Front Wheel Suspension - Redesigned

Section:
6

Group:
61

No.:
903

Date:
August 1994

RE:
Front wheel suspension

960

REFERENCE:
TP 31369/1, SECTION 6, 7 (60-64, 70-77), FRONT END, STEERING, 700 1982-19..

NEW FRONT WHEEL SUSPENSION AND FRONT END FOR 960

The changes made in the wheel suspension in the redesigned front end have provided the 1995 Volvo 960 with improved road handling characteristics and comfort. The front end has been largely redesigned, with the exception of the upper support of spring struts, mounted in the wheel housing turret.

Contents:

Front wheel angles 2
Tightening torque 2
New special tools 3
Design and operation 4
Power steering pump - mounting location of pulley changed 7
Replacement of ball joint 8
Replacement of control arm bushings 10
Spring, spring strut mounting, shock absorber, replacement 14
Replacement of steering gear - addition to procedure 18
Ball joint - tie rod, replacement 19

The work steps described in this service bulletin only cover those new items and changes that apply to the new front end. In other respects, refer to the work procedures in the current service manual referenced above.

Front wheel angles:

Camber angle -0,7° (+/-) 0,5° (42' (+/-) 30')
Camber angle, symmetry error max 0,7° (42')
Caster angle 6,0° (+/-) 0,5°
Toe-in (rolling) a 18' (+/-) 8'

Camber angle adjustment is done according to description in the service manual: Front end, Steering, sect. 6, 7 (60-64, 70-77).




TOE-IN





Toe-in:
All measurements are made with the car empty. Measurements are taken at the height of the hub as an angular measurement a, or as the difference between front and back edges of the wheel in points A, B, or C (tread of the tire, shoulder and flare of the rim, respectively)





Tightening Torque











The New Special Tools





Design and Operation

NEW CONTROL ARM WITH MORE RIGID MOUNTING
The relatively complicated design consisting of both a control arm and control arm bar has been replaced by a cast control arm (1) of cast steel. Control arm rear mounting (2) to the side beams is connected with a strong tubular rod (3). This provides a very rigid mounting as both side beams combine to absorb forces applied through the front end. The main purpose of the cross member is, however, to improve the protection in offset collisions. As before, front control arm mounting is done in front crossbeam (4) which has been strengthened as well. The strengthened mounting reduces the propagation of sound in the body.

INCREASED ROLLING STIFFNESS
The effect of the anti-roll bar (5) is considerably greater than before, although the diameter is the same (23 mm). The reason is partly that the anti-roll bar is directly affecting the spring strut via the anti-roll bar link (6), instead of via the control arm as before, and partly because all rubber links have been replaced with ball joints. The rolling stiffness of Volvo 960 is now at the level of that of Volvo 850.

NEUTRAL STEERING
The car has been given more neutral steering e.g. by increasing the rolling stiffness more in the rear end than in the front.

SOFTER SPRINGS AND SHOCK ABSORBERS
Spring (7) and shock absorber (8) are softer than before, in order to:
- Make the car more comfortable and accommodating on the ground.
- Remove some of the tendency for bouncing while going over an obstacle, and thereby provide the car with a more even ride over larger obstacles.

LOWER FORCES ON THE STEERING WHEEL
In order to reduce the forces on the steering wheel, the steering gear has been changed using a new pinion (9) and torsion bar, something which has changed the working pressure on the servo oil within the steering gear. Length and shape of the tie rod (10) have also been adjusted for the new front end.





INCREASED WHEEL OFFSET FROM 25 TO 33 MM
The rims have a greater offset (a), i.e. the mounting plane of the rims toward the brake disc is located further out. The wheel offset, which now is the same as for 850, implies that the brake discs (1) and the hub have also been changed.

If rims with incorrect offset are mounted, this will alter the front end geometry at the risk of both inferior road handling characteristics and the tire hitting the edge of the fender. Using for example earlier rims for the 900 in the 960, or vice versa, is not allowed!

BALL JOINT MOVED OUT - REDUCED SENSITIVITY TO WHEEL IMBALANCE

Ball joint (2) has been moved further out, which has greatly affected the entire front end geometry, with the exception of toe-in angle, which is unchanged. As before, the toe-in angles are adjusted by adjusting the tie rod length.

Moving the ball joint out has produced a greater king pin angle (b), which has reduced the so-called lever effect (c). The new front end is thus less sensitive to vibrations caused by wheel imbalance, and this contributes to improved brake quality.

