front suspension system 103

FRONT SUSPENSION SYSTEM - I

STRUCTURE

Objectives

Special Tools Required

Precautions

Removal of Front Suspension Components

Strut

Dismantling

Inspection of Strut

Assembly of Strut

Summing Up

Possible Answers to Self-check Questions

References

Glossary

FRONT SUSPENSION SYSTEM – I

This lesson teaches us how to overhaul the front suspension system, which is

installed between the wheel and the body of the car. The suspension system cushions the road shocks and makes the drive comfortable. As a rule, the front suspension system is always a bit more complicated than the rear suspension system because the front wheels have the added function to steer the vehicle.

The front suspension in the Maruti car is McPherson strut type independent suspension system, which consists of coil springs, McPherson struts, steering knuckles, stabilizer bar, and the front suspension control arms shown in Fig. 7.1. The suspension assembly is the same on the left and the right side front wheels and thus the procedures for dismounting, dismantling, inspection and assembly that we will study for one side of the system in this lesson are exactly applicable on the other side.

The spring compressor and the brake drum remover with sliding hammer are used for removing the front suspension components. These special tools should be used with due precaution and care to avoid any injury.

Fig. 7.1: Front suspension (a) McPherson strut with spring. (b) Steering knuckle.

(c) Stabilizer bar. (d) Front suspension control arm.

Objectives

After going through this lesson, you will be able to:

i. Remove the components of the front suspension system ii. Dismantle, inspect, and re-assemble the McPherson strut


i. Spring compressor ii. Brake drum remover iii. Sliding hammer

Precautions

Spring compressor and sliding hammer both require due care in use as both can cause injury if not used properly.

i. Tighten both nuts of the spring compressor simultaneously and equally so that the spring is compressed evenly; otherwise it may jump out causing serious injury.

ii. Take care while handling sliding hammer that your hand or fingers do not come in between the stop and sliding weight otherwise your fingers will be badly hurt

Removal of Front Suspension Components

Before the front suspension system can be removed, the car should be on

safety stands with the road wheels removed.

The stabilizer bar is first removed from the front suspension control arms.

Remove the split pin from the castle nut which holds the stabilizer bar in the suspension control arms, with pliers.

Unscrew the castle nut with a No 17 ring spanner and remove the castle nut and the washer.

The castle nut from the other side is removed similarly.

Remove the stabilizer bar mount bracket bolts from the front cross member with a No 14 socket and ratchet handle.

Remove the two brackets and pull out the stabilizer bar from the front end of the car.

Remove the split pin from the drive shaft and unscrew the castle nut with a No 30 ring spanner.

Unscrew the caliper bolts with a No 14 ring spanner and remove the caliper from the brake disc.

Remove the E-ring from the flexible brake hose mounted on the strut bracket and remove the brake hose from the strut bracket.

Hang the caliper with a wire hook.

Fix the hub puller to the hub with two wheel nuts and pull out the hub with a sliding hammer.

Remove the split pin from the tie rod-end castle nut and unscrew the nut with a No 17 ring spanner.

Remove the tie rod-end from the knuckle with the help of a tie rod-end remover.

Unscrew the nuts of the two strut bracket bolts with a No 17 ring spanner.

Remove the bolt holding the suspension control arm ball joint stud from the steering knuckle with a No 17 socket and ratchet handle.

Push out the bolts from the strut bracket with a plastic hammer.

Pull out the steering knuckle from the strut.

Remove the drive shaft from the hub and the suspension control arm from the knuckle.

Remove the strut support nuts above the body of the car with a No 12 socket and ratchet handle.

Remove the strut assembly from under the body of the car.

Fig. 7.2: (a) Stabilizer bar mount bracket. (b) Caliper.

Fig. 7.3: (a) Tie rod and knuckle. (b) Strut bracket bolts.

Strut Bracket Bolts

Unscrew the suspension control arm mounting bolt with a No 17 ring spanner and remove the suspension control arm. Strike it with a hammer, if required.

Self-check Questions

1. Where is the front suspension system installed? 2. Name the type of front suspension system used. 3. Name its main components. 4. Name the special tools required. 5. What precautions will you observe while using the special tools? 6. What No. size is the wheel nut?

We will now dismantle, inspect, and re-assemble the parts of the front suspension system one by one. First we will study the procedure for the McPherson strut in this lesson. Procedure for the remaining parts will be studied in the next lesson.

