BMW 35i: Front Axle Geometry & Bearing Service

Hello.

After having driven approximately 15,000 km with my new (old) Passat 35i, I noticed that the front tires are wearing down more on the inside. One would assume this is due to a misaligned axle geometry. However, I had the alignment adjusted in January, and I haven't driven particularly hard over curbs or anything like that since then. When you look at the axle from a distance, it actually seems misaligned! My question is whether this wear can occur on its own to such an extent due to worn suspension components or axle bearings, or whether the workshop might not have tightened the screws properly? The car has 210,000 km on the clock, but doesn't feel noticeably unstable, and nothing seems unusual when I shake the wheels.

Best regards,
Albrecht.

There are several possible solutions.

First of all, there are different types of tires, such as these Firestone Firehawk 7xx tires, which repeatedly show signs of wear on Golfs and Passats. My dad acquired a set with exactly this combination last spring. The tires were almost new, and the alignment, camber, etc., were precisely adjusted upon acquisition. However, after 20,000 km, significant signs of wear appeared on the inner tread surfaces. I can rule out incorrect settings because a friend did the adjustment, and he wouldn't do shoddy work within our circle of friends. Regarding the quality and wear, I think this has been discussed many times in forums here and elsewhere.

Secondly, there are configuration issues due to incompetence. ATU is a reliable candidate in this regard; I've read about it multiple times and witnessed firsthand what's going on.

You can roughly check it yourself using a level, plumb bob, etc. There was a thread about this here before...

Hi there,
If only one tire is worn unevenly, it indicates an issue with the camber. If both tires are worn unevenly, it suggests a problem with the alignment or a component that affects the alignment.
The most likely culprits are the tie rod ends; you'll only notice something when they're completely worn out by feeling for play while shaking the wheels. Otherwise, check them for play by trying to move them precisely perpendicular to the joint axis. If this is possible, definitely replace them (and have the alignment adjusted...). Damaged ball joints are more likely to cause issues with the camber, and it's less probable that both would exhibit the same amount of play simultaneously.
Otherwise, I recall that there were different values for the front axle geometry on the 32B depending on the suspension system installed; however, I cannot assess how this would affect things if you pulled the data from the computer for the wrong suspension setup.

Regards,
Olli.

Hello,

First of all, thank you for the tips. With the Passat 35i, there's also the "Plus" suspension (which the 81 kW diesel engine also has) and the standard suspension. The adjustment instructions are usually divided based on an 85 kW rating. Therefore, errors are almost guaranteed when making adjustments. What surprises me is that if you compare the camber between the front and rear axles (fixed), I've noticed over time that my front axle tends to develop a more negative camber. So, freshly adjusted: camber in the front is less than the camber in the rear; after 15,000 km, the camber in the front is greater than the camber in the rear. This difference is at least 2-3 degrees. Where could this be coming from?
The tires are size 205/45 R16 Toyo Proxes (likely very soft), and both of them are wearing out on the inside.

Best regards,
Albrecht.

Hi there,
If I understand correctly, the wheels are wider apart at the top than at the bottom (negative camber), or was it exactly the opposite?
Anyway, there aren't that many steering components. At the top, the most likely culprits are the shock absorber mounts, which are probably worn out after a certain mileage (unless they were already replaced when the shocks were changed). That could explain the effect. At the bottom, it's the control arm, which is connected to the front axle carrier via rubber-metal bushings towards the engine and has the ball joint facing the wheel.
Both components can wear out. In addition to a visual inspection and functional test of the mentioned parts, it would be most helpful to try moving the shock absorber while the vehicle is on a lift. This should allow you to see any play or looseness.
However, a sudden change in direction will also shift the track, which should be evident from the measurement log.

Regards,

Olli.

Hello,

I had a similar problem with my Passat three years ago. The symptoms were the same as yours: the inner edges of the front tires were completely worn down, while the outer edges were still okay. It turned out that the tie rod ends were worn out. I replaced them, and it's been quiet ever since.

Best regards.
Christoph.

Hello,

For your information: I just went to a shaking table at Dekra. They checked the issue (for free). It's the inner joints of the tie rods (located on the steering gear). This can cause the alignment to change . They are very easy to replace; I did it myself about half a year ago on my old Passat, which is now in Poland .
However, despite having driven over 60,000 km, he never experienced any problems with tires coming off the rim, which suggests that the brand probably does play a role!
Thank you for the tips.

Best regards,