1991 FORD FESTIVA differential

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GENERAL INFORMATION
Manual Transmission Trouble Shooting
* PLEASE READ THIS FIRST *
INTRODUCTION
There are many times when the transmission is incorrectly blamed for shifting problems or noises that are actually caused by other reasons.
Shift difficulties are frequently caused by conditions outside of the transmission or transaxle. Typical conditions include: shift linkage, shift
cables, alignment of engine to transmission, worn engine mounts or clutch problems. Drive train noises may come from many sources such as
tires, road surfaces, wheel bearings, differentials, engine or exhaust system. Repairing or overhauling transmission will not cure these
problems.
No manufacturer makes a perfectly quiet transmission. Gear rollover noise is present in most constant mesh transmissions and will tend to
disappear when the clutch is disengaged or transmission is placed in gear. If clutch is properly adjusted, clutch release bearing noise will
disappear when release bearing is moved enough to slide release bearing away from pressure plate.
Trouble shooting can be helped by driving vehicle on a smooth level road to help eliminate tire and body noise. Note whether noise occurs on
acceleration, coasting, deceleration or steady driving conditions. Some problems may only occur when transmission is either hot or cold. Gear
lubricant that is too thick can cause hard shifting on cold mornings before engine is warm and vehicle has been driven.
MANUAL TRANSMISSION/TRANSAXLE TROUBLE SHOOTING NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
ConditionPossible Cause
Noisy In Forward GearsLow Gear Oil Level, Loose Bellhousing Bolts, Worn Bearings Or
Gears
Clunk On Deceleration (FWD Only)Loose Engine Mounts, Worn Inboard CV Joints, Worn Differential
Pinion Shaft, Oversized Side Gear Hub Counterbore in Case
Gear Clash When Shifting Forward GearsClutch Out Of Alignment, Shift Linkage Damaged Or Out Of
Adjustment, Gears Or Synchronizers Damaged, Low Gear Oil
Level
Transmission Noisy When Moving (RWD Only); Quiet In Neutral
With Clutch EngagedWorn Rear Output Shaft Bearing
Gear RattleWorn Bearings, Worn Gear Oil, Low Gear Oil, Worn Gears
Steady Ticking At Idle (Increases With RPM)Broken Tooth On A Gear
Gear Clash When Shifting Forward GearsWorn Or Broken Synchronizers, Faulty Clutch
Loud Whine In ReverseNormal Condition (1)
Noise When Stepping On ClutchFaulty Release Bearing, Worn Pilot Bearing
Ticking Or Screeching As Clutch Is EngagedFaulty Release Bearing, Uneven Pressure Plate Fingers
Click Or Snap When Clutch Is EngagedWorn Clutch Fork, Worn Pivot Ball, Worn Or Broken Front
Bearing Retainer
Transmission Shifts HardClutch Not Releasing, Incorrect Gear Oil, Shift Mechanism
Binding, Clutch Installed Backward
Will Not Shift Into One Gear, Shifts Into All OthersBent Shift Fork, Worn Detent Balls
Locked Into Gear, Cannot ShiftClutch Adjustment, Worn Detent Balls
Transmission Jumps Out Of GearPilot Bearing Worn, Bent Shift Fork, Worn Gear Teeth Or Face,
Excessive Gear Train End Play, Worn Synchronizers, Missing
Detent Ball Spring, Shift Mechanism Worn Or Out Of Adjustment,
Engine Or Transmission Mount Bolts Loose, Transmission Not
Aligned
Shift Lever RattleWorn Detents Or Shift Lever, Worn Shift Fork, Worn
Synchronizer Sleeves
Shift Lever Hops Under AccelerationWorn Engine Or Transmission Mounts
(1)Most units use spur cut gears in Reverse and are naturally noisy.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00010942
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1988-94 AUT OMAT IC T RANSMISSIONS
Ford ATX Overhaul
APPLICATION
APPLICATION
DESCRIPTION
The transaxle consists of 3 main units: automatic transaxle, torque converter and differential assembly. The automatic transaxle consists of
front and rear clutches, one-way clutch, low-reverse brake assembly, oil pump and hydraulic controls (valve body and servo piston
assemblies). The valve body is controlled by the governor valve, vacuum throttle valve diaphragm (modulator) and kickdown solenoid. The
torque converter on the Aspire model is a mechanically operated (centrifugal type) torque converter clutch. See Fig. 1
.