Strut

Dismantling

The strut is cleaned and placed on a table before dismantling.

Compress the coil spring with a spring compressor.

Both the coil spring compressor bolts should be tightened alternately, otherwise, the tool might slip out of the spring. Tool bolts can be tightened with a 22 mm spanner. When the tension in the spring is released, the No 17 strut nut is unscrewed with the help of a socket wrench and ratchet handle and all the parts are removed one by one. The parts, as shown in Fig. 7.4, are removed in the following order:

i. Strut inner support ii. Strut support iii. Strut bearing seat iv. Bearing dust seal v. Strut bearing vi. Strut spring upper seat vii. Strut spring seat.

Remove the strut from the still compressed spring.

Remove the bump stopper from the strut assembly.

The dismantled parts include the strut nut, lock washer, strut inner support, strut rebound stopper, strut support, strut mount, strut mount seat, strut bearing seat, bearing dust seal, strut bearing, strut spring upper seat, and strut spring seat.

Inspection of Strut

Push and pull the damper rod to see that there is a resistance to its movement.

Check that there are no scratches on the damper rod.

Check the lower mount bracket holes for damage or cracks.

Check the strut damper seal for any leakage.

The coil spring and all the other parts such as the strut nut, lock washer, inner support, rebound stopper, strut support, strut mount, strut mount seat, strut bearing seat, strut bearing, bearing dust seal, spring upper seat, strut spring seat, and the bump stopper should also be inspected and replaced with a new one if deterioration or damage is discovered.

Assembly of Strut

Take the already compressed coil spring and place the spring end properly on the stepped part of the lower seat of the strut.

Fig. 7.4: Components of the strut.

Strut Assembly

Strut Inner Support Strut Bearing Seat

Strut Bearing

Strut Bearing Upper Seat

Pull the strut rod as far up as possible and take care that the rod does not retract into the strut.

Push the bump stopper on the strut rod to the bottom.

Pull the strut rod upwards again as it may have gone down when pushing the bump stopper over it.

Install the rubber spring seat in such a way that its stepped portion matches with the coil spring upper end.

Install the spring upper seat matching its step over the rubber seat.

Install the cleaned strut bearing on the spring upper seat and apply SERVOGEM 3 grease on the bearing.

Install the bearing seat and the bearing dust seal.

Install the strut mount seat, strut mount, strut support, strut rebound stopper, strut inner support, plain washer, lock washer, and the strut nut.

Tighten the nut with a No 17 socket wrench to the specified torque.

Apply water proofing coating, that is, paint or lacquer on the strut nut and the threaded portion of the strut rod after tightening the nut.

Hold the strut assembly vertically in a bench vice and loosen the spring compressor with an extension and ratchet handle.

Both the bolts should be loosened simultaneously to avoid slipping.

Check the coil spring again for proper seating in its stepped seats.

The procedure discussed here is for a single strut assembly. The other strut assembly is assembled in a similar manner.


7. Why is strut bearing required? 8. How is the hydraulic damper checked? 9. Which grease is used on the strut bearing?

Summing Up

In this lesson we studied how to remove the front suspension system components. For this, when the car is lifted off the ground, one should know where to place the jack so that the vehicle does not get damaged and remains stable when lifted off the ground. Similarly, one must be careful to not get hurt while using the sliding hammer. Likewise, it should be ensured that the spring compressor holds the springs properly so that they don’t come off. Such and other precautions ensure that the job gets done quickly and safely.


1. between the wheel and the body of the car 2. McPherson strut type independent suspension system 3. coil springs, McPherson struts, steering knuckles, stabilizer bar, and the front

suspension control arms 4. spring compressor and the brake drum remover with sliding hammer 5. See section 7.2 6. No 30 7. Since the strut rotates when the wheel is steered, bearing has to be provided

for easy movement 8. Push and pull the damper rod to see that there is a resistance to its

movement 9. Servogem 3

References

1. Maruti 800 Service Manual

Glossary

Bump stopper A rubber or urethane piece of special construction to limit

upward suspension travel.

Caliper The U-shaped housing that contains the hydraulic pistons and holds the pads on disc brake applications.

Castle nut A hexagonal nut provided with slots at the top to insert locking pin to lock the nut with bolt & prevent from loosening.

