

from
the
elbow. Short
end of
align-

ment
pin
should
be
inserted into
con-

trol bracket
and
linkage holes until
it

bottoms.

2.
Disconnect
the
reverse gear shift

rod from
the
shift lever.

3.
Shift
the
transmission into
re-

verse gear.
4.
Tighten
the 1-2 and 3-4
shift
rod

adjustment nuts.

5.
Connect
the
reverse gear shift

rod
to the
shift lever. Shift
the
reverse

lever
to the
neutral position
and
tight-

en
the
adjustment
nut.

6. Remove
the
alignment
pin.

7.
Check
the
gear shift lever
for a

smooth crossover.

REMOVAL
AND
INSTALLATION

REMOVAL

1.
Raise
the
vehicle
on a
hoist.

2.
Mark
the
driveshaft
so
that
it

may
be
installed
in the
same relative
position. Disconnect
the
drive shaft

from
the
rear U-joint flange. Slide
the

drive shaft
off the
transmission output

shaft
and
install
the
extension housing

seal installation tool into the extension
housing
to
prevent lubricant leakage.

See
Fig. 2,
Part
6-1.

3.
Disconnect
the
speedometer

cable from
the
extension housing.

4.
Disconnect
the
parking brakeprocarmanuals.com

07-01-01

07-01-01

*.v:;V*>
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'y.y... -4^*:
GROUP

7

PART
7-1
PAGE

General Transmission Service
07-01-01

PART
7-2

C4 Automatic Transmission
07-02-01

PART
7-3

FMX Transmission
07-03-01
PART
7-4

C6 Automatic Transmission
....

PART
7-5

Specifications
PAGE

07-04-01

07-05-01

TRANSMISSION

CODE
TRANSMISSION

TYPE

AUTOMATIC
(C4)

U AUTOMATIC
(C6)

X AUTOMATIC
(FMX)

Z AUTOMATIC
(C6
SPECIAL)

D2040-A

FIG. 1—Typical Warranty Plate—Transmission Identification

PART
7-1
General
Transmission
Service

COMPONENT INDEX

AIR PRESSURE CHECKS

ANTI-STALL DASHPOT CLEARANCE

CHECK

(Engine Compartment)

CASE (Transmission)

Inspection

CONTROL PRESSURE CHECK

CONTROL VALVE BODY

Inspection

CONVERTER

Checking

Cleaning

DRAIN AND REFILL (Transmission)

ENGINE IDLE SPEED CHECK

EXTENSION HOUSING INSPECTION

FLUID AERATION CHECK
MODEL APPLICATION
All
Models

01-06

01-04

01-17

01-05

01-17

01-04

01-11

01-08

01-04

01-15

01-03
Ford
Mercury
Meteor
Cougar
Fairiane
Falcon
Montego
Mustang
Lincoln-
Continental
Thunderbird
Continental-
Mark
III

A page number indicates that the item
is for
the vehicle listed
at
the head
of
the column.

N/A indicates that the item
is not
applicable
to
the vehicle listed.
procarmanuals.com

07-01-02

General Transmission Service

07-01-02

COMPONENT INDEX

FLUID LEAKAGE CHECK

FLUID LEVEL CHECK

FRONT CLUTCH (Forward) INSPECTION

C4 Transmission

C6 Transmission

FMX Transmission

FRONT PUMP AND STATOR SUPPORT

Inspection

FRONT SERVO (Intermediate) INSPECTION

C4 Transmission

C6 Transmission

FMX Transmission

GOVERNOR INSPECTION

HYDRAULIC SYSTEM BENCH TESTS

(FMX)

Pressure Tests

Testing Tool Installation

MANUAL LINKAGE CHECKS

MANUAL SHIFT LINKAGE GROMMET

COLUMN SHIFT

Removal and Installation

NEUTRAL START SWITCH-COLUMN

SHIFT

Adjustment

Removal and Installation

OIL COOLER CLEANING

OIL COOLER TUBES

Removal and Installation

ONE-WAY CLUTCH INSPECTION

OUTPUT SHAFT AND PRIMARY SUN

GEAR

Shaft (FMX)

Inspection

PINION CARRIER, ONE-WAY CLUTCH

AND CENTER SUPPORT (FMX)

Inspection

PINION CARRIERS INSPECTION

C4 Transmission

C6 Transmission

PRESSURE REGULATOR (FMX)

