Car Nissan Sunny models FB15 often becomes the choice of owners looking for a reliable and inexpensive vehicle for the city. However, even such cars eventually require attention to the suspension, especially to the elements that ensure smooth ride and handling. One of the most vulnerable points in the front suspension is front arm silent block, which is subjected to constant loads from road irregularities and body weight.
Ignoring signs of wear on rubber-metal joints can lead to unstable vehicle behavior on the road, the appearance of extraneous sounds, and even premature failure of other suspension components. Understanding how to properly diagnose and replace this element will allow you to save money on repairs at the dealer and return your car to factory drivability.
In this article we will analyze in detail the design of the lever on Nissan Sunny, features of choosing high-quality spare parts and a step-by-step replacement algorithm. You will learn what tools you will need for the job and what mistakes beginners most often make when repairing the suspension themselves.
Design and purpose of silent block on Nissan Sunny FB15
The silent block, or rubber-to-metal joint, plays a critical role in the operation of the front suspension, connecting the control arm to the car body. On the model Nissan Sunny FB15 it performs several functions at once: dampens vibrations from the road, ensures freedom of rotation of the lever when driving over uneven surfaces and keeps the suspension geometry within specified limits. Without a working element front arm starts to wobble, which negatively affects comfort and safety.
Structurally, the hinge consists of two metal bushings connected to each other by a layer of rubber or polyurethane. It is the rubber that acts as a damper, absorbing impacts. Over time, under the influence of temperature changes, reagents and mechanical loads, rubber loses its properties: it cracks, hardens, or even separates from the metal casing. In such cases silent block replacement becomes an inevitable procedure.
It is worth noting that on some modifications Sunny The lever can be supplied assembled, which simplifies the replacement process, but significantly increases the cost of repairs. However, for most owners it is more profitable and correct to replace only the worn element, if this is structurally possible without compromising the integrity of the lever.
⚠️ Attention: If the silent block is completely torn, the metal part may come into direct contact with the lever seat, which leads to its deformation and the impossibility of further operation without replacing the entire lever assembly.
Diagnosis of wear and symptoms of malfunction
You can understand that something is wrong with the suspension by a number of characteristic symptoms that become noticeable even to an inexperienced driver. The first sign is usually the appearance of dull knocks or squeaks when driving over small irregularities, especially at low speeds. These sounds are often located at the front of the car and can become louder when turning the steering wheel.
The second important sign is deterioration in controllability. The car may begin to “scour” along the road, require constant steering, or be unstable when cornering. This is due to the fact that the silent block cannot firmly fix the lever, and the suspension geometry changes while moving. You may also experience uneven tire wear, especially if the problem affects both sides or causes the wheel alignment to misalign.
For an accurate diagnosis, it is recommended to conduct a visual inspection of the suspension. Raise the car on a lift or jack and carefully inspect the rubber bushings. Look for cracks, delamination of rubber, traces of lubricant leakage (if any), or obvious displacement of the metal bushing relative to the rubber cage. Don't forget to check the lever play by shaking it with a pry bar.
- 🔊 The appearance of knocking noises when passing speed bumps
- 🚗 Unstable steering behavior on a straight line and in turns
- 👁️ Visible cracks or tears in the rubber upon visual inspection
- ⚙️ Uneven front tire tread wear
Selection of original and analog spare parts
When selecting a new part for Nissan Sunny FB15 You will be faced with the question: should you take the original or a high-quality analogue? Original silent block from the manufacturer guarantees perfect compliance with the dimensions and declared characteristics of the rubber compound. However, its cost is often too high, and its service life may be unreasonably short for our operating conditions.
The market offers many proven analogue manufacturers, such as Febest, TRW, Corteco or Lemförder. These brands often use harder rubber or polyurethane, which increases the life of the part. When choosing an analogue, it is important to pay attention to the brand’s reputation and the availability of quality certificates, since there are many fakes on the market that fail after a couple of months.
If you are planning to install polyurethane bushings, keep in mind that they are much stiffer than standard ones. This will improve handling and make the suspension more responsive, but ride comfort on poor roads may be reduced. For everyday use in the city, it is better to stick to high-quality tires that maintain a balance between comfort and durability.
- Original Nissan
- High-quality analogue (TRW, Febest)
- Polyurethane
- I will buy a lever assembly
Necessary tools and preparation for replacement
Before starting work, make sure you have all the necessary tools. To replace the silent block with Nissan Sunny You will need not only standard wrenches, but also specialized equipment for pressing out and pressing in bushings. Working without the correct tool may result in damage to the lever or the inability to install a new part.
You definitely need press or a powerful clamp with a set of mandrels of different diameters. You will also need ring wrenches and sockets of 14, 17 and 19 millimeters, as well as a wrench and ratchet. For safe operation, be sure to place the vehicle on secure stands, as working under the machine requires stability.
- 🛠️ Hydraulic press or set of clamps with mandrels
- 🔧 Set of keys and sockets (14, 17, 19 mm)
- ⚒️ Prybar and chisel for removing old rubber
- 🧼Brake cleaner and lubricant for installing new bushings
⚠️ Attention: Do not try to press in a new silent block with a hammer or sledgehammer, as this is almost guaranteed to damage the rubber part and disrupt the geometry of the bushing.