Control arm Suspension component which connects the steering knuckle to the body of the car.

E-ring E-shaped clamp ring used to hold the brake pipe in place.

McPherson strut A type of front suspension with the shock absorber and coil spring in one unit that rotates when the wheels are turned. The assembly mounts to the vehicle body at the top and to one ball joint and control arm at the lower end. It is named for its inventor, Earle s. McPherson.

Sliding hammer A tool to be used with brake drum remover to remove brake drums out of axle spindle.

Split pin A locking pin of steel which is split length wise from one end. After inserting through the hole its split end is

opened and turned outward to prevent the nut from loosening.

Stabilizer bar A hardened steel bar connected to the frame and both lower control arms to prevent excessive body roll. Also called an anti-sway or anti-roll bar

Steering knuckle Inner portion of the spindle that pivots on the king pin or ball joints.

Strut damper Hydraulic damper included with the McPherson strut.

Suspension Parts or linkages by which the wheels are attached to the frame or body of a vehicle. These parts or linkages support the vehicle and keep the wheels in proper alignment

FRONT SUSPENSION SYSTEM - II

STRUCTURE

Objectives


Wheel Hub and Brake Disc

Dismantling

Inspection

Assembly

Wheel Bearing and Steering Knuckle

Dismantling

Inspection

Assembly

Control Arm

Dismantling

Inspection

Assembly

Stabilizer Bar

Inspection

Installation on Car

Control Arm

Strut Assembly

Steering Knuckle


Caliper

Other Components


References

Glossary

FRONT SUSPENSION SYSTEM – II

In the previous lesson, we learnt how to remove the components of the front

suspension system and dismantled, inspected, and assembled the McPherson strut. In this lesson, we will study the dismantling, inspection, and assembly of the remaining components namely, wheel hub and brake disc, wheel bearing and steering knuckle, control arm, and stabilizer bar. Finally we will install the system components in the car.

Objectives


i. Overhaul the front suspension system


1. Control arm bush remover 2. Control arm bush installer


Dismantling

We will first detach the wheel hub from the brake disc.

Unscrew the four bolts with a No 14 socket wrench and ratchet handle.

Remove all the four bolts along with spring washers.

Tap the hub with a plastic hammer and detach the wheel hub from the brake disc.

Place the hub on a bench vice and push the bolt back with a drift punch or a steel rod and hammer to remove the wheel bolts from the hub.

All the other bolts are removed in a similar manner and may have to be

replaced if their threads are damaged.

The wheel bolt is installed by turning the hub upside down and pushing the bolt in its hole by striking with a hammer. The installation can also be done on a hydraulic press.

Inspection

Check the hub bearing seat for wear.

The hub bearing seat can be checked for wear by measuring the diameter of the hub spindle or by installing a new ball bearing on the spindle. If it appears loose on the hub, the hub should be replaced with a new one.

Inspect the threads of the wheel bolts. If the threads are damaged, replace the bolts.

Inspect the hub splines for wear.

Check the brake disc for wear or scoring. If the disc is badly scored or has deep lines, it should be replaced.

Assembly

Place the hub on the brake disc in its seat properly and screw in the four bolts.

Tighten the bolts evenly and crosswise with a No 14 socket to the specified torque.

Wheel Bearing and Steering Knuckle

Dismantling

Remove the wheel bearing with a drift punch or a steel rod.

Strike the bearing with a steel rod and a hammer from inside to remove the bearing. The oil seal and the spacer are also removed along with the bearing.

Fig. 8.1: Wheel hub and brake disk.

Inspection

Check the ball bearing for smooth running and side play.

When the bearing is spun by hand, there should be no rattling noise. If the bearing produces a sound or sticks when spun, it should be replaced with a new one. An excessively worn ball bearing which has excessive side play should also be replaced.

Check the spacer for wear at its faces.

The knuckle is turned over and the other bearing is removed in the same manner. Both bearings are of the same size.

Check the bearing bores on both sides in the steering knuckle for wear.

Check the ball joint stud hole and threaded hole of stud locking bolt.

Check the tie rod-end taper hole for wear or distortion.

If the tie rod-end taper hole is excessively worn or distorted, the knuckle should be replaced.

The other steering knuckle is checked in the same manner.

