Category Archives: KYB

Active Suspension

Be Pro-Active – Active Suspension

The new Citroën C5 Aircross was launched in 2017, and KYB was selected as the Original Equipment supplier for the shock absorbers. The initial reviews in the automotive press described the behaviour of the vehicle as: “an ultra-comfortable hatchback with a unique personality”, with one commentator enthusing that “even before we’d driven our first mile, the improvements in comfort and overall refinement are little short of astonishing”.

Active suspension is starting to become a reality in passenger cars, and semi-active solutions are conquering more segments of the market. Thanks to the joint development between KYB and PSA, a suspension concept based on passive shock absorbers, capable of merging high performance with competitive costs, has been developed and applied to the Aircross. Citroën is calling the system Progressive Hydraulic Cushions.

Cutaway of shock absorber with double hydraulic stopper system.

The secret of this concept is a double hydraulic stops system. The total stroke of the shock absorbers can be divided into three differentiated parts, for which the shock absorber will provide different characteristics. The first part corresponds to the position around the center of the stroke. In this working area the conventional valving in the piston and the base valve provide the damping forces. The second and third parts correspond to the positions close to the end of the rebound and the compression strokes, with the hydraulic compression and rebound stops responsible for providing additional energy absorption.

This split allows the shock absorbers’ main valves to provide comfort and allows the hydraulic stops to take responsibility when more demanding situations are encountered. In order to achieve this effectively, both the rebound and compression stops have to be able to provide sufficient energy absorption and to have a very flexible response. The stops provide an unprecedented comfort level, and give what Citroën describes as a ‘flying carpet effect’, as the car feels like it’s flying over bumps and holes in the road.

KYB Europe’s General Manager for Aftermarket Product Management, Jean François Huan, explains: “This is another great example of the pioneering research and development that our OE engineers are famous for. I look forward to seeing how this new technology develops in the aftermarket”.

The challenges faced by KYB during the development of this double hydraulic stop system were reportedly huge. One important point was to keep the main damping law of the shock absorber invariable by the components that are part of the hydraulic stops. This goal was achieved by hydraulic and FEA calculations, and was verified by driving tests.

Another key requirement was to design the different components with sufficient robustness, in order that they withstand the high demands of the vehicle, even in the worst conditions. To be able to achieve this objective, KYB studied different material options and several geometries before reaching the optimal solution. Naturally, all components had to be built with the highest precision.

The working principle for the rebound stop is based on a reinforced plastic segment that is placed in the inner tube of the shock absorber through a deformation that defines the working area of the hydraulic rebound stop. When the rebound washer contacts the segment, a new oil chamber is created, meaning the oil is only capable of getting out of the chamber through the aperture of the segment. This controlled flow generates a hydraulic force that can be tuned with the adjustment of the segment opening. Additionally, the working area of this hydraulic stop can be tuned by changing the inner tube deformation length.

For the hydraulic compression stop, a similar principle is used. A new oil chamber is created by the interaction of a polymer component placed in the shock absorber piston and a metallic tube press fitted in the base valve assembly. The polymer part is built with some slots for the oil passage, which will allow tuning the efforts provided by the system. In order to achieve the desired maximum effort, a pre-compressed additional valve is placed in the base valve sub- assembly. The installation of the hydraulic compression stop enables the car manufacturer to simplify other suspension components, such as the compression bumper, as well as to redefine some structural parts, because of the lower efforts that will be transmitted to the vehicle chassis.

KYB was able to develop a system that combines robustness with a wide tuning range, which provides the vehicle with a soft damping when comfort is demanded and with excellent handling when control is needed. It is important to highlight that these features are met with a passive system, which assures an excellent response time and a competitive cost, according to the company. KYB is applying the double hydraulic stop system in other forthcoming vehicles in the European market – for instance the Citroën C4 Cactus – so keep an eye out!

How to Replace the Rear Shocks on a Peugeot Partner

Shocking Results: How to Replace the Rear Shocks on a Peugeot Partner

KYB provides a walk-through of how to replace the rear shock absorbers on two van models: Citroen Berlingo and Peugeot 5008/Partner.

This fitting guide runs through the process for replacing rear shock absorbers on: Citroen Berlingo/Berlingo Multispace (04/2008 onwards), Peugeot Partner/Partner Tepee (04/2008 onwards) and Peugeot 5008 (06/2009 to 11/2013). There are just fewer than 300,000 of these vehicle models on the road in the UK. The estimated fitting time for front shock absorber replacement is up to 90 minutes per side.

Remove the spare tyre. For the Peugeot 5008, you can find the special access tool just below the lip of the boot wall.

Remove the protection shields and rubber straps from the axle.

On the right hand side, remove the heat shield above the exhaust, to give access to the coil spring. Use a compressor to remove the coil spring.