☑️ Preparation for replacing the silent block
Step-by-step instructions for replacing the silent block
The replacement process begins with dismantling the lever. Remove the wheel, unscrew the bolt securing the lever to the steering knuckle and the bolts securing the lever to the subframe. It is important not to unscrew the bolts completely at once, but only to loosen them so that the lever remains taut until the load is removed. After this, the lever can be removed and prepared for work on the workbench.
The next stage is removing the old silent block. If the rubber has not separated from the metal, it will have to be burned out with a torch or cut out with a chisel, being extremely careful not to damage the mounting hole in the lever. After removing the rubber, the metal sleeve can be knocked out or pressed out with a press. The seat must be thoroughly cleaned of rust and degreased.
Pressing in a new silent block requires precision. Apply a special mounting spray or soap solution to the outer surface of the rubber, but avoid getting oil on the rubber. Place the part in the lever and use a press to gently push it in until it stops. Make sure that the bushing is strictly perpendicular to the lever and is not distorted.
How to press out an old silent block without a press?
If you don't have access to a hydraulic press, you can use two long studs, nuts, and a thick metal plate with a hole. Assemble the structure so that the nuts press on the metal holder of the old bushing, pushing it out. This is a labor-intensive method that requires a lot of time and manual strength, but it eliminates the need for expensive equipment.
⚠️ Attention: When pressing, make sure that the rubber part does not twist. Even a slight misalignment will cause the silent block to quickly fail under load.
| Parameter | Original (Nissan) | Analog (Febest) | Polyurethane (CST) |
|---|---|---|---|
| Material | Rubber | Reinforced rubber | Polyurethane |
| Service life (approximate) | 60-80 thousand km | 80-100 thousand km | 100+ thousand km |
| Hardness | Soft | Average | High |
| Cost | High | Average | Average |
Correct pressing without distortions and the use of assembly lubricant are the key to long service life of the new silent block.
Lever installation and final settings
After installing the new silent blocks, you can begin installing the lever on the car. This is due to the fact that rubber bushings work to twist, and if they are tightened while suspended, the rubber will be constantly twisted.
Lower the car to the ground, making sure it is level on a level surface. Then firmly tighten all arm mounting bolts to manufacturer specifications. Typically the tightening torque is approx. 100-120 Nm for mounting bolts to the subframe, but it is better to check the exact data in the service book of your model.
After completing the mechanical work, it is highly recommended to visit the wheel alignment stand. Replacing silent blocks inevitably changes the suspension geometry, and without adjusting the wheel alignment angles, you risk quickly “eating” the new tires and losing controllability. This is a mandatory step that cannot be skipped.
Before tightening the control arm bolts on the ground, have a helper rock the vehicle up and down several times to allow the rubber bushings to settle into their natural position under the weight of the vehicle.
Typical repair mistakes and their consequences
Many drivers make the mistake of trying to save on tools or replacing only one silent block. If one joint is worn out, it is highly likely that the second one, or even the lever as a whole, is also worn out. Replacing only one part will lead to the fact that after a short time you will have to disassemble the suspension again, since the difference in the stiffness of the bushings will create an uneven load.
Another common mistake is using the wrong lubricants. Some craftsmen use regular motor oil or grease for pressing, which can lead to corrosion of the rubber. Use only special mounting pastes or soap solutions that do not harm polymers. It is also unacceptable to use sealants that can change the seating geometry.
Ignoring bolt torque is also dangerous. Tightening too weak will lead to play and knocking, and too strong can strip the threads or deform the lever. Always use a torque wrench and check the tightening 500-1000 km after repair.
Is it possible to replace the silent block without removing the lever?
Theoretically, this is possible if there is access to the press directly on the car and enough room to maneuver. However, in practice this is extremely inconvenient, dangerous and often leads to damage to other suspension components. Removing the lever is the most correct and safest option.
Questions and answers (FAQ)
How long does it take to replace a front arm bushing?
If you have the necessary tools and work experience, replacing one silent block takes from 1.5 to 2.5 hours. If you are doing this for the first time and have to press out the old rubber by hand, the time may increase to 3-4 hours on one side.
Is it necessary to change the entire lever if the silent block is worn out?
Not necessarily. On Nissan Sunny FB15 the lever often allows you to replace only the rubber bushing. However, if the lever seat is damaged (broken, deformed), then replacing only the silent block will be ineffective and the entire lever assembly will need to be replaced.
Is it possible to drive with a cracked silent block?
For a short time - yes, but only to the nearest service. Long-term operation with cracks leads to destruction of the bushing, disruption of wheel alignment and possible separation of the lever during a sharp maneuver or hitting an obstacle. This poses a direct security threat.
What tool is needed for pressing?
The ideal option is a hydraulic press with a set of mandrels. In garage conditions, you can use a powerful clamp with homemade adapters or specialized pullers for silent blocks, which are often suitable for different car models.
Does replacing the silent block affect wheel alignment?
Yes, it definitely has an effect. Any intervention in the suspension geometry, including replacement of rubber-metal joints, requires subsequent adjustment of the wheel alignment angles on the wheel alignment stand.