Assembly

Press the outer ball bearing in the knuckle and apply SERVOGEM 3 grease on the ball bearing cage.

Install the spacer and then install the inner ball bearing by striking with a hammer and bearing installer.

Install a new oil seal, keeping its lip towards the outside and by striking with a plastic hammer at the periphery.

Control Arm

Dismantling

The next step is to remove the control arm bushing with the help of a hydraulic press and a bush remover.

Place a hollow cylinder under the control arm bush hole and put the bush remover over the bush and press it gradually.

Inspection

Inspect the arm and the ball joint stud for wear or damage after removing the bush.

Check the ball joint for smoothness of operation.

If the ball joint is loose, the control arm as a whole should be replaced because the ball joint is an integral part of the control arm.

Check the ball joint dust cover for deterioration or cracks and replace it with a new one if found damaged.

Check the control arm for bend, twist or rusting and replace it if found to be bent, twisted or badly rusted.

Assembly

Place the control arm on a hydraulic press on a flat surface.

Apply soap water on the arm bush and put it on the control arm hole.

Press the bush with the help of an installer and press gradually.

Stabilizer Bar

Inspection

The stabilizer bar is first inspected for bend or twist and damage at the

threaded portion.

Check the four stabilizer bar rubber bushes and the two mount bushes for deterioration.

Check the two mounting brackets for rusting or damage. If any component is found damaged, it should be replaced with a new one.

Self-check Questions 1. How is the ball bearing checked? 2. Which grease is used?

Installation on Car

Control Arm

Smear some grease on control arm mounting bracket in the car and also on the bush sides.

Place the bush end of the arm in the mounting bracket in the body of the car.

Screw in the arm bolt in the threaded hole in the body of the car through the control arm bushing.

Tighten the bolt up to the specified torque, keeping the control arm at an angle of 10 ± 5O from the horizontal.

Strut Assembly

Install the strut assembly under the body of the car, inserting the two studs of the strut support in the holes and hold it there.

Screw in the nuts of No 12 size along with spring washers and tighten them to the specified torque.

Steering Knuckle

Apply grease to the ball joint stud, the spindle hole in the steering knuckle, and the splines on the axle spindle.

Insert the spindle and the control arm ball joint stud in their respective holes in the knuckle.

Place the upper part of the knuckle in the strut bracket.

Insert the two mounting bolts from the front side.

Tighten the nuts with a No 14 socket to the specified torque.

Set the ball joint stud properly and clamp it with the No 14 bolt passing through the stud groove in the knuckle and tighten it to the specified torque.

Insert the tie-rod in the steering knuckle hole and tighten the castle nut with a No 17 ring spanner.

Insert a split pin in the tie rod-end hole through castle nut and bend it properly.


Install the wheel hub along with the brake disc on the drive shaft spindle and set it properly, pushing the hub inward by hand pressure.

Push the drive shaft out through the wheel hub so that the spindle projects out from the hub.

Install a plain washer and tighten the castle nut with a No 30 ring spanner and then up to the specified torque.

Tighten the brake disc bolts with a No 14 socket to the specified torque.

The foot brake-pedal should be kept pressed during this time so that the hub does not rotate.

Insert a split pin in the castle nut through the spindle hole and bend it properly.

Caliper

Spread the friction pads with a screw driver or a lever and push the caliper over the brake disc.

Fix the caliper to the knuckle with two bolts and tighten them with a No 17 socket and ratchet handle or a ring spanner.

Other Components

Install a rubber bush at each end of the stabilizer bar and insert the stabilizer bar in the control arms from the front side.

Install one rubber bush on the rear side of each control arm keeping the conical end of the bush on the inside.

Install one large plain washer and castle nut on one side and tighten the nut with a No 17 ring spanner and then to the specified torque.

Insert a split pin through the castle nut and bend it properly.

The castle nut on the other side should be tightened similarly and a split pin should be installed to prevent it from getting loose.

Install the front mounting rubber bushes over the stabilizer bar and then the two mounting brackets on the front cross member.

Screw in the four bracket bolts and tighten them with No 14 socket and ratchet handle.

Fit the E- ring in the brake hose on its mounting bracket.

This finishes the procedure of removal and installation of the front suspension system. The wheels can now be installed and the car lowered on the ground.