On the left hand side, use a handheld compressor to compress the coil spring, in order to remove it from the vehicle. Remove the bolts on the mounting plate above the shock absorber.

Remove the bottom bolt, then remove the shock absorber and mounting plate.

Remove the mounting plate from the shock absorber.

Attach the mounting plate to the top of the new shock absorber.

Ensure the alignment is at 90 ̊.

Reattach the shock absorber and mounting plate to the vehicle. Replace the coil springs and heat shield, followed by the axle protection shield and rubber straps. Finally, replace the spare tyre. KYB recommends that shock absorbers and coil springs are always fitted in axle pairs.



“Why are some KYB shocks shorter than OE?”

This is due to the presence of a “rebound spring”. During the first mass production phase of a car, OE struts will often contain a rebound spring. It is at this point that the KYB aftermarket shocks are released, exactly matching this initial design.

After the initial mass production phase, some vehicle manufacturers are known to remove the rebound spring to reduce cost. This means when comparing a new OE unit with a KYB unit, there will be a noticeable distance in piston rod length- sometimes by up to 50mm. This can also be the case when comparing a KYB unit with a cheaper brand unit which does not contain a performance enhancing rebound spring.

It is worth noting the length of the piston has no effect on the ride height of the vehicle, this is determined by the height of the spring seat.

“What does a rebound spring do?”

It is a metal spring placed around the base of the piston rod inside the body of the shock absorber. The purpose of the rebound spring is to protect against potential damage from full extension of the piston rod. This also adds stability on cornering, and adds extra resistance during moments of heightened body roll, increasing comfort and safety.

The presence of the rebound spring makes it almost impossible to manually fully extend the piston rod from out of the body of the shock absorber. This is why there is a noticeable difference between units with and those without.

“When transfering the compressed coil spring and mounting kit to the new strut, the threaded stud doesn’t come through far enough”

On some applications, it is necessary to raise the axle or suspension slightly to attach the shock absorber mountings. This can be done either with a drive on ramp or by raising the lower control arm / axle so that it is not fully extended.

There are also tools on the market to assist with fitting shock absorbers that have a rebound spring. They compress the internal rebound spring sufficiently to be able to extend the piston rod to the required length to be able to thread the upper nut correctly.



When you replace the strut mount, you must check the shape of the piston rod. KYB shock absorbers 339031/32 have a flat surface and the strut mount must reflect this. These flat surfaces lock the piston rod in the installation position, allowing you to tighten or remove the nut. So, if you use the wrong strut mount, you are not able to assemble the parts correctly.

KYB shock absorbers 339031/32

New European Website for KYB

KYB Europe has launched a new, modern, multi-lingual website.

The new website is designed to make it easy for distributors, technicians and motorists to find any information they need quickly and easily. With much improved functionality, the website has a user friendly format, is fully optimised for mobile devices and is packed with information.

Over recent years, KYB has focused on creating a range of support tools for technicians. These are now all accessible from a central support zone which includes access to 360 degree product images, an extensive library of fitting videos, part specific technical information and technical bulletins.  Distributors still have access to the interactive catalogue powered by TecDoc. A safety page is written for the motorist, to explain the various suspension components and their vital role on the safety of the vehicle.

KYB Europe Marketing Manager, Jordan Day, explains “I am excited that this new website will support our customers at all levels to access the wide range of tools we have developed to make their jobs easier, ultimately improving their efficiency”.

Plans are already underway for future industry-leading support tools which will be added online in due course.

KYB Sponsorship Agreement with FIA WRX Team

KYB Corporation has announced that it has entered into a sponsorship agreement with FIA World Rallycross Championship Team EKS from June 2017.

The Audi S1 EKS RX Quattro is using KYB’s electronic power steering (EPS) which is widely coveted in motorsports. The KYB logo is visible on both the EKS racecar and service truck. EKS is made up of Toomas “Topi” Heikkinen and EKS owner Mattias Ekstrom.

Swedish driver Mattias Ekstrom won the championship in 2016. The two-time DTM champion grew up with rallycross and spent a large part of his youth in RX paddocks. The team EKS is a celebration of everything that Mattias loves about racing; the passion, enthusiasm and joy. He is currently 3rd in the championship, with 143 points.

Finnish driver Topi started racing at the age of 8 and switched to rallycross in 2010, winning the Finnish Championship in his first season. He became Global Rallycross Champion and also a two times X Games gold medalist. In 2014, Topi finished runner-up in the World RX Drivers’ Championship. He is currently 11th in the championship with 58 points.

EKS has been competing in the WRX since 2014. In the 2016 season, EKS won the Team Championship, raising hopes for the team’s future prospects. KYB has been providing the team with EPS since 2015 and continues to provide technical support alongside the new sponsorship agreement.

