Category Archives: Tyres & Wheels

Under Pressure: The Importance of Tyre Inflation

Under Pressure: The Importance of Tyre Inflation

Having the correct tyre pressure is important for numerous reasons. From tyre lifespan, to safety and fuel economy, having too much or too little air in your tyres can have wide-ranging implications.

In May, the MOT test in England, Scotland and Wales changed, and several new items to be tested were added, including checking if tyres are obviously underinflated. As well as this now being required by law, it might also be an opportunity to build trust with your customers by advising them of the issues with having under – or over – inflated tyres.

With fuel prices on the increase, you can advise customers that through having correctly-inflated tyres they can save money, in terms of fuel economy. Some 3% more fuel is used if the tyre inflation level is 6psi below what it should be.

TyreSafe, the UK charity dedicated to raising awareness of the importance of correct tyre maintenance and the dangers of defective and illegal tyres, estimates that under-inflated tyres cost UK consumers £600m per year. By regularly checking tyre pressures and making sure they are at 100% of the manufacturer-recommended psi, the lifespan of the tyres is maximised, which also saves money.

Under-inflated and defective tyres are the primary cause of most road traffic accidents. When tyres are not correctly inflated, braking performance is affected, which can lead to dangerous situations. Alarmingly however, over a third of tyres are being driven on roads at least 8psi below vehicle manufacturer recommendations.

Although it may seem obvious, it is important to remember that the air in a vehicle’s tyres carries the majority of the vehicle’s load, and tyres are the only contact point between the car and the road.

This ‘contact patch’ of an inflated tyre is only the size of the palm of your hand, so to have the best possible stability, this area needs to be flat to the road, which is achieved by having the correct tyre pressure.

Here are four tyre inflation scenarios:

■ When tyres are inflated to 100%, pressure is distributed evenly, meaning the tyre will achieve the maximum possible mileage and lifespan, and the vehicle will display optimum road handling and fuel consumption.

■ If tyres are only inflated to 60%, there will be extreme flexing in the rubber, leading to excessive heat build-up and presenting a major safety risk. In this scenario, tyre mileage is very low, at around 35%.

■ When people think of tyres not being inflated correctly, they tend to think of under-inflation, however, over-inflated tyres also present problems. For example, if tyres are over-inflated to 120%, there will be greater wear in the tread centre, leading to reduced mileage – around 10% lower than if the tyres were inflated at 100%.

■ The fourth and most common scenario is where a vehicle’s tyres are not quite fully inflated. When inflated to 80%, there is greater stress in the tyre shoulder, leading to a smaller contact area, which means reduced mileage of around three quarters of the optimum rate, and greater fuel consumption.

As well as it now being a requirement of the MOT to check if tyres are obviously under- inflated, mechanics can also build trust by advising customers of the benefits of regularly checking pressure, including greater safety, extended tyre lifespan, and savings on fuel consumption.

FAG Wheel bearings – Generation 2.1 Repair

FAG Wheel bearings – Generation 2.1 Repair

FAG wheel bearings offer plenty of advantages, as you would expect from the ORIGINAL manufacturer. This video shows a Gen.2.1 wheel bearing replacement highlighting the importance of the snap ring plus hints, tips and best practice when it comes to removal and replacement.
FAG – Quality and Innovation since 1883.

FAG Wheel Bearing Repair Solution vs. OES repair

FAG Wheel Bearing Repair Solution vs. OES repair

The FAG Wheel Bearing Repair Solution allows garages to save significant time when replacing or repairing the wheel bearing of a light commercial vehicle. The reason: You only have to replace the actual wheel bearing and not the active axle housing – as usually done. See for yourself when compared to OES repair.

Front Shock Fitment: Alfa Romeo

Step by step replacement guide for 01.11 Mito Model

With nearly 18,000 of these models on the road in the UK, the chances that your workshop will be faced
with a shock absorber replacement are fairly high. This job should take roughly one hour per side and should be undertaken following our expert instructions.

Getting started

Remove the tyre. Now release the ABS sensor cable from it’s clip, then the brake hose (see Fig 1).