GROUND OFFSET CHANGED
Ground offset (d), i.e. the distance, measured on road surface, between wheel drive axle and wheel center line, has been changed from a positive dimension of 33 mm to become slightly negative (-3 mm). This will reduce the tendency of the car to tilt while decelerating (when the force is received from the center line of the wheel) which primarily happens when the tires have a different traction against the road surface.

IMPROVED ROAD-HOLDING ABILITY
Track width has been increased from 1471 mm to 1502 mm. This, along with a change of camber angle (e), from +0,3° to -0,7°, means that the road-holding ability has been improved as the wheel will remain largely vertical, with little rolling. This also has a positive effect on tire wear.

BOLT MOUNTING BETWEEN SPRING STRUT AND SPINDLE
The spring strut mounting to the spindle is done using bolt mounting (3). The ball joint, now affected directly by the tie rods, has been moved further out, something which has greatly affected the entire front end geometry, with the exception of the toe-in angle, which is unchanged.

GOOD STEERING WHEEL FEEL EVEN AT HIGHER SPEEDS
In order to maintain a good feel for the road in the steering wheel while driving at higher speeds, in spite of increased power steering effect, the latter has been compensated by a greater caster offset in such a way that, following a turn, the steering wheel bears quicker and more firmly toward the neutral position

SMALLER TURNING DIAMETER
Thanks to the new front end, it has been possible to introduce more favorable wheel angles for cornering. These have been changed in such a way that while making a turn, the inner wheel turns more as compared to previous front end designs. As a result, the car performs sharp turns in a more comfortable way with less tire wear, and the turning diameter has been reduced from 9,9 m to 9,7 m.

NEW RIMS
Besides the fact that rims with a new design have been developed for the new 960 with the changed offset, there are the following other important changes to point out:
- The spare tire of 960 has been redesigned. The wheel is built to have full stability with or without ABS control. It is the same type as the one used for 850, but different in tire size and offset
Thus mixing them is not allowed!
- Winter wheels of the 1995 model of 960 will have the 195/65 tire.

Power steering pump of B6254 and B6304 engines

The pulley of the power steering pump has a new mounting location. The reason is that the cam belt width of these engines has been increased to 28 mm. However, the grip length of the pulley on the pump shaft is unchanged.





PLACEMENT OF THE PULLEY
Mounting location:
Press the pulley in, using tool 999 5244, until the distance between the center edge of the pulley and the end of the shaft of the power steering pump is (see picture):
L = 5,0 (+/-) 0,1 mm
Thus the center edge of the pulley will stick out ut past the end of the shaft.

A. BALL JOINT REPLACEMENT
Special tools: 981 4031, 999 5259

A1
RAISE THE CAR AND REMOVE THE FRONT WHEEL




A2
REMOVE:
- the ball joint stud retainer
- the control arm nut
- the wheel spindle bolts




A3
PULL THE CONTROL ARM LOOSE FROM THE BALL JOINT
Use puller 999 5259. Place the puller directly on the ball joint stud.
Remove the ball joint.




A4
INSTALL THE NEW BALL JOINT
Use new bolts for the wheel spindle.

First tighten the bolts alternately to 30 Nm (22 ft.lbs). Next tighten in a 90° angle.




A5
INSTALL THE CONTROL ARM NUT
Tighten to 70 Nm (52 ft.lbs).

Install the ball joint stud retainer.




A6
INSTALL THE WHEEL
Make sure that the brake disc and rim installation surfaces are clean. Lubricate the rim center guide of the hub. Use rust inhibitor, P/N 1161030-0.

Install the bolts loosely. Next tighten them crosswise to 85 Nm (63 ft.lbs). When tightening with a nut driver, use torque socket 981 4031.

Lower the car.

B. REPLACEMENT OF CONTROL ARM BUSHINGS
Special tools: 981 4031, 999 5259, -5581, -5582, -5583, -5584, -5585, -5586

B1
RAISE THE CAR, REMOVE THE WHEEL




B2
REMOVE:
- the ball joint stud retainer
- the control arm nut

B3
PULL THE CONTROL ARM LOOSE FROM THE BALL JOINT.
Use puller 999 5259. Place the puller directly on the ball joint stud.




