Ford Falcon. Manual - part 41

205-00-8 

Driveline System — General Information 

205-00-8

DIAGNOSIS AND TESTING (Continued)

Ideal Tooth Contact Pattern on Ring Gear

Acceptable Pattern

Faulty gear set.

The drive pattern shown was rolled on a hunting-type

Shim and Backlash Changes

gear set. Since each pinion tooth came into contact

with each ring gear tooth, the pattern is a result of the The patterns shown are typical of gear sets that have

combined tooth contacts. Therefore, the pattern is

either an incorrect backlash or an incorrect shim

uniform from tooth to tooth.

adjustment. Since each gear set rolls a characteristic

pattern, the patterns shown should be considered as

Acceptable Gear Tooth Contact Pattern

typical only and should be used as a guide rather than

a rigid standard. The drive pattern is rolled on the

convex side of the tooth, and the coast pattern is

rolled on the concave side.

Unacceptable Pattern
An erratic tooth pattern on a hunting gear set

indicates gear set runout and is caused by one of the

following conditions:

Foreign matter between differential hemisphere

gear locating base and back face of crown wheel.

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205-00-9 

Driveline System — General Information 

205-00-9

DIAGNOSIS AND TESTING (Continued)

Typical Gear Tooth Contact Patterns Indicating Shim or Backlash Change

2.  Chock the front wheels.

Driveline Vibration

3.  Raise the rear of the vehicle, remove one rear

For information regarding driveline, Refer to Section

wheel and attach the Special Tool No. E6662.

205-01.

4.  Lower the rear of the vehicle to simulate normal

Limited Slip Differentials (M78 & M86)

ride height (ie. For IRS, lower arms should be

horizontal to the ground).

Cone Chatter

5.  Place the transmission in neutral and release the

When encountering complaints of limited slip cone

park brake.

chatter, the vehicle should be warmed up for 10

6.  Ensure that there is no brake drag affecting wheel

minutes and then driven in tight circles (slightly less

rotation.

than full steering lock), five times clockwise and five

7.  Attach a torque meter to the special tool, and

times anti-clockwise at approximately 10 km/h to allow

rotate the axle.

lubricant to work in between the cone friction

surfaces.

The torque required to rotate the axle shaft for a used

M78 L.S.D. unit should be between 50 and 130 Nm.

If the chatter persists, drain the lubricant, refill the axle

Reading should be steady within 10 Nm.

with the specified lubricant and repeat the aforesaid

The torque required to rotate the axle shaft for a used

procedure. It may be necessary to drive the vehicle

M86 L.S.D. unit should be between 50 and 130 Nm.

10-20 km before re-evaluating to allow the new

Reading should be steady within 10 Nm.

lubricant to take affect. Should chatter still be evident,

dismantling of the differential for further inspection

and repair will be necessary. A whirring sound due to

over-running of the cones is no indication of LSD unit

failure.

In Vehicle Limited Slip Differential Torque Testing
To test the Limited Slip Differential (LSD) for correct

operation proceed as follows:

1.  Drive vehicle 10 km to warm up axle oil.

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205-00-10 

Driveline System — General Information 

205-00-10

DIAGNOSIS AND TESTING (Continued)

Drive Pinion Flange
Check the flange mating face for damage and wear.

The end of the flange contacting the bearing cone and

the seal surface must be free from surface

imperfections like burrs and scoring.

Carrier Casting
Make sure that the differential bearing bores are

smooth and the differential bearing preload spacer

abutment faces are not damaged.

Differential Case
Carefully examine the case bearing hubs for damage.

The bearing assemblies will fail if they do not seat

against the shoulder on the hubs correctly.

If the torque required to continuously rotate the wheel

is outside the specification check the differential for

Limited Slip Differential (LSD)

improper assembly and/or rework.