Fig. 1: Transaxle Component Identification

Courtesy of FORD MOTOR CO.
LUBRICATION & ADJUSTMENTS
See the appropriate TRANSMISSION SERVICING - A/T article in this section. Refer to the following menu:
ON-VEHICLE SERVICE
BAND APPLY SERVO R & I
Removal
1. Raise and support vehicle. Remove left front wheel. Drain transaxle fluid. Remove valve body. See VALVE BODY . Remove front
stabilizer frame brackets. Carefully raise staked portion of left axle nut. Apply brakes and loosen, but DO NOT remove, axle nut.
Remove left lower control arm ball joint clamp bolt. Pry downward on lower control arm to separate control arm from knuckle.
2. Insert pry bar between transaxle case and left axle flange. Carefully apply force to pry bar until axle circlip is disengaged. Slide knuckle
assembly off axle shaft, and remove axle from vehicle. Quickly install appropriate plug in transaxle.
3. Loosen band adjusting stop and band adjusting stop nut. Remove band strut. Using "C" clamp and socket, compress servo piston into
transaxle case. See Fig. 2
. Remove snap ring. Remove servo retainer, servo piston and spring.
Installation
1. Lubricate servo piston with ATF. Assembly servo retainer, piston, piston large seal and spring. Insert assembly into transaxle. Usin g "C"
clamp and socket, compress assembly and install snap ring. See Fig. 2
. Install band strut to intermediate band. Install band adjusting
stop to band and tighten to 9-10 ft. lbs. (12-15 N.m). Loosen adjusting stop 3 turns. Install and tighten band adjusting stop nut. See
TORQUE SPECIFICATIONS
.
2. Install remaining components in reverse order of disassembly. Fill transaxle with fluid.
ApplicationTransmission
1988-89 Mercury TracerATX
1988-93 Ford FestivaATX
1994 Ford AspireATX
NOTE:T he AT X transaxle is used in som e Mazda m odels and is referred to as the F3A for those m odels. T he
AT X transaxle is also used in som e General Motors and Isuzu m odels and m ay be referred to as the
KF100, KF400 or RMC. Som e of the figures used in this article are courtesy of General Motors Corp. and
are valid figures for this Ford Motor Co. transaxle.
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Fig. 2: Compressing Band Apply Servo

Courtesy of FORD MOTOR CO.
DIFFERENTIAL OIL SEALS R & I
Removal
1. Raise and support vehicle. Drain transaxle fluid. Carefully raise staked portion of axle nut. Apply brakes and loosen, but DO NOT
remove, axle nut. Remove lower control arm ball joint clamp bolt. Pry downward on lower control arm to separate control arm from
knuckle.
2. Insert pry bar between transaxle case and axle flange. Carefully apply force to pry bar until axle circlip is disengaged. Slide knuckle
assembly off axle shaft, and remove axle from vehicle. Quickly install appropriate plug in transaxle. Using appropriate puller, remove
seal.
Installation
1. Apply lubrication to new seal. Using appropriate driver, install seal. Install new circlip on transaxle end of axle. Remove transaxle plug,
and carefully install axle into transaxle. Ensure circlip snaps into retaining groove.
2. Install axle into hub. Install NEW axle nut. Tighten bolts to specifications. See TORQUE SPECIFICATIONS
. Stake NEW axle nut
with blunt nose chisel. To complete installation, reverse removal procedure. Fill transaxle fluid to correct level.
OIL COOLER FLUSHING
Contaminates MUST be removed from oil cooler before transmission is put back into service. Replace cooler supply tubes if leaking.
Thoroughly flush oil cooler and lines if a major service or transaxle removal has occurred. It is recommended that a mechanically agitated
cleaner, such as Rotunda (014-00028), be used.
VACUUM THROTTLE VALVE DIAPHRAGM (MODULATOR) R & I
Removal
1. Drain transaxle fluid. Disconnect vacuum hose from modulator. Unscrew modulator from transaxle. Remove control rod. With beveled
side out, insert Vacuum Diaphragm Rod Gauge (T87C-77000-A) into mounting hole until gauge bottoms out.
2. Place gauge rod through opening of gauge until rod bottoms out against vacuum throttle valve. Tighten lock knob on gauge and remove
tool. Using depth gauge, measure distance from flat surface of gauge to end of rod. See Fig. 3
. Select proper length throttle valve rod.
See THROTTLE VALVE ROD DIMENSION CHART
.
THROTTLE VALVE ROD DIMENSION CHART
Installation
Install selected throttle valve rod. Coat threads of modulator with appropriate sealant. To install, reverse removal procedures.
NOTE:If replacing m odulator, it is necessary to replace throttle control valve rod.
Measurement In. (mm)Applicable Rod Length In. (mm)
1.0 (25.4)1.16 (29.5)
1.0-1.02 (25.4-25.9)1.18 (30.0)
1.02-1.04 (25.9-26.4)1.20 (30.5)
1.04-1.06 (25.9-26.4)1.22 (31.0)
1.06-1.08 (26.9-27.4)1.24 (31.5)
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Differential Noise
ATF contaminated or level incorrect. Bearings worn or has excessive preload. Teeth on gears worn or damaged or has excessive backlash.
TESTING
PARK/NEUTRAL SWITCH TEST
1. Ensure engine starts in "P" or "N". Ensure back-up lights glow when ignition is on and selector lever in "R". If park/neutral switch is not
operating properly, disconnect connector at transaxle and check continuity between terminals. See Fig. 4
. If continuity is not as
indicated, replace park/neutral switch.