B4
LOOSEN THE TRANSVERSE CROSSMEMBER AS FOLLOWS:
- Remove both (back) bolts used for mounting the crossmember to the body.
- Remove the front bolt (A) on the side of the car where the bushing is to be replaced.
- Loosen the front bolt a few turns on the opposite side of the crossmember.
- Twist back the crossmember.

B5
REMOVE BOLT (B) OF CONTROL ARM MOUNTING TO THE FRONT AXLE BEAM
Remove the control arm.

FRONT BUSHING REPLACEMENT



B6
Press the front bushing out

Use counterholder 999 5584 for support against the control arm and drift 999 5585. Press the bushing out.




B7
INSTALL THE NEW BUSHING

Use counterholder 999 5584 for support against the control arm and drift 999 5586, with the countersunk part toward the bushing.

Press the bushing in until the drift reaches the control arm.




B8
BACK BUSHING REPLACEMENT

Knock out the bushing collar around the bottom side of the control arm
Use a chisel.




B9
PRESS THE BUSHING OUT
Use counterholder 999 5582 for support against the control arm and drift 999 5561.

Press the bushing out.




B10
INSTALL THE NEW BUSHING
Place the bushing on counterholder 999 5583.
Use counterholder 999 5582 on the top side of the control arm.

Align both tools with the markings of the control arm and the bushing in such a way that the mounting location agrees with the picture inset.




B11
INSTALL THE CONTROL ARM

Install the bolt for the front bushing. (Placement is marked with A in the picture.) Push the control arm on the ball joint stud.

Note!
The bolt of the bushing should not be tightened yet

B12
INSTALL THE CROSSMEMBER TO THE CONTROL ARM AND BODY USING NEW BOLTS

Replace also the 2 bolts on the opposite side of the crossmember.
Tighten the bolts to 100 Nm (74 ft.lbs), tighten in the following sequence:

1. The bolts for control arm - crossmember (front bolts) on both sides.

2. The bolts for crossmember - body (back bolts).




B13
INSTALL A NEW NUT FOR THE BALL JOINT STUD

Tighten the nut to 70 Nm (52 ft.lbs). Install the ball joint stud retainer.




B14
PRESS THE CONTROL ARM UP TO ITS NORMAL POSITION
Lower the car to just above ground level. Verify that the car is steady on the lift.

Press the wheel spindle up using a jack, where the control arm comes to its normal (loaded) position.

Alternative:
Install the wheel according to 616 and then tighten according to B15 on a wheel alignment lift.

B15
TIGHTEN THE FRONT BUSHING BOLT (A) TO 90 NM (66 FT. LBS)

Note!
It is very important for the life span of the bushing and for the sound comfort that the front bushings of the control arm are tightened in their loaded position.




B16
INSTALL THE WHEEL

Make sure that the brake disc and rim installation surfaces are clean. Lubricate the rim center guide of the hub. Use rust inhibitor, P/N 116103-0.

Install the bolts loosely. Next tighten them crosswise to 85 Nm (63 ft.lbs). When tightening with a nut driver, use torque socket 961 4031.

C. SPRING, SPRING STRUT MOUNT, SHOCK ABSORBER, REPLACEMENT
Special tools: 981 4031, 999 5036, -5037, -5407

C1
RAISE THE CAR AND REMOVE THE WHEEL




C2
REMOVE THE ABS SENSOR FROM THE WHEEL SPINDLE

Remove the bolt of the ABS sensor (A). Loosen the ABS sensor cable from the spring strut (B).

C3
REMOVE THE NUT (C) OF THE ANTI-ROLL BAR LINK FROM THE SPRING STRUT

Tap out the link from the spring strut.

C4
LOOSEN BY A FEW TURNS THE NUTS (D) HOLDING THE SPRING STRUTMOUNT TO THE BODY

See the picture inset.




C5
SET THE JACK IN PLACE

Take out the wheel and position the jack under the control arm to support without lifting.

Note!
The setting of the jack is important in order to prevent the brake hose from stretching when the spring strut is removed from the wheel spindle.




C6
REMOVE THE SPRING STRUT

Remove the two bolts holding the spring strut in the wheel spindle.

Remove the nuts of the spring strut mount on the body.

Remove the spring strut.




C7
FASTEN THE SPRING STRUT IN A VISE, PULLING THE SPRING TOGETHER

Fasten the spring strut in a vise as shown in the picture. Release the spring using spring clamps 999 5407. Set the clamps facing each other.

Alternate tightening the spring clamps until the spring is compressed.