Undo the clip on the left and keep it safely stored (see Fig 2).

fig3

Then undo the brake hose clip (see Fig 3).

fig33

Raise the height of the vehicle then remove the bottom two bolts from the strut (see Fig 4).

fig 4

Strut assembly

Under the bonnet, remove both windscreen wipers and the scuttle panel (see Fig 5).

fig5

Loosen the top nut and, whilst supporting the strut below, remove the nut and lift out the strut assembly (see Fig 6).

fig6

Use a good quality coil spring compressor to safely disassemble the unit.When assembling the new KYB shock absorber, coil spring, protection kit and top mount, check the end of the coil spring is aligned at the correct point on the spring seat (see Fig 7).

fig7

Gripping stuff

Ensure you tighten the top mount to the correct torque. It’s essential that you never use mole grips to steady the piston rod whilst assembling the unit – the grip can damage the smooth chrome coating on
the piston rod which will result in it not having perfect contact with the oil seal, causing premature leaking (see Fig 8).

fig8
The assembled suspension unit can now be offered up under the wheel arch and fixed in position from the top first, tightened to the correct torque. Use a small jack to support the wheel hub weight (see Fig 9).

fig9
Lower the vehicle and finish tightening the top nut to the correct torque. Then you can replace the bulk head, windscreen wipers and scuttle panel, not forgetting the small clip to the side of the bottom bracket see Fig 10).

fig10

Always fit in pairs!

KYB advises that you check the wheel alignment after the shock absorber is fitted to the vehicle and that shock absorbers and coil springs are always fitted in pairs.

Types of Coil Spring

Cylindrical

A cylindrical spring normally consists of end coils, transition coils and spring coils. A cylindrical spring can be designed to provide a linear rate, or equally designed to give a progressive spring rate by varying the pitch. One advantage with cylindrical springs is that they can be automatically handled easily during production.

Cylindrical Spring

Cylindrical springs can also, in the axial direction, be bent in shape. This variant can be of interest when the designer needs to compensate for lateral forces influencing the shock absorber.

axial

Conical

The conical spring is normally chosen when there is limited space for the springs in a suspension system. This type has today mostly open ends and sometimes one pig tail end. The spring can be designed with either linear or progressive spring rate. Should the designer wish to achieve a linear rate, this is achieved by changing the pitch in accordance with the spring diameter to hold the spring rate constant throughout the deflection. The designer would increase the pitch as the spring diameter increases.

Conical Spring

Mini-block

A real mini-block spring design has coil diameters adjusted so that most of the coils fit inside each other when the spring is compressed to a short length, hence the name mini-block.

This design solution can reduce the bloc length close to two times the material diameter. The advantage is the very small bloc length of the spring hence space is saved. This can be of value in the rear of a car when, for example, a flat loading area is required.

It is important to note that the fitting of the coils inside each other is controlled by the diameter of the coils, and is not dependant on the type of material used (tapered or parallel).  For this design, tapered material is sometimes used which gives a weight saving benefit, but against this is the increased risk of premature end coil failure:  A more detailed explanation of this is available from our technical brochure.

Mini-bloc springs can be designed to have progressive or linear load and deflection characteristics, and this can be achieved through the use of either tapered or parallel wire.  They often have a linear rate however since the reduced material diameter compensates for the reduction in the springs external diameter.

For this design Kilen always use parallel wire; fulfilling the mini-bloc requirements and achieving the load and deflection characteristics whilst ensuring springs that are not prone to premature end coil failure.

Mini-block Spring
Kilen produce the World’s largest range of coil springs for the automotive aftermarket
The Complete Spring Supplier

An Insight into Rolling Bearing Dynamics

An Insight into Rolling Bearing Dynamics

CABA3D is our view into the dynamic interior of rolling bearings. This software makes it possible for us to analyze and understand the internal operation of bearings. This understanding forms the basis for the development of reliable and energy-efficient rolling bearings.

Front wheel bearing replacement – ‘Next Generation’ Ford Transit

The Ford Transit has been around since 1953 but this early Transit was rarely seen in the UK. The Ford Transit we have come to love was introduced in 1965 and was known by many as the Mark 1. With over 6,000,000 vehicles built since its introduction we have all seen them in our workshops. In this article we are going to look at changing the front wheel bearing on a Next Generation Transit which was launched in 2000 and ran until 2006; although the current Transit is very similar.