Fig. 4: Testing Park/Neutral Switch

Courtesy of FORD MOTOR CO.
KICKDOWN (DOWNSHIFT) SOLENOID TEST
1.Check Fuse

Ensure ignition is off. Inspect condition of 15 amp METER fuse located in interior fuse junction panel. If fuse is okay, go to step 4). If
fuse is blown, go to next step.
2.Check System

Ensure ignition is off. Replace 15 amp fuse. Turn ignition on. If fuse blows, go to next step. If fuse is okay, go to step 4).
3.Check For Short To Ground

Turn ignition off. Remove 15 amp METER fuse. Disconnect kickdown switch harness connector. Check continuity between
Black/Yellow wire terminal of interior fuse holder and ground. If continuity exists, inspect and repair short circuit as needed. If
continuity does not exist, replace 15 amp fuse. Go to next step.
4.Check Power Supply To Kickdown Switch

Ensure ignition is off. Disconnect kickdown switch harness connector. Turn ignition on. Measure voltage between Black/Yellow wire
terminal of kickdown switch harness connector and ground. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less,
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snap ring. Release the "C" clamp and remove the servo piston. See Fig. 2 . R e mo ve go ve r n o r c o ve r a n d p u l l go ve r n o r fr o m t r a n sa xl e
case. Remove transaxle case-to-torque converter housing bolts. Separate case halves.
7. Remove differential assembly. Remove oil pipes and parking pawl assembly. Remove drum hub assembly. Remove one-way clutch inner
race assembly. See Fig. 8
. Remove rear planetary carrier with needle bearing and thrust washer. Before disassembling one-way clutch,
measure and record clearance between one-way clutch and low-reverse brake retaining plate. Clearance should .032-.041" (.8-1.05
mm).
8. Remove snap ring, one-way clutch and low-reverse brake retaining plate. Remove low-reverse brake plates. Compress low-reverse brake
piston with appropriate compressor. See Fig. 9
. Remove snap ring with screwdriver and remove low-reverse brake hub and springs.
Apply air pressure to low-reverse oil passage to remove piston. See Fig. 10
.
9. Remove output bearing and idler support assembly by lightly tapping on idler shaft with a soft-faced hammer. Drive out idler gear roll
pin and remove idler gear from output bearing and idler support. See Fig. 11
. Remove output gear assembly, press out bearing race
from output bearing and idler support and save adjusting shim for reassembly.

Fig. 9: Removing Snap Ring & Low
-Reverse Brake
Courtesy of FORD MOTOR CO.

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Fig. 10: Identifying Transaxle Oil Passages
Courtesy of FORD MOTOR CO.