Inspection

REAR CLUTCH (Reverse-High) INSPECTION

C4 Transmission

C6 Transmission

FMX Transmission

REAR SERVO (Low-Reverse) INSPECTION

C4 Transmission
MODEL APPLICATION
All
Models

01-03

01-03

01-16

01-17

01-04

01-11

01-08

01-17
Ford
01-16

01-16

01-16

01-17

01-17

01-17

01-08

01-07

01-11

01-09

01-10

01-12

01-15

01-15

01-15

01-17

01-16

01-16

01-16

01-17

01-17
Mercury
N/A

01-16

N/A

N/A

01-17

N/A

N/A

N/A

01-11

01-09

01-10

N/A

N/A

N/A

01-15

N/A

N/A

01-16

N/A

N/A

N/A
Meteor
01-16

01-16

01-16

01-17

01-17

01-17

01-08

01-07

01-11

01-09

01-10

01-12

01-15

01-15

01-15

01-17

01-16

01-16

01-16

01-17

01-17
Cougar
N/A

01-16

01-16

N/A

01-17

01-17

01-08

01-07

N/A

N/A

N/A

01-12

01-15

N/A

01-15

01-17

N/A

01-16

01-16

N/A

01-17
Fairlane
01-16

01-16

01-16

01-17

01-17

01-17

01-08

01-07

01-11

01-09

01-10

01-12

01-15

01-15

01-15

01-17

01-16

01-16

01-16

01-17

01-17
Falcon
01-16

N/A

N/A

01-17

N/A

N/A

N/A

N/A

01-11

01-09

01-10

N/A

N/A

01-15

N/A

N/A

01-16

N/A

N/A

01-17

N/A
Montego
01-16

01-16

01-16

01-17

01-17

01-17

01-08

01-07

01-11

01-09

01-10

01-12

01-15

01-15

01-15

01-17

01-16

01-16

01-16

01-17

01-17
Mustang
01-16

01-16

01-16

01-17

01-17

01-17

01-08

01-07

N/A

N/A

N/A

01-12

01-15

01-15

01-15

01-17

01-16

01-16

01-16

01-17

01-17
Lincoln-
Continental
N/A

01-16

N/A

N/A

01-17

N/A

N/A

N/A

01-11

01-09

01-10

N/A

N/A

N/A

01-15

N/A

N/A

01-16

N/A

N/A

N/A
Thunderbird
N/A

01-16

N/A

N/A

01-17

N/A

N/A

N/A

01-11

01-09

01-10

N/A

N/A

N/A

01-15

N/A

N/A

01-16

N/A

N/A

N/A
Continental-
Mark
III
N/A

01-16

N/A

N/A

01-17

N/A

N/A

N/A

01-11

01-09

01-10

N/A

N/A

N/A

01-15

N/A

N/A

01-16

N/A

N/A

N/A

A page number indicates that the item is for the vehicle listed at the head of the column.

N/A indicates that the item is not applicable to the vehicle listed.
procarmanuals.com

07-01-03

General Transmission Service

07-01-03

COMPONENT INDEX

FMX Transmission

REAR SUPPORT (FMX)

Inspection

SHIFT POINT CHECKS

STATOR ONE-WAY CLUTCH CHECK

STATOR TO IMPELLOR INTERFERENCE

CHECK

STATOR TO TURBINE INTERFERENCE

CHECK

TRANSMISSION CLEANING

TURBINE AND STATOR END PLAY

CHECK

VACUUM DIAPHRAGM ADJUSTMENT

Altitude Compensating Type

Non-Altitude Compensating Type

VACUUM UNIT CHECK

Altitude Compensating Type

Non-Altitude Compensating Type
MODEL APPLICATION
All
Models

01-06

01-12

01-12

01-12

01-11

01-12
Ford
01-17

01-16

N/A

01-08

N/A

01-05
Mercury
N/A

N/A

N/A

01-08

N/A

01-05
Meteor
01-17

01-16

N/A

01-08

N/A

01-05
Cougar
01-17

01-16

N/A

01-08

N/A

01-05
Fairlane
01-17

01-16

N/A

01-08

N/A

01-05
Falcon
N/A

N/A

N/A

01-08

N/A

01-05
Montego
01-17

01-16

N/A

01-08

N/A

01-05
Mustang
01-17

01-16

N/A

01-08

N/A

01-05
Lincoln-
Continental
N/A

N/A

01-09

N/A

01-06

N/A
Thunderbird
N/A

N/A

01-09

N/A

01-06

N/A
Continental-
Mark
III
N/A

N/A

01-09

N/A

01-06

N/A

A page number indicates that the item is for the vehicle listed at the head of the column.