C8
REMOVE SHOCK ABSORBER NUT AND WASHER
Use socket 999 5036 and counterholder 999 5037.




C9
REMOVE:
- the spring strut mount
- the shock absorber washer
- the axial bearing
- the spring seat
- the rubber bumper
- guide sleeve protector

Check the parts for wear and damage.




C10
ASSEMBLE SLEEVE PROTECTOR, RUBBER BUMPER, AND SPRING SEAT

Install the axial bearing on the spring strut mount with the color marking turned up toward the spring strut mount.




C11
WHEN REPLACING THE SPRING:

Note!
Always loosen and tighten the spring clamps in alternating order.

Compress the spring to the length (L) at approx. 290 - 300 mm.




C12
ASSEMBLING THE SPRING STRUT

PULL THE SHOCK ABSORBER PISTON UP AS FAR AS IT GOES

Place the protector guide sleeve (A) and spring (B) on the strut.

C13
INSTALL PROTECTOR SLEEVE/RUBBER BUMPER/SPRING SEAT (C)

Verify that spring ends settle in correct locations, both in the upper and the lower spring seat, see arrows in the picture.

C14
INSTALL THE SHOCK ABSORBER WASHER AND THE SPRING STRUT MOUNT

Verify that the bearing is properly in place, see the preceding picture (work step C10).




C15
INSTALL THE WASHER AND THE NUT

Tighten the nut to 50 Nm (59 ft.lbs). Use socket 999 5036 and counterholder 999 5037.

C16
REMOVE THE SPRING CLAMPS

Loosen alternately using the tool 999 5407. Verify that spring ends settle in correct locations.

C17
MOUNTING OF THE SPRING STRUT

Install the spring strut in place in the spring strut turret

Mount the spring strut on the body using new nuts. Do not tighten the nuts yet.




C18
INSTALL THE SPRING STRUT ON THE WHEEL SPINDLE
Use new bolts and nuts.

Tighten to 65 Nm (48 ft.lbs). Then tighten at an angle with 90°.

C19
TIGHTEN THE NUTS (D) OF THE SPRING STRUT ASSEMBLY TO THE BODY TO 50 NM (37 FT.LBS)




C20
INSTALL THE ABS SENSOR (A) TO THE WHEEL SPINDLE
Clean the ABS sensor before installing. Install the ABS sensor bolt. Tighten with 8 Nm. Install the sensor cable on the spring strut (B).

C21
INSTALL ANTI-ROLL BAR LINK (C) ON THE SPRING STRUT
Tighten with 50 Nm.

C22
REMOVE THE JACK




C23
INSTALL THE WHEEL

Make sure that the mounting surfaces of the brake discs and rims are clean. Lubricate the rim center guide of the hub. Use rust inhibitor, part no. 1161030-0. Install the bolts loosely. Next tighten them crosswise to 85 Nm (63 ft.lbs). When tightening with a nut driver, use torque socket 981 4031.

Lower the car.

REPLACEMENT OF THE STEERING GEAR - ADDITION TO THE PROCEDURE

The work steps described below are supplementary to the current service manual; Front end, Steering, sect. 6, 7 (6064, 70-77).

A reinforcement plate has been added on each side of the front axle beam. The plates are loosened in order to make replacement of the steering gear accessible.




REMOVE:
- the protective pan below the engine
- the jack-up plate from the front axle beam

LOOSEN THE CONTROL ARM BOLT A FEW TURNS




REMOVE THE REST OF THE BOLTS OF THE REINFORCEMENT PLATE (1 ON EACH SIDE)

Bend the plates down as shown in the picture.

The steering gear is now accessible. Continue the removal of the steering gear according to the description in the service manual.

MOUNTING
Following the mounting of:
- the reinforcement plates
- the jack-up plate
- the protective pan

bolts/nuts of the control arm are torqued to their loaded position according to work step B14-B15 of this service bulletin.

Tighten nuts/bolts to 90 Nm (67 ft.lbs).

BALL JOINT - TIE ROD, REPLACEMENT

Note!
The tie rod ball joint has a unique design for right and left side, respectively.




WHEN INSTALLING THE TIE ROD BALL JOINT, THE BALL JOINT MOUNTING TO THE WHEEL HAS TO BE TURNED AS SEEN FROM THE PICTURE.

The arrow shows the direction toward the front

In other respects the removal and installation are done according to the current service manual; Front end, Steering, sect. 6, 7 (60-64, 70-77).