This particular Transit was a rear wheel drive model however, the procedure for changing the bearing on front wheel drive models is very similar. The manufacturer’s recommended repair time of 0.9 hours is easily achieved with the help of this guide from FAG.

A four-post ramp was used to change the wheel bearing in this example however, a good two-post ramp or axle stands could just as easily be used. The only special tools required are a torque wrench and a suitable press. The old bearing will also have to be pulled off the hub with the use of a special puller (Ford part number 15-092 and 15-091). After determining which bearing is to be replaced, safely raise the wheel off the ground and remove. The brake caliper is removed next. To do this gently squeeze the piston back slightly and then undo the two securing bolts.

Carefully place the caliper clear to one side, taking care not to put strain on the brake hose (see picture below).

Remove the split pin and castellated pressing from the centre hub nut and then undo the nut and remove the washer. On the rear wheel drive models the splined shaft is very short; the purpose of the shaft is to allow for a phonic ring for the ABS sensor (see picture below) and this can easily be removed from the hub by using a copper hammer to gently drift it out. On front wheel drive models the drive shaft will have to be completely removed from the hub.

To do this separate the hub carrier from the lower suspension arm and then with the aid of a copper hammer gently drift the driveshaft out. Next the five torx bolts securing the hub to the carrier will have to be removed. To do this align the holes in the brake disc to the bolts securing the hub to the hub carrier (pictured below) and then with a 50 torx socket and extension remove the bolts (a good quality torx socket is recommended, if the heads of the bolt get rounded off it will be extremely difficult to remove them due to their position and they will have to be drilled out).

The hub assembly can now be removed – it may be necessary to gently prise the hub from the back (pictured below). Separate the brake disc from the hub assembly.

Remove the bearing
The bearing can now be removed from the hub. To do this, attach the special tool to the top of the bearing and then wind the bearing off the hub. In this example we made our own
tool from an old bearing with a strong steel pipe securely welded in the centre (pictured below).

Then with a press we pushed the bearing off (the bearing will fit either way up so make a note of the fitting position of the old one first). The inner race of the bearing will then have to be removed from the hub. Because there is nowhere to attach a puller securely, tap the bearing needle roller bearing and cage off and then with a die grinder carefully cut part way through the inner race just enough to weaken it, taking care not to damage the hub (pictured below) – then gently tap the race off.

Note: using a blunt air chisel is a nice controlled way of removing the inner race without causing damage.

Making sure the bearing assembly is the correct way round, push the bearing back on to the hub with the press by applying pressure to the inner race (pictured below).

Note: check the length of the new bearing assembly against the old one as there are two different lengths.

Clean the contact surface between the hub and the disc. The brake disc can now be refitted to the hub. Clean the hub locating hole on the hub carrier. Whilst holding the hub in place take care to align the holes then secure the hub with the new bolts provided, tightening them evenly and sequentialy to the manufacturer’s 53Nm. On rear wheel drive models the splined shaft can now be reinserted.

On front wheel drive models re-fit the drive shaft and re-attach the hub carrier to the lower suspension arm. Fit the new retaining washer and nut but don’t tighten fully just yet. Next the brake calliper is refitted and the bolts tightened to 175Nm (because the brake calliper has been removed it is advisable to pump the brake pedal a couple of times to allow the piston to return to its operational position). Re-fit the front wheel and then lower the vehicle back to the ground.

The hub nut can now be tightened in two stages:
Stage 1 – tighten the nut to 250Nm;
Stage 2 – rotate the hub several times then tighten to 420Nm.

Check the hub now turns freely and fit the castellated pressing and new split pin in place.

Front wheel bearing replacement – Toyota Corolla

First introduced back in 1966 the Toyota Corolla has been with us for a massive 60 years, and incredibly, according to Toyota, one Corolla is sold on average every 40 seconds worldwide! The Corolla has been massively popular in the UK which is mainly due to its high reliability record and reputation for quality. These factors make it a popular purchase for familes and taxi drivers for example.

The 8th generation Corolla (E110) was introduced in 1995 and since then 62,878 models have been sold in the UK until production was stopped in 2002. In this article we are going to look at how to replace the front wheel bearing on the Corolla, and give you some handy hints and tips to help you on your way.