N/A indicates that the item is not applicable to the vehicle listed.

Three different three-speed trans-

missions are used. The C4 Automatic,

C6 Automatic and the FMX Auto-

matic. Part 7-1 covers testing, com-
mon adjustments and repairs, and

cleaning and inspection for the three

types of transmissions. Where there
are differences in procedures or speci-

fications, the type of transmission af-

fected will be designated.

l
AUTOMATIC TRANSMISSION TESTS

When diagnosing transmission

problems, refer to the Ford Car and

Truck Diagnosis Manual for the de-

tailed information on the items that

could be causing the problem.

The following preliminary checks

should be made before proceeding

with other diagnosis checks.

TRANSMISSION FLUID LEVEL

CHECK

1.
Make sure that the vehicle is

standing level. Then firmly apply the

parking brake.

2.
Run the engine at normal idle

speed. If the transmission fluid is cold

run the engine at fast idle speed

(about 1200 rpm) until the fluid reach-

es its normal operating temperature.

When the fluid is warm, slow the en-

gine down to normal idle speed.

3.
On a vehicle equipped with a

vacuum brake release, disconnect the

release line and plug the end of the
line;
otherwise the parking brake will

not hold the transmission in any drive

position.

4.
Shift the selector lever through

all positions, and place the lever at P.

Do not turn off the engine during the

fluid level checks.

5.
Clean all dirt from the transmis-

sion fluid dipstick cap before remov-

ing the dipstick from the filler tube.

6. Pull the dipstick out of the tube,

wipe it clean, and push it all the way

back into the tube. Be sure it is prop-

erly seated.

7.
Pull the dipstick out of the tube

again, and check the fluid level. The

fluid level should be above the ADD

mark. If necessary, add enough fluid

to the transmission through the filler

tube to bring the level between the

ADD and FULL marks on the dip-

stick. Do not overfill the transmission.

Install the dipstick, making sure it is

fully seated in the tube.
8. Connect the vacuum brake re-

lease line if so equipped, and test it

for proper operation.

FLUID AERATION CHECK

A fluid level that is too high will

cause the fluid to become aerated:

Aerated fluid will cause low control

pressure, and the aerated fluid may be

forced out the vent.

Check the transmission fluid level.

Low fluid level can affect the opera-

tion of the transmission, and may in-

dicate fluid leaks that could cause

transmission damage.

TRANSMISSION FLUID

LEAKAGE CHECKS

Check the speedometer cable con-

nection at the transmission. Replace

the rubber seal if necessary.

Leakage at the oil pan gasket often

can be stopped by tightening the at-
procarmanuals.com

07-01-04
General Transmission Service

07-01-04

taching bolts to the proper torque. If

necessary, replace the gasket.

Check the fluid filler tube connec-

tion at the transmission case or pan.

If leakage is found here, install a new

O-ring or tighten the fitting to the

specified torque.

Check the fluid lines and fittings

between the transmission and the

cooler in the radiator tank for loose-

ness,
wear, or damage. If leakage can-

not be stopped by tightening a fitting,

replace the damaged parts.

Check the engine coolant in the ra-

diator. If transmission fluid is present

in the coolant, the cooler in the radia-

tor is probably leaking.

The cooler can be further checked

for leaks by disconnecting the lines

from the cooler fittings and applying

50-75 psi air pressure to the fittings.

Remove the radiator cap to relieve the

pressure build at the exterior of the oil

cooler tank. If the cooler is leaking

and will not hold this pressure the

cooler must be replaced. Cooler re-

placement is described in the Cooling

System Section of Group 11.

If leakage is found at either the

downshift control lever shaft or the

manual lever shaft, replace either or

both seals.

Inspect the pipe plug on the left

side of the transmission case at the

front. If the plug shows leakage, tor-

que the plug to specifications. If tight-

ening does not stop the leaks, replace

the plug. On a C6 transmission, a TV

pressure plug is also provided on the

right rear side of the case.

When converter drain plugs leak,

remove drain plugs with a six-point

wrench. Coat the threads with FoMo-

Co Perfect Seal Sealing Compound or

its equivalent, and install the plugs.

Torque the drain plugs to specifica-

tion. Fluid leakage from the converter

housing may be caused by engine oil

leaking past the rear main bearing or

from oil gallery plugs, or power steer-

ing oil leakage from steering system.

Be sure to determine the exact cause

of the leak before repair procedures

are started.

Oil-soluble aniline or fluorescent dyes

premixed at the rate of 1/2 teaspoon

of dye powder to 1/2 pint of transmis-

sion fluid have proved helpful in locat-

ing the source of the fluid leakage.