Rallycross consists of 12 two day events across the world, on tracks that are a mix of rallying and circuit racing. Drivers are equipped with RX Supercars with over 600bhp and the ability to accelerate from 0-60mph in less than two seconds. In 2014, WRX attracted 11.4 million European viewers watching the dedicated coverage across all 12 rounds. Keep an eye on KYB’s social media pages for regular updates on the EKS team.

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).


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


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).


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


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).


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).

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).

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).


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.

KYB – Inside Suspension

KYB – Inside Suspension


Showing how suspension is working inside the car, and which part is doing the hardest work during each manoeuvre.

Worn mounting kits – characteristics and visual signs

Have you ever replaced a shock absorber and put the old suspension mounting kit back on? If you were brave enough to admit it, you will be pleased to know you are not the only person!

Just like a shock absorber, a suspension mounting kit is pushed and pulled 1,500 times every mile – over the course of 50,000 miles that means this small but important component has moved 75 million times. Imagine how that amount of work will deteriorate the components in the mounting.

Suspension mounting kits optimise suspension and steering performance by:

a) Acting as a pivot for the steering mechanism, providing a smooth steering response;
b) Reducing squeaks, rattles and vibration noise.
Worn mountings have an adverse effect on ride control and safety. Mount wear depends on the type of travel, driving characteristics and the individual vehicle, however a good guideline is that if the struts are worn out, the mounts will probably be worn out too. Strut mounts should therefore be replaced every time you replace struts.

Characteristics of a worn mounting kit

* Clunking noises
* Vibration
* Loose or stiff steering
* Poor alignment
* Tyre wear
Visual signs of a worn mounting kit

* Cracked and/or sagging rubber
* Corrosio
* Deformed or bent parts
* Pitted rubber

Suspension mounting kits improve vehicle handling, ride control, alignment, braking and steering. They should be replaced every time you replace a vehicle’s shock absorbers.

Garage and sales training

KYB UK – a leading supplier of shock absorbers, coil springs and suspension mounting kits – provides valuable technical training for its garage customers. The company’s training
programme for technicians advises them on what to look out for when checking for worn shock absorbers and springs on a car

Sue Clough, Customer Service Manager, KYB UK, says: “Our training programme helps garages to look for physical signs of wear on shocks and springs, as well as the symptoms they would feel driving a vehicle. Training sessions are normally held at an individual garage customer’s premises or given to a group of garages at a
central location.

“In addition we supply visual aids, including leaflets and point-of-sale material which garages can use to explain to motorists the importance of checking shocks and springs as they are safety critical components. Their replacement also represents a great sales opportunity for our independent garage customers.”

Shocks and springs – key winter checks

As a critical item on the MOT tester’s checklist, KYB recommends that every vehicle that comes into the workshop during (and after) the winter months is checked for broken coil springs as a matter of course.

The majority of drivers will not even realise when they have a broken spring on their vehicle.

Rapid corrosion

During harsh weather conditions, any road spring can ultimately break. Grit thrown up from the road hits the coil springs and can damage the surface coating. This means that the metal becomes exposed and it therefore rapidly corrodes, especially when there is salt on the roads. In addition to this, debris which collects on the spring pan acts as a grinding paste between the spring and spring seat.

Even though a coil spring may appear to be in perfect condition when viewed in-situ with the shock absorber, the coil which is in contact with the shock absorber itself may have suffered from extensive corrosion, making it liable to breakage at any time.

The ongoing trend to reduce the shape and size of coil springs versus the continuing increase in vehicle weight is also a contributing factor to the increase in coil spring breakages. Drivers demand more optional extras, such as air conditioning and sound systems – but this additional weight puts more strain on the spring. High strength steels have been introduced, which are capable of working at higher stress levels, however even with a good surface coating on the spring, the harsh conditions on the roads in the winter mean that they are still susceptible at this time of year.

What if the spring needs replacing?

If the inspection of the coil spring highlights a breakage, resulting in a replacement being required, why not take the opportunity to check the shock absorber, suspension mounting kit and protection kit at the same time?

Shock absorber and coil spring manufacturers always talk about the importance of fitting shocks and springs in pairs – the reason for this being that shock absorbers wear gradually over time. If one is identified as leaking and worn, it’s most likely that the other one is too, as there is no significant difference between the wear rates on each side. However, if oil isn’t pouring out, the second one is not recommended for replacement. If a shock is worn, it is no longer keeping the tyre in contact with the road – which is dangerous. It also leaves the car imbalanced.

Coil springs should be replaced at the same time as this in order to maintain an even ride height on the vehicle. They also return the vehicle to the correct ride height, as they can become coil-bound over time – this is essentially losing their ‘bounce back-ability’.

The most effective way for the vehicle owner to understand this issue when it comes to their vehicle service is to explain to them the importance of fitting a pair. To help back this up, manufacturers all have a range of point of sale material – such as posters and leaflets – that garages can use in their MOT viewing area or reception.