The type of bearing used on the Corolla can be a little tricky to fit because it has to be pressed into the hub and onto the flange, and during this process if its done incorrectly you can damage the bearing prematurely. But don’t worry because the bearing experts at FAG are here to help with this useful guide.

Firstly check to see if the vehicle has alloy wheels fitted, if it has it may be fitted with antitheft bolts so you’ll need to find the key. Raise the vehicle on a ramp (although the job could be done on the ground if necessary) and remove the wheel on the relevant side. Undo the three bolts securing the bottom suspension arm and release it. Undo the bolts (see pic, below) securing the brake calliper to the hub.

Push the brake cylinder back (see pic, below) and slide the calliper off.

Undo the screw securing the disk to the hub and remove the brake disc. On the steering arm ball joint pull out the pin, undo the castellated nut and release the joint. Remove the hub nut pin (see pic, below), undo the nut and release the driveshaft from the hub.

Undo the two large bolts (see pic, below) holding the hub to the suspension strut and release.

Remove the hub assembly from the vehicle (see pic, below).

Using a press push out the flange from the hub. Remove the two metal rubber seals (see pic, below) and push out the large metal flange around the outside.

Once the seals have been removed you should be able to see a large circlip (see pic, below), remove this with a suitable set of circlip pliers.

With the circlip removed use the press to release the bearing from the hub. Finally use the press to extract the inner race that’s still attached the the flange. The new bearing can now be fitted.

Hub profile
Take the time to check that the hub profile is perfectly round and not damaged. The outer race of a bearing will always take the shape of the hub its being pressed into, therefore if the hub has been damaged and is oval this could prematurely wear the bearing over time. its important to not put any force through the balls or rollers inside the bearing. With this in mind when you press the bearing into the hub make sure you press on the outer race, and when pressing the bearing onto a flange use the inner race. By doing this we ensure that the pressing force is not transmitted through the bearing rollers/balls, but only through the metal race.

Many types of new wheel bearing will have an ABS encode ring placed just behind the oil seal on one side of the bearing. FAG colour-code the oil seals to indicate which side has the encoder in it; generally a black seal represents the side of the bearing that contains the encoder ring. However if you are unsure we do provide some detector cards which are available from your local stockists.

And finally its worth pointing out that the clamp load is essential on these types of bearings, so make sure you use a torque wrench when tightening the hub nut or bolt. Failure to do this could lead to premature failure of the new bearing.

Fitment of the bearing is the reverse of the removal.

Front wheel bearing replacement – Mazda 3

The Mazda 3 was introduced in 2003 to replace the aging 323. Over the years it has forged itself a reputation for high reliability and quality and has now sold over 77,000 models in the UK. Now, as the manufacturer’s warranty is expiring, we are starting to see more and more coming into the aftermarket.

Premature damage
In this article we are going to look at how to replace the front wheel bearing on the Mazda 3 and give you some handy hints and tips to help you on your way. The type of bearing used on the Mazda can be a little tricky to fit because it has to be pressed into the hub and during this process, if done incorrectly, you can damage the bearing prematurely.

Firstly check to see if the vehicle has alloy wheels fitted, if it has it may be fitted with anti-theft bolts so you’ll need to find the key. Raise the vehicle on a ramp (although the job could be done on the ground if necessary) and remove the wheel on the relevant side. When possible we recommend that you replace bearings in pairs, as chances are the bearing on the opposite side could be just as worn as the one you are replacing.

Undo the large hub nut securing the driveshaft and release the shaft from the hub. Undo the two bolts (pictured below)  securing the calliper to the hub, remove the assembly and secure it out of the way.

Remove the brake disc and disconnect the ABS connector (pictured below).

Undo the lower ball joint bolt (pictured below) and release the lower arm from the hub.

Undo the nut (pictured below) securing the steering rack to the hub and release it.

Undo the bolt securing the hub to the suspension strut (pictured below) and release it from the strut.

With the hub released use a press or a puller (pictured below) to remove the flange from the hub assembly.

Remove the large circlip (pictured below) retaining the bearing into the hub and push out the bearing assembly from inside the hub.

Depending on how the bearing separates you may need to extract the inner race from the flange; a puller was used in this example to remove the race from the flange.