Such dyes may be used to determine

whether an engine oil or transmission

fluid leak is present or if the fluid in

the oil cooler leaks into the engine

coolant system. A black light, how-

ever, must be used with the fluorescent

dye solution.
DISHED OR

FLAT WASHER

" O.D.,
a" STEEL PLATE

5/8"X \W,

DRILL TO SUIT
HEX. HEAD SCREW

3/8"-24 X Vl

HEX. NUT W—
24

WELD

TOGETHER

WING
NUT

>/2"_13
THREAD

CHAIN,
10"
LONG
RUBBER PLUG

1
Vi" DIA. X 2"

LONG Vl"

HOLE THRU

APPROXIMATELY

40 DUROMETER
FLAT WASHER

Vs" O.D.

PLUG

VALVE
STANDARD BOLT

W-13
X 4Vl"

LONG SQUARE

THREAD
END

REMOVE HEAD

AND WELD
TO

WASHER

STANDARD 1/8" FITTING-87971-S FOR

RETAPPED DRAIN PLUG THREADS-USE

1/4" OVERSIZE FITTING-87973-S

D 1067-B
WELD TOGETHER

SECURELY—MUST

NOT LEAK

FIG. 2—Converter Leak Checking Tool

CONVERTER LEAKAGE

CHECK

If there are indications that the

welds on the torque converter are

leaking, the converter will have to be

removed and the following check

made before the unit is replaced.

A leak checking tool (Fig. 2) can be

made from standard parts. The tool

can be used to check all converters.

1.
Install the plug in the converter

(Fig. 3) and expand it by tightening

the wing nut. Attach the safety chains.

2.
Install the air valve in one of the

drain plug holes.

3.
Introduce air pressure into the

converter. Check the pressure with a

tire gauge and adjust it to 20 psi.

4.
Place the converter in a tank of

water. Observe the weld areas for

bubbles. If no bubbles are observed, it

may be assumed that the welds are

not leaking.

ENGINE IDLE SPEED CHECK

Check and, if necessary, adjust the

engine idle speed, using the procedure

given in Group 10.

If the idle speed is too low, the en-

gine will run roughly. An idle speed

that is too high will cause the vehicle

to creep, have harsh engagements and

harsh closed-throttle downshifts.
ANTI-STALL DASHPOT

CLEARANCE CHECK

After the engine idle speed has been

properly adjusted, check the anti-stall

dashpot clearance. Follow the proce-

dure given in Group 10 for checking

and adjusting this clearance.

MANUAL LINKAGE CHECKS

Correct manual linkage adjustment

is necessary to position the manual

valve for proper fluid pressure direc-

tion to the different transmission com-

ponents. Improperly adjusted manual

Tire Pressure Gauge

D1921-A

FIG. 3—Converter Leak Checking

Tool Installationprocarmanuals.com

07-01-05
General Transmission Service

07-01-05

linkage may cause crossleakage and

subsequent transmission failure. Refer

to Linkage Adjustments in Part 7-2,

7-3 or 7-4 for detailed manual linkage

adjustment procedures.

CONTROL PRESSURE

CHECK

When the vacuum diaphragm unit is

operating properly and the downshift

linkage is adjusted properly, all the

transmission shifts (automatic and

kickdown) should occur within the

road speed limits specified in Part 7-5.

If the shifts do not occur within

limits or the transmission slips during

shift point, the following procedure is

suggested to determine engine, trans-

mission, linkage, vacuum diaphragm

unit or valve body problems.

1.
Using the automatic transmis-

sion tester (Fig. 4), attach the tachom-

eter to the engine and the vacuum

gauge to the transmission vacuum line

at the vacuum unit (Fig. 5).

D 1823-A

. 4—Rotunda ARE-2905

Automatic Transmission Tester

T - FITTING
2.
Attach the pressure gauge to the

control pressure outlet at the trans-

mission (Figs. '., and 7).

3.
Firmly apply the parking brake

and start the engine.

On a vehicle equipped with a vacu-

um brake release, apply the service

brakes. The parking brake can not be

used because the brake automatically

VACUUM DIAPHRAGM UNIT

CLIP

I

| CONTROL PRESSURE TAKE-OFF HOLE

D2041-A

FIG. 6—Typical Vacuum

Diaphragm and Control Pressure

Connecting Point
releases when the transmission selec-

tor lever is moved to a drive position.