3. What is the angle of the control arm from the horizontal? 4. What should we do while tightening the brake disc bolts? 5. How are castle nuts prevented from getting loose?


1. When the bearing is spun by hand, there should be no rattling noise. If the

bearing produces a sound or sticks when spun, it should be replaced with a new one. An excessively worn ball bearing which has excessive side play should also be replaced.

2. SERVOGEM 3 3. 10 ± 5O 4. The foot brake-pedal should be kept pressed so that the hub does not rotate 5. split pin is installed through the hole in the stud and the nut to prevent it from

getting loose

References


Glossary

Ball joint A flexible joint having a ball-and-socket type of construction

used in suspension systems.

Brake disc Steel disc connected to the wheel hub and which is clamped between the brake pads to slow down or stop the wheel.

Caliper The U-shaped housing that contains the hydraulic pistons and holds the pads in disc brake applications.

Control arm Suspension component which connects the steering knuckle to

the body of the car.

Drift punch A tapered tool used to center a component in a bolt hole prior

to installing the bolt.

Hydraulic press A mechanical device used for removing / assembling tight

fitting components. Its ram operates by increasing or decreasing the hydraulic pressure.

Knuckle Connection between the control arm and wheel hub by which

the wheel is turned.

Oil seal A round shape rubber component with sealing lip to stop any oil leakage along the shaft.

Ratchet handle Special handle used with socket wrench. Its ratchet

mechanism helps in tightening/loosening of the bolts without taking out the socket wrench from the bolt head or nut.

Scoring Scratch marks which develop in the brake drum or disc

surface.

Spacer Metallic or non metallic distance piece for making up the gap between two faces.

Stabilizer bar A hardened steel bar connected to the frame and both lower control arms to prevent excessive body roll. Also called an antisway or antiroll bar.

Stud A short rod with threads on both ends.

Wheel hub A rim shaped metallic drum on which the tyre is mounted.

REAR SUSPENSION SYSTEM

STRUCTURE

Objectives


Disassembly

Inspection

Installation

Summing Up


References

Glossary

REAR SUSPENSION SYSTEM

In the previous lesson we studied the procedure of overhauling the front suspension system. We saw that the front suspension is of the independent type in which each wheel moves up or down independent of the other one. The front wheels also need to be steered at the will of the driver and hence, the suspension system components are such that they can be moved from side to side.

This lesson covers the rear suspension system, which is vastly different from

the front suspension system. The rear suspension is of the dead axle type, that is, it does not transmit drive to the wheels and it consists of leaf springs, bump stoppers, and shock absorbers. The rear suspension system used in the Maruti 800 car is of the conventional type in which if one wheel is disturbed and executes up or down motion, the other wheel is also tilted. This affects the stability of the car and also tends to reduce passenger comfort. Thus, many passenger cars these days provide independent suspension systems at the front and also at the rear.

Objectives


i. Overhaul the rear suspension system.


i. Wheel spanner ii. Brake drum remover and sliding hammer

Disassembly The procedure for dismounting is started by removing the road wheel first.

Fig. 9.1: (a) Wheel nuts and wheel spanner. (b) Spindle cap.

Loosen the four No 19 wheel nuts with a wheel spanner.

Remove the spindle cap.

Lift the car with a hydraulic jack.

Remove the four wheel nuts.

Remove the wheel.

Place a safety stand properly and lower the jack.

Remove the split pin.

Unscrew the castle nut with a No 30 socket and handle.

Fix the drum remover to the wheel drum with the help of two nuts and pull with

a sliding hammer until the drum comes out.

Unscrew the brake pipe flare nut from the wheel cylinder.

Remove the bleeding nipple cap attached to the wheel cylinder and install it on the end of the brake pipe to prevent the brake fluid from flowing out.

Remove the E-ring holding the brake pipe to the bracket on the axle.

Unscrew the nut and remove the brake pipe.

Remove the brake pipe on the other side from the bracket.

Unscrew the four nuts which hold the rear brake back plate to the axle and remove the back plate.

Unscrew the upper bolt of the shock absorber with a No 17 socket and handle.

Fig. 9.3: Sliding hammer.

Fig. 9.2: (a) Split pin and castle nut. (b) Brake drum and drum remover.

Unscrew the lower bolt and remove the shock absorber from the car.

Place the hydraulic jack under the axle and lift the jack so that the axle is supported on it.

