Frequently Asked Questions
Q1: How can I tell whether the BMW G38 rear right strut is already damaged?
Common signs of damage include: a dull "thumping" noise when the right rear wheel goes over speed bumps, the right rear body side being noticeably lower than the left, noticeable rear-end squat to the lower right side during acceleration, and stronger bumpiness on the right rear side than the left. A simple self-check method: after stopping the vehicle, press down firmly on the right rear fender and release quickly. If the body bounces up and down more than twice before stopping, the damping on the right side has significantly degraded.
Q2: Are the G38 rear right and rear left struts interchangeable?
No, they are not interchangeable. Although similar in appearance, the left and right rear struts on the G38 differ in internal damping valve calibration to accommodate left-right load differences. Forcibly swapping them will result in different rebound rhythms on both sides of the rear axle when going over speed bumps, affecting driving stability.
Q3: After replacing the rear right strut, is it necessary to also replace the rear left strut?
Replacing in pairs is not mandatory; the right side can be replaced alone. However, if the left side strut has been in service for a long time (over 70,000 km or 5+ years), it is recommended to replace both sides as a pair. Otherwise, you may experience inconsistent rear-end rebound when going over speed bumps and increased rear-seat rocking.
Q4: After replacing the strut, the instrument panel shows a "Chassis Function Restricted" warning, but the vehicle drives normally. What is the cause?
This situation is usually not a problem with the strut itself, but rather the air suspension system has not been reset after installation. After replacing rear suspension components, a diagnostic tool is required to perform "height calibration" and "component matching" on the air suspension system. It is recommended to connect a diagnostic tool after installation, clear the fault codes, and perform rear axle height initialization.
Q5: What accessories are recommended to replace at the same time as the rear right strut?
It is recommended to replace the following accessories simultaneously: the rear strut dust boot, the upper bump stop, and the top nut securing the piston rod. In addition, check the right rear stabilizer bar link ball joint for looseness and check the rear axle height sensor link for integrity.
Q6: After replacing the strut, the rear right suspension feels stiffer or bumpier than before. Is this normal?
Yes, this is normal. Over long-term use, the damping oil inside the old strut gradually degrades and damping force decreases. After the new strut restores the original factory damping level, rear seat passengers may feel more fine vibrations. Typically, after driving 300-500 km, the strut will gradually break in to a stable condition.
Q7: There is a "creaking" or "squeaking" noise from the right rear wheel area while driving after strut replacement. What is the cause?
This type of noise requires careful diagnosis. Common causes include: the top nut of the strut is not tightened to the specified torque, the dust boot is not installed properly, the right rear stabilizer bar link ball joint is aged, or wiring harness is pinched during installation. It is recommended to remove the right rear wheel and check all installation positions.
Q8: Is a wheel alignment (chassis angle calibration) necessary after replacing the G38 rear right strut?
Rear axle alignment is recommended. The G38 chassis rear suspension is a multi-link design. Removing the strut involves disconnecting the lower control arm from the subframe, which may affect rear wheel toe and camber after installation. It is recommended to drive 30-50 km after replacement to allow the suspension to settle naturally before performing a rear wheel alignment.
Q9: Are the G38 rear strut and front strut interchangeable?
Absolutely not. The rear and front struts have fundamental differences in body length, piston rod diameter, mounting method, and damping valve tuning. Forcing interchangeability will result in chassis dynamic imbalance and seriously affect driving stability and comfort.
Q10: Is the G38 rear right strut suitable for the later generation G68 long wheelbase 5 Series?
No, it is not suitable. The G68 is the next-generation long wheelbase 5 Series launched in 2024, with a completely different chassis structure, suspension geometry, and strut mounting dimensions. Parts are not interchangeable with the G38.