Fig. 11: Torque Converter Housing Components

Courtesy of FORD MOTOR CO.
COMPONENT DISASSEMBLY & REASSEMBLY
BAND SERVO
Inspection
Remove seal rings and inspect piston for damaged or worn piston. Ensure spring free length is 1.890" (48.00 mm). If less than specified,
replace spring. Install new seal rings on piston and servo retainer.
DIFFERENTIAL
Disassembly
1. Remove ring gear retaining bolts and ring gear. Using hammer and pin punch, drive out roll pin. See Fig. 12. Push out pinion gear shaft.
Remove pinion and side gears, with washers, from differential housing.
2. Using appropriate puller, remove side bearings from differential housing. DO NOT remove speedometer drive gear unless damaged.
Removal will damage speedometer drive gear.
Inspection
Check all gears for signs of excessive wear or damage. Check differential gear case for cracks or other damage. Replace as needed.
Reassembly
1. Reverse removal procedure to reassemble. Measure side gear and pinion gear backlash by inserting drive shafts into differential side
gears and supporting shafts in "V" blocks. Position dial indicator with plunger resting on teeth of pinion gear. See Fig. 13
. Measure
backlash. Repeat procedure with plunger on other pinion gear.
2. Backlash readings should be less than .004" (.10 mm). If backlash is not within specification, adjust backlash by changing thrust
washers. Thrust washers are available in .079" (2.00 mm), .083" (2.10 mm) and .087" (2.20 mm) thicknesses. Use thrust washers of t h e
same thickness on both sides whenever possible.
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Fig. 12: Exploded View Of Differential Assembly

Courtesy of FORD MOTOR CO.

Fig. 13: Measuring Pinion Gear Backlash

Courtesy of FORD MOTOR CO.
DRUM HUB
Disassembly, Inspection & Reassembly
Remove parking gear spring from park gear. Push in the parking gear retaining pins with screwdriver and remove parking gear. See Fig. 14 .
Remove snap ring and lift internal gear assembly from drive hub. Check gear for excessive wear or damage and replace if needed. Reverse
disassembly procedure to reassemble drum hub.
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Fig. 24: Measuring Output Shaft Bearing Preload

Courtesy of FORD MOTOR CO.
3. Unthread gauge tool until output shaft bearings are seated and no play exists. Install Torque Adapter (T87C77000-E) over splined end
of output shaft. Using INCH lb. torque wrench, rotate output shaft while unthreading gauge tool. Unthread gauge tool until 4.42-7.97
INCH lbs. (.5-.9 N.m) of turning torque is obtained.
4. Using feeler gauge, measure gap of gauge tool. Select correct thrust shim(s) that match measured gauge tool gap. Shims are available
from in thicknesses of .004" (.10 mm) to .007" (.18 mm) in .02 mm increments. One shim is available in thickness of .019" (.50 mm).
5. Disassemble output bearing and idler support from converter housing. Remove gauge set and spacers. Install selected shim(s) in output
bearing and idler support. DO NOT exceed 7 shims. Remove bearing race from gauge tool and install race in support. Reassemble
converter housing and output bearing and idler support. Install bolts and tighten retaining bolts to specification. Refer to TORQUE
SPECIFICATIONS .
6. Install Torque Adapter (T87C77000-E) over splined end of output shaft. Using INCH lb. torque wrench, rotate output shaft to confirm
correct bearing preload. Turning torque should be .26-7.96 INCH lbs. (.03-.9 N.m). If turning torque is not within specification, repeat
steps 1) through 6).
7. Once correct output shaft bearing preload is obtained, remove output bearing and idler gear support. Replace idler gear shaft seal on
idler gear shaft. Install idler gear into converter housing. Install output gear and bearing support. Ensure alignment groove in idler gear
shaft is aligned with support ridge of output bearing and idler support.
8. Install new idler gear shaft roll pin. Install output gear and bearing support bolts and tighten bolts to specification. See TORQUE
SPECIFICATIONS .
DIFFERENTIAL BEARING PRELOAD ADJUSTMENT
1. Install differential assembly into converter housing. Position differential side bearing race in recessed end of Gauge Tool (T87C-
770002DJ). Place gauge tool on differential. See Fig. 25
.
2. Ensure gauge tool is completely threaded together so that no gap is present. Position spacer collars and assemble case halves using
supplied bolts and washers of tool set. See Fig. 25
. Tighten bolts to 22-34 ft. lbs. (292D46 N.m).
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