Unscrew the four U-bolt nuts and remove the two U-bolts and the bump stopper.

The bump stopper is a piece of rubber of special design and prevents the axle

from banging against the car’s underside when the car goes over a big bump at high speed.

Unscrew the nut at the leaf spring front eye and remove the bolt.

Unscrew the two shackle nuts and remove the shackle plate.

Remove the leaf spring and place it on ground.

Lower the jack and lift out the axle after removing the U-bolts, the bump stopper and the leaf spring on the other side.

The parts of the suspension system removed here include the leaf spring bolt,

U-bolt, bump stopper, axle, leaf spring, shock absorber upper bolt, shackle plate, and the hydraulic damper, commonly known as the shock absorber. These would be in pairs after the system has been disassembled on both sides.

The rear axle carries the two rear road wheels and also carries a part of the weight of the vehicle. It is a dead axle and does not transmit drive to the wheels.

Self-check Questions 1. What is the size of the spindle nut? 2. What is the function of the bump stopper?

Fig. 9.4: (a) Bleeding nipple and back plate. (b) E-ring.

Fig. 9.5: Bump stopper and U-bolts.

Inspection

The rear shock absorber is inspected first.

Pull and push the two ends of the shock absorber. The shock absorber should offer resistance to the movement. If the ends move freely towards or away from each other, it indicates that the shock absorber is not functioning well.

Inspect the tubes for deformation or damage and the bushing for wear or damage.

Inspect the lower bushing for damage and replace any part which is defective.

Inspect the shock absorber for any evidence of oil leakage.

Inspect the upper bolt and the shackle pin threads for damage.

The leaf springs are inspected next.

Inspect the leaf spring for cracks and any other damage. The leaf should be in a perfect arc and not bent or deformed at any place.

Inspect the bushes for wear and breakage. Replace them if necessary.

Inspect the bump stopper. The portion of the bump stopper that is made of rubber should not be damaged, otherwise, it should be replaced. It should also be ensured that the bump stopper sits properly on the leaf spring.

Inspect the U-bolt threads for damage.

Inspect the axle spindle for wear on bearing journals and check the threads of the spindle for damage.

Inspect the spring seat for damage.

The pin of the spring sits in the hole on the axle and locates the leaf spring properly so that it does not move forward or backward. The projection in the bump stopper plate sits in the leaf spring similarly.

Inspect the shock absorber for damage.

Inspect the front end bushing of the leaf spring.

The bearings are then removed from the hub for inspection.

Keep the wheel drum on two iron plates and push out the bearing with the help of a steel rod and hammer.

Place the drum up side down and push out the other bearing from the drum.

Inspect the bore in the drum where the bearing fits for wear.

If the bore in the drum where the bearing fits is worn, the bearing becomes loose in the bore. The other bore should similarly be checked for wear.

Inspect the threads of the wheel studs for damage.

If the threads of the wheel studs are found to be damaged, they have to be removed for replacement by exerting pressure from the side with a steel rod and a hydraulic press.

The spacer that fits between the bearings cannot be placed in the reverse direction, that is, the smaller size bore should always be outwards and the larger size bore inwards in accordance with the taper of the spindle.

Inspect both the bearings visually for proper fitting of seal on one side.

Spin the bearings to see they do not make a rattling noise or exhibit sticking. There should be no excessive side play in the bearings.

Fill the cage with grease and insert the bearing so that the sealed side is towards the inner side of the drum.

Install the bearing in the bore with a bearing installer and hammer.

Place the spacer so that its smaller end is outwards.

The cavity in the drum is then filled upto 40% of the space with grease to ensure that the bearings are supplied with a reserve stock of grease.

Install the outer bearing so that its sealed side faces towards the outside of the car body.

Strike the bearing with a rod until it sits properly in the bore in the wheel drum.

Installation

Apply silicone grease by spreading it properly into a thin coat over the entire area of the eye of the spring leaf.

The silicone grease does not damage rubber parts and prevents abnormal

noise which may arise during driving if the bushes are dry.

Install the bushes.

Push in the tubular piece of steel pipe in the bushes.

Grease is applied and the bushes installed in the other eye of the spring leaf in a similar fashion.

Apply grease in the hole of the bracket in the car and press in the bushes.

Place the front end of the spring in the bracket and fix it with a No 17 bolt and nut, keeping the nut toward the outer side.