For M78 LSDs, thoroughly clean and dry all parts and

Inspection after Removal & Dismantling

check the following:

Thoroughly clean all parts. Always use new solvent

The cone seats in the case should be smooth and

when cleaning bearings. Oil the bearings immediately

free from excessive scoring. Slight grooves or

after cleaning to prevent rusting. Inspect the parts for

scratches are permissible and normal.

any major defects. Clean the inside of the case,

The land surfaces of the cones will duplicate the

particularly the oil ports, before rebuilding and

case surface condition. Excessive wear or

installing. Inspect individual parts as outlined below.

damaged cone surfaces will necessitate renewal

of the cone and casing.

Hypoid and Differential Gears

Inspect thrust springs for damage. Replace where

The pattern taken during dismantling should help in

necessary.

judging if the gears can be re-used. Worn gears

Check the thrust blocks for excessive wear.

cannot be rebuilt to correct a noisy condition. Gear

Replace where necessary.

scoring is the result of excessive shock loading or the

use of an incorrect lubricant. Scored gears must be

For M86 LSDs, thoroughly clean and dry all parts and

replaced. Examine the teeth and thrust surface of the

check the following:

differential gears.

The LSD plates and disc must be in good

condition. If any one member of either stack

NOTE: Check the fit of the side gear hubs in the case

shows evidence of excessive wear or scoring, the

on M78 conventional differentials. Wear on the hub of

complete stack is to be replaced on both sides of

the side gear can cause a “chuckling” noise known as

the assembly.

“chuckle” when the vehicle is driven at low speeds.

Side and pinion gears should be checked for

Wear on splines, thrust surfaces, or thrust washers

extreme wear and possible cracks. The external

can contribute to excessive driveline backlash.

teeth of the side gear, which retain the concentric

groove discs, should also be checked for wear or

Bearings

cracks.

Check bearing cups for rings, scores, galling or erratic

If replacement of one gear is required due to

wear patterns. Pinion bearing cups must be solidly

wear, etc., then both side gears, pinion mate

seated. Check by attempting to insert a 0.05 mm

gears, and washers are to be replaced.

feeler between the cups and the bottom of their bores.

If excessive wear is evident on the cross pin, it

The cone and roller assemblies on the differential

should be replaced.

case and the rear cone and roller on the pinion should

If wear is evident on any one of the clutch retainer

be checked before being removed from the differential

clips, all four clips must be replaced.

case or pinion. When these cones and rollers have

been removed the cones and rollers and their

If scoring, wear or metal pick-up is evident on the

respective bearing cups should be discarded. When

machined surfaces of the differential case, then

revolved in the cups, bearing rollers must turn without

replacement of the case is necessary.

roughness. Examine the roller ends for wear.

Stepwear on the roller ends indicates the bearing

preload was incorrect or the rollers were slightly

misaligned.

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205-01-1 Driveshaft 205-01-1

SECTION : 205-01 Driveshaft

VEHICLE APPLICATION : 2003.0 BA Falcon
CONTENTS  

PAGE

SPECIFICATIONS

 Specifications  .........................................................................................................................205-01-2

DESCRIPTION AND OPERATION

 Driveshaft  ...............................................................................................................................205-01-3

 Universal Joints  ......................................................................................................................205-01-3

DIAGNOSIS AND TESTING

 Driveshaft  ...............................................................................................................................205-01-4

  Inspection and Verification  ...................................................................................................205-01-4

 Symptom 

Chart 

 

....................................................................................................................205-01-5

GENERAL PROCEDURES

  Take — Off Shudder  ..............................................................................................................205-01-6

REMOVAL AND INSTALLATION

 Driveshaft Assembly  ..............................................................................................................205-01-7

DISASSEMBLY AND ASSEMBLY

  Flex Joint Replacement  .........................................................................................................205-01-8

  Universal Joint Replacement  .................................................................................................205-01-8

  Centre Bearing Replacement  .................................................................................................205-01-9

  CV Joint Replacement  .........................................................................................................205-01-10