Worn Inner Tire: Causes & Solutions

To my dismay, I discovered that the rear tires on my Sharan were wearing down excessively, *only* on the inner edge, as mentioned in the title. I maintain the recommended tire pressure for this size. The explanation for wear on front tires is straightforward.

What could be the reason for the issue with the main unit (HA)? As far as I know, there are no settings that can be adjusted on it.

Hi!

I'm also at a loss because I haven't seen anything like this before.
You can start by measuring the drop.
That's all I can think of right now.

Hello,

Possibly the wheels were installed with an incorrect offset.

Best regards, Rainer.

Hi there,
What is the background story like?
Is this the first set of tires, or were previous sets okay? Is the vehicle owned by the original owner and has it been involved in any accidents?
hg
Herbert.

Okay, I'll answer your questions now.

Possibly the wheels were fitted with an incorrect offset.

No. I'm using the original 18-inch tires that came with the Sharan.

Is this the first batch that's not ripening properly, or have there been issues with previous batches as well?

I have owned the vehicle since April 2018, and as a result, I have already changed the wheel set three times (winter/summer - summer/winter - winter/summer). Therefore, this unusual wear would have already been noticeable to me. The vehicle has no accident history and is driven exclusively by me. Collisions with curbs or any other contact can be ruled out.

The mileage is 48,000 km. What surprises me is the uniform, yet improper, wear pattern on both sides at the same time .

Otherwise, I would have been able to use those tires for at least one more season.

Hi,

"The rear axle alignment on the Sharan 7N can be adjusted using an eccentric bolt. However, it shouldn't have shifted if contact with another vehicle is ruled out, as you mentioned."

"If the front tire wear pattern was incorrect and the inner edges were worn, this might not have been noticeable as long as there was still a relatively significant amount of tread depth (e.g., 4mm on the inside, 6mm on the outside. A difference of 2mm is relatively subtle). However, if the rear tires are wearing evenly, the issue may become more apparent (e.g., 1mm on the inside, 3mm on the outside. The difference is still 2mm, but immediately visible). But such significant wear in a single summer would require very extreme driving conditions."

Greetings.
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It can also be used as a verb, meaning "to gust."

From my recollection, the front wheels do not show any unusual signs of wear.

The previous Sharan didn't have any problems in this regard. Therefore, I initially rule out a design flaw. Unless, of course, something was "improved" during the production process that made it worse...

The only part of the suspension I've had to replace so far is the rubber bushing. However, I don't think that should have any effect on the rear axle in this configuration.

Okay, I'm ready. Please provide the German text you want me to translate into English.

I've noticed a few Sharans where the rear door had buckled inwards at the top. It reminded me of something I saw on older BMWs.
Even though all the Sharans I saw were loaded to their maximum capacity, that was not a typical sight for a Volkswagen. Perhaps others have noticed this as well?
haithamina

I have attached pictures from both sides. I don't think the rear wheels are particularly buckled.

Hi!

Based on the pictures, it appears there was a fairly significant and negative impact.
Also, it's symmetrical on both sides, if I take the bars of the gate as a reference point, and relatively even on both sides.

But I don't find the tire wear to be extreme.

And I also meant that you can adjust the suspension on the Sharan.

So: just measure it; there are often quite wide tolerance ranges.
You can also set or leave it at the tolerance limit.

That was Steffen's eagle eye!
What you can do:
- measure the tilt;
- Check the bearing clearance.
- Check the suspension.
hg
Herbert.

Evening.
I often noticed this at Volkswagen/Audi when I was a service advisor there.
The larger the tires became, the more wear I observed on the sidewalls, especially with heavily worn tires. The A6 models with 255-size tires were the worst; I often thought something was misaligned there. After working on the tenth vehicle, I eventually came to accept it as normal. However, I never noticed this issue with narrower tires.

Regarding your tires, I would share Steffens opinion; they don't actually look that bad .

Thank you for your responses.

First, I will inspect the axle suspension and the wheel bearings. Since the Sharan tracks perfectly straight, I will postpone any adjustments to the camber for now. However, I will try to perform a check using a laser.

I've examined the rear wheel bearings from last season more closely and have observed a similar wear pattern, although not to the same extent. Furthermore, I've been considering the rim dimensions for the Sharan.

The original wheels are 7.5 x 18 inches with an offset of 35 and are fitted with 225/45 R18 tires.
The alloy wheels are 7 inches wide with an offset of 40, and they have 205/60 R16 tires.

Since I purchased the Sharan with 24,000 kilometers and no accident history, I assume that the wear is caused by the axle geometry and not due to a defect or malfunction.

Am I correct in assuming that, overall, the center of the rear tires has more tread depth than the edges? This would be an indication of insufficient tire pressure, which can lead to increased wear on the outer edges. Combined with the wider summer tires and a camber setting close to the tolerance limit towards the "negative" side, this is quite plausible.

A narrower tire/rim combined with a smaller rim diameter can naturally compensate for this better.

Quote:

First, I will inspect the axle suspension and the wheel bearing. Since the Sharan tracks perfectly straight, I will postpone any correction of the camber for now. However, I will try to perform a check using a laser.

You could measure the drop height. For example, in 2016, a Sharan had...

Target value for rear dive: from -0°50' to -1°50', (which is equivalent to -1°20' ± 30').

Target value for total rear track: from 0° to +0°20' (which is +0°10 ± 10').

If it were my car and I could rule out all other possible causes,
I would have the vehicle professionally aligned and set the camber to approximately -1 degrees, and the total toe to 0°5' (5 minutes plus). The differences between the left and right measurements should ideally be zero.

I think that, along with the "correct air pressure," your problem will then be at least negligibly small...

Autoservice wrote:

Am I correct in saying that, overall, the center of the rear tires has more tread than the sides?

No. The tire profile is still okay. I pay very close attention to the air pressure, so that potential source of error can be ruled out.

Autoservice wrote:

I would have the vehicle professionally measured.

I am very cautious about that. My colleague just had a professional survey done with his Golf R... I would rather not do that.

A colleague also drives a Sharan of the same type and is experiencing the exact same issue. When I have some time, I will check for worn-out bearings or possible damage, and then I'll probably just learn to live with it.

Is the car additionally lowered?