Hold the bolt head with a ring spanner to prevent its rotation and tighten the nut to the specified torque.

Apply grease to the pins of the shackle and fix the leaf spring with the help of the shackle to the car.

Install the angle plate over the pins on the other side, place the washers and tighten the nuts.

Place the axle under the leaf springs, taking care to see that the pins projecting on the underside of the leaves fit in the depressions on the axle spring seat.

Lift the hydraulic jack-prop under the axle to keep the axle in place.

Place the bump stopper in its proper place and insert the two U-bolts over the plate of the bump stopper.

Screw in the nuts and tighten them to the specified torque.

Fix the brake pipe in the bracket hole in the axle.

Insert the E-ring and fit it in place.

Clamp the brake pipe on the other bracket.

Fit the two bushes in the upper eye of the shock absorber.

Insert the hollow tubular piece in the bushes taking care to see that it is centrally placed.

Fix the single bush at the other end and insert the tubular piece.

Insert the bolt through the box-channel in the car and place the upper eye of the shock absorber in front of the bolt so that the bolt passes through it.

Place the lower eye of the shock absorber in the bracket and insert the bolt at the end.

Screw in a nut at each end and tighten the nuts to the specified torque.

Insert the studs of the brake back plate in the axle flange holes and screw in the nuts with hand.

Tighten the nuts.

Connect the metallic brake pipe at either end and tighten the flare nuts fully.

Screw in the bleeding nipple in its proper place.

Clamp the brake pipe to the axle bracket.

Remove the bleeding nipple cap.

Connect the metallic brake pipe and tighten the flare nuts fully.

Push the drum onto the axle spindle.

Place the washer and screw in the castle nut.

Tighten the nut with a No 22 socket to the specified torque.

Insert the split pin and bend it properly.

Install the spindle cap and tap it lightly to fix it properly.

Mount the wheel and screw in the wheel nuts.

Lower the safety stands and remove them from under the car.

Lower the jack and pull it out.

Tighten the wheel nuts to the specified torque.


3. How is the shock absorber inspected?

Summing Up

In this and the previous lesson, we studied the suspension systems which are used at the front and at the rear in a Maruti 800 car. The suspension system is a part of the running system.


1. No. 30

2. The bump stopper is a piece of rubber of special design and prevents the axle from banging against the car’s underside when the car goes over a big bump at high speed.

3. Pull and push the two ends of the shock absorber. The shock absorber should offer resistance to the movement. If the ends move freely towards or away from each other, it indicates that the shock absorber is not functioning well.

References


Glossary

Bump stopper A rubber or urethane stop to limit upward suspension travel. Also called a bump stop.

Castle nut A hexagonal nut provided with slots at the top to fix locking pin through opposite slots to lock the nut with bolt and prevent it from loosening.

Dead axle Axle which only supports the weight of the car and does not transmit power to the wheels.

Drum remover U-clamp shaped tool which is fixed to the brake drum and pulled to remove the drum from the axle spindle.

E-ring E-shaped clamp ring used to hold the brake pipe in place.

Eye Circular hole at the end of the master leaf of the leaf spring by which it is bolted to the frame or body of the car.

Independent suspension A suspension system that allows a wheel to move up and down without affecting the opposite side wheel.

Leaf spring A spring assembly made of several pieces of flat spring steel strips which are bolted and clamped together.

Safety stand An equipment / fixture / stand on which the engine removed from car is placed for dismantling or assembling.

Shackle plate A mounting that allows the end of a leaf spring to move forward and backward as the spring moves up

and down during normal operation of the suspension.

Shock absorber A device used to control spring movement in the suspension system.

Sliding hammer A tool to be used with brake drum remover to remove brake drums out of axle spindle.

Split pin A locking pin of steel which is split length wise from one end. After inserting through the hole its split end is opened and turned outward to prevent the nut from loosening.

U-bolt A U-shaped clamping bolt with both ends threaded.

Wheel drum A rim shaped metallic drum on which the wheel is mounted.

Wheel spanner A socket type spanner with L-shaped arm to give leverage for opening / tightening the wheel bolts.

front suspension system 103

Documents

suspension components

suspension assembly

rear suspension system

suspension control arms

castle nut

strut bracket

sliding hammer

c stabilizer bar