4.
Adjust the engine idle speed lo

the specified rpm. If the engine idle

speed cannot be brought within limits

by adjustment at the carburetor idle

adjustment screw, check the throttle

and downshift linkage for a binding

condition. If the linkage is satisfacto-

ry, check for vacuum leaks in the

transmission diaphragm unit (Fig. 8

or 9) and its connecting tubes and

hoses.
Check all other vacuum oper-

ated units (such as the power brake)

for vacuum leaks.

VACUUM UNIT CHECK

NON-ALTITIDE

COMPENSATING TYPE

To check the vacuum unit for dia-

phragm leakage, remove the unit from

the transmission. Use a distributor

D1840-A

FIG. 8—Testing Transmission

Vacuum Unit for Leakage

VACUUM DIAPHRAGM

D 1643 -C

FIG. 5—Typical Vacuum Test

Line Connections
FIG.
7—Vacuum
Diaphragm and Control and TV Pressure Connecting

Points—C6 Transmissionprocarmanuals.com

07-01-06
General Transmission Service

07-01-06

MAKE MARK HERE

BELLOWS INTACT
BELLOWS FAILED

FIG. 9—Checking Vacuum Unit Bellows

tester equipped with a vacuum pump

(Fig. 8). Set the regulator knob so

that the vacuum gauge reads 18 inches

with the end of the vacuum hose

blocked off.

Then connect the vacuum hose to

the transmission vacuum unit. If the

gauge still reads 18 inches, the vacuT

urn unit diaphragm is not leaking. As

the hose is removed from the trans-

mission vacuum unit, hold a finger

over the end of the control rod. When

the hose is removed, the internal

spring of the vacuum unit should push

the control rod outward.

ALTITUDE

COMPENSATING-TYPE

The vacuum diaphragm should be

checked for ruptured or damaged bel-

lows.
Check the diaphragm assembly

as follows:

1.
Remove the diaphragm and

throttle valve rod from the transmis-

sion.

2.
Insert a rod into the diaphragm,

making sure that the rod is buttonec

in the hole. Make a reference mark on

the rod where it enters the diaphragm

hole.

3.
Hold the assembly in such a way

that the end of the rod is resting on

the weighing surface of a scale (Fig.

9).

4.
Gradually press down on the dia-

phragm assembly until the rod is

pressed into the diaphragm body. If

the reference mark on the rod is still
visible with 12 pounds of force regis-

tered on the scale, the bellows are in-

tact. If the mark disappears before 4

pounds of force is exerted, the bellows

have failed and the diaphragm must

be replaced. If the bellows are intact,

then perform various pressure checks.

SHIFT POINT CHECKS

Check the minimum throttle up-

shifts in D. The transmission should

start in first gear, shift to second, and

then shift to third, within the shift

points specified in the specification

section.

While the transmission is in third

gear, depress the accelerator pedal

through the detent (to the floor). The

transmission should shift from third to

second or third to first, depending on

the vehicle speed.

Check the closed throttle downshift

from third to first by coasting down

from about 30 mph in third gear. The

shift should occur within the limits

specified in the specification section.

When the selector lever is at 2, the

transmission can operate only in sec-

ond gear.

With the transmission in third gear

and road speed over 30 mph, the

transmission should shift to second

gear when the selector lever is moved

from D to 2 to 1. The transmission

will downshift from second or third to

first gear when this same manual shift

is made below approximately 25 mph

with a C4 transmission, 30 mph with
D 1791.A

a C6 transmission or 35 mph with an

FMX transmission. This check will

determine if the governor pressure and

shift control valves are functioning

properly.

During the shift point check opera-

tion, if the transmission does not shift

within specifications or certain gear

ratios cannot be obtained, refer to the

Ford Car and Truck Diagnosis Manu-

al to resolve the problem.

AIR PRESSURE CHECKS

A NO DRIVE condition can exist,

even with correct transmission fluid

pressure, because of inoperative

clutches or bands. Erratic shifts could

be caused by a stuck governor valve.

The inoperative units can be located

through a series of checks by subst-

ituting air pressure for the fluid pres-

sure to determine the location of the

malfunction.

To make the air pressure checks,

drain the transmission fluid and re-

move the oil pan and the control valve

body assembly. The inoperative units

can be located by introducing air pres-

sure into the transmission case passa-

ges leading to the clutches, servos, and

governor (Figs. 10, 11 or 12).

HYDRAULIC SYSTEM BENCH

TESTS (FMX TRANSMISSION)

After the transmission has been as-

sembled and is ready for installationprocarmanuals.com