Check the hub
Once the bearing components have all been removed, take the time to check that the hub profile is perfectly round and not damaged. The outer race of a bearing will always take the shape of the hub its being pressed into, so if the hub has been damaged and is not perfectly round this could prematurely wear the bearing over time.

This particular bearing comes with an ABS encoder ring on one side so you need to make sure you are pressing the bearing in the right way round, otherwise the encoder side of the bearing will be facing the wrong side. The seals on an FAG bearing are normally colour coded – black is the encoder side – however if you are unsure you can always use an encoder card to check.

Press on the outer race
When you fit the bearing into the hub make sure you press on the outer race. By doing this you ensure that the pressing force is not transmitted through the balls or rollers, but only through the outer race. The same applies when pressing the flange into the bearing. Ensure no force is transmitted through the bearing by supporting the bearing on the inner race and pressing on the flange directly. Fitment of the remainder is the reverse of the removal.

Finally its worth pointing out that the clamp load is essential on these types of bearings, so make sure you use a torque wrench when tightening the hub nut or bolt. Failure to do this could lead to premature failure of the new bearing.

Wheel bearing replacement – Skoda Fabia

The Skoda Fabia was introduced in 1999 and was built until it was face-lifted in 2007. During this time the Fabia forged itself a reputation for high reliability and quality. The MK1 has sold over 170,000 models in the UK and as a result we are seeing a lot of these models coming into the aftermarket scene. The type of bearing used on the Fabia can be a little tricky to fit because it has to be pressed into the hub and during this process, if done incorrectly, you can damage the bearing prematurely. But don’t worry because the bearing experts at FAG will make it much easier for you with this handy guide.

Firstly, check to see if the vehicle has alloy wheels fitted, if it has it may be fitted with anti-theft bolts so you’ll need to find the key. Raise the vehicle on a ramp (although the job could be done on the ground if necessary) and remove the wheel on the relevant side. When possible we recommend that you replace bearings in pairs, as chances are the bearing on the opposite side could be just as worn as the one you are replacing.

Removing the hub
Undo the large hub nut securing the driveshaft and release the shaft from the hub. Undo the two bolts securing the calliper to the hub and remove the assembly and secure it out of the way. Remove the brake disc and the metal bracket securing the brake pipe to the hub.

Undo the lower ball joint bolt (pictured below) and release the lower arm from the hub.

Undo the nut securing the steering rack to the hub and release it. Undo the bolt securing the hub to the suspension strut (pictured below) and release it from the strut.

For easier access you can undo the anti-roll bar link attached to the suspension strut as it will enable you to manipulate the strut better.

With the hub removed the bearing can now be pressed out of the hub. In this article we are using a special tool which is able to extract the bearing from the hub and press it back in. For safety reasons it’s a good idea to reattach the lower arm if you are using the tool on the vehicle, this will ensure that the hub is more secure. Place the pressing pins into the correct five or four stud arrangement and slide the two-piece collar (pictured below) around the bearing.

Bolt the tool to the hub (pictured below) and start to tighten the tool using a socket or spanner.

This will start to pull the bearing out of the hub (pictured below).


Important checks
Once the bearing has been removed, take time to check that the hub profile is perfectly round and not damaged. The outer race of a bearing will always take the shape of the hub its being pressed into, so if the hub has been damaged and is not perfectly round this could prematurely wear the bearing over time. You will also notice that the old bearing had a locking ring around the outside which has now broken (pictured below).

This is completely normal as the new bearing will have a new clip fitted to it. But don’t forget you will need to make sure that all the remnants of the old clip are removed from the hub.

When you fit the bearing into the hub, make sure you press on the outer race and not on the flange. By doing this you ensure that the pressing force is not transmitted through the balls or rollers in the bearing but only through the outer race. In our case, we are using the tool to ensure this happens. To fit the bearing, install the collar around the new bearing and mount the pressing pins onto the ring through the holes in the flange. Offer the bearing up to the hub and bolt the assembly in place (pictured below).

The tightening of the tool will now press the bearing into the hub and you will hear a loud ‘click’ as the locking ring locates into the hub assembly. Fitment of the remainder is the reverse of the removal.