Wise Auto Tools: Along with other makes, I've worked on BMW's at Carmax, when I worked first as a reconditioning tech and then later as a retail tech. To beat the book time, I used an air chisel sometimes to help remove old control arm and trailing arm bushings without removing the arms completely from the car. You have to be really careful not to damage the new bushings when installing them. There's also a risk of marring the surface that the bushings press into, especially when using a crude method like an air chisel! It can be done, however there are much better tools available today. Read on for information on BMW bushings and how to change them.
Control arms and trailing arms play a significant role in the ride quality of BMW and Mini Coopers. These parts are designed to control suspension geometry and isolate passengers from noise, vibration, and harshness caused by rough road surfaces. Control arms are made of strong aluminum or steel, while the bushings inside them are usually made of rubber. Over time, these rubber bushings can deteriorate, leading to uneven tire wear, excessive NVH (Noise, Vibration, Harshness) or off-center steering. Replacing the rubber bushings when they worn out or torn, they should be replaced in pairs. If one control arm has worn-out bushings, the other control arm's bushings are likely to follow suit.
Some manufacturer's use hydraulic bushings that can leak hydraulic fluid and make noise over time, which is another reason why it's a good idea to service both side control bushings at the same time. On a side note, motors mounts sometimes use hydraulic fluid also. When inspecting control arm bushings, it's important to know how the bushing should appear when new and to be aware of the different types of bushings installed on vehicles that share the same platform. Some appear to have gaps, however that could be as designed because not all bushings are completely solid. Look for obvious leaks if it's the type that have hydraulic fluid in them, or dry rot and cracking. Some flex is normal but using a pry bar to help inspect is a good idea. Sometimes prying a little can reveal a tear. I used to get a trusted tech to power brake, putting into the forward and reverse while I looked for excessive movement in motor mounts.
Question - Are suspension and control arm bushings a common problem on BMW's?
Suspension and control arm and trailing arm bushings are a common problem on BMWs, especially after they have a few years of age on them. BMWs have a reputation for being a performance-oriented vehicle, and their suspension components are designed to handle some aggressive driving and poor road conditions while still delivering a nice ride. Even drivers that have no mechanical knowledge say that there's a certain "feel" that BMW's have over other comparable vehicles. However, since the driver cannot "feel" the sometimes harsh road conditions, they may not even realize the stress that they are inflicting on their suspension. This can sometimes lead to accelerated wear and tear on suspension bushings. As I've mentioned, control arm bushings and trailing arm bushings, can be a problem with BMWs. The bushings are responsible for isolating the passengers from NVH and controlling suspension geometry. As the bushings wear, the suspension can become misaligned, resulting in uneven tire wear, poor handling, and a harsh ride. When the bushings fail, they can also cause knocking or clunking noises.
BMW uses several different bushing designs, including rubber, polyurethane, and hydraulic bushings. Rubber bushings are the most common type and are prone to wear over time. Polyurethane bushings are more durable than rubber but can transmit more noise and vibration. Hydraulic bushings are used on some BMW models and are known for their smooth operation and long life. It's important to follow-up control arm and bushing service with an All wheel alignment.
Question - Do BMW's feel different when braking compared to Domestic cars?
BMW vehicles are known for their unique driving experience, which can feel different compared to domestic cars. I always thought that they seemed to squat when braking, but that's just me. BMW's reputation for sporty performance and precision handling means that their vehicles are engineered to provide a more engaging driving experience than many domestic cars. BMW's suspension and braking systems are designed to provide a firmer, more responsive feel. The suspension is typically stiffer and more aggressive than that of domestic cars, which can result in a sportier driving experience with more precise handling. The braking system is also designed to provide a more immediate response, with firmer pedal feel and what feels like more stopping power. Additionally, BMW's steering systems are engineered to provide more direct and responsive feedback than domestic cars. The steering is typically more precise and communicative, allowing drivers to feel more connected to the road. In my experience, BMW owners are typically more willing than some others, to pay for service to maintain the unique feel and handling of these vehicles.
Question - Are Mini Coopers made by BMW?
Yes, Mini Coopers are made by BMW. In 1994, BMW acquired the rights to the Mini brand and subsequently launched the new Mini Cooper in 2001. Since then, BMW has continued to manufacture and develop the Mini Cooper lineup, which has grown to include several different models, such as the Cooper, Clubman, Countryman, and Convertible. As a result of BMW's involvement, the modern Mini Cooper features BMW's signature engineering and design elements, including a focus on performance and precision handling. BMW has also incorporated advanced technology and safety features into the Mini Cooper, such as advanced driver assistance systems and infotainment options. The Mini Cooper is a result of BMW's extensive experience and expertise in engineering and designing high-performance vehicles. The partnership between BMW and Mini has allowed for the development of a unique and successful lineup of vehicles that combines the iconic style of the original Mini with modern engineering and technology.
Question - Are there any special tools that allow changing the control arm bushings out on a BMW without removing them completely?
Yes, there are special tools available that can allow for the replacement of control arm bushings on a BMW without removing the control arms completely. These tools can be used to press the bushings out and to press the new ones back in while the arm is still partially installed on the vehicle. Some techs prefer to remove them completely. This is a matter of preference and maybe considered on a case by case basis. Some control arms may not be serviceable using these tools, and replacement of the entire control arm may be necessary.
Question - Is there a special tool for adjusting the toe on a Mini Cooper?
Yes, see the link below for more information on that tool.