The steering wheel shakes while driving, and there is a strange noise from the chassis

A Nissan NV200 entered the store, and the owner said that the steering wheel always shakes while driving. As long as they release their hand, the car will run to one side, and they can also hear the creaking sound of the chassis. They suspect that the screw on the right front wheel tire is loose.

After listening to the car owner's description, the mechanic checked the screw on the right front wheel and found that it was fixed properly. However, the wheel looked misaligned, with the front of the wheel opening outward and the vertical angle slightly inward. At this time, the steering wheel is in the middle position. What could be the problem?

The mechanic checked the left front wheel and found it to be in the normal position, indicating that there is indeed a problem with the right front wheel. Sitting in the car and shaking the steering wheel, one can hear a sound coming from the chassis, which is from the position of the right front wheel. This situation is very abnormal and needs to be lifted up to check the chassis.

When the mechanic saw the problem with the chassis, he was very surprised. He didn't expect that the problem was on the subframe. As shown by the arrow in the picture below, there was a very obvious crack in the fixed position of the lower support arm on the subframe, which is a very rare situation.

We observe from the bottom, as shown in the figure below, this position of the subframe is about to break. If it breaks, it means that there is a problem with the support of the right front wheel, which may pull out the half axle. At that time, waiting for the bus will definitely cause it to collapse.

After learning about this situation, the car owner was extremely angry. He didn't expect that there would be a problem with the position of the subframe. The key is that the car has never had an accident. How could this be?

The mechanic explained that it is likely due to the poor road conditions during normal driving, which are quite bumpy. By observing the location of the cracks in the subframe, it can be seen that the cracks have existed for a long time, but now the cracks have become larger and are not enough to support the lower support arm to maintain a normal state.

This subframe is made of steel material, and the anti rust paint on the surface has fallen off a lot, showing a lot of rust, as shown in the following picture.

How should this problem be solved? Can it be welded well? Car owner problem master. The master said that welding is not possible and a new subframe is needed. After replacing the subframe, four-wheel alignment is also required.

After the car owner agreed, the mechanic removed the subframe, as shown in the picture below. This is its subframe, which is a half frame type subframe.

Looking at the damaged position of the subframe, where the lower support arm rubber sleeve is installed, we can analyze the cause of the damage: scratches, rust, and abnormal road impact have occurred, causing cracks to grow larger and eventually unable to support the lower support arm.

Look at the back of the subframe, there is a large area of rust.

After removing the subframe, the steering gear and stabilizer bar are also installed on the subframe.

This repair case reminds us that if our car experiences abnormal situations while driving, which are different from normal driving, we must promptly have a professional mechanic inspect and eliminate risks.