[Rain]

The previous owner placed Mercedes 19" wheels on the 2007 ML350 we have and didn't upgrade the spare. Where do I start looking for one that fits? We've been putting run flats on but its getting crazy how short they live.

August of last year I put 4 standard tires on with 7/32s left on the tread. 4 months later the rears had worn down to the indicators so I placed 4 run flats on it with 9/32s treat left.
The rear 2 of those lasted till May. I again replaced the rear 2 tires with run flats (8/32s) and now they are worn down to 3/32s. That is 90 days going from good treat to the wear indicators.
I'm in need of 4 new tires now and the dealership has been repeatedly asked about the excessive wear of the rear tires. . They only state that run flats wear quickly and that Mercedes vehicles eat rear tires.

Lastly, with the slightest bump in the road, the entire rear end of our ML350 goes out of control. Again, I've had the local Mercedes Dealership check everything out and they state its all normal.

Any leads on my multi part post is appreciated -
Rain
Biloxi, MS

 

[SkippyJasper]

What is the mileage associated with the calendar timings?

It does sound like there is an alignment issue to me based on the 'jumpy' response to road bumps.

Was the vehicle ever involved in a collision?

When the dealer says 'all is normal' have they performed a 4 wheel alignment?

Do the rears wear uniformly?

Is this an air suspension or hydraulic?

Skippy

 

[Rain]

Alignment was performed at the mount/balance back in May. Ive attached a scan of the report.
Dealership said the suspension and frame looked fine.

Rears seem to wear close to even. Passenger rear maybe a bit faster.

Carfax showed no accidents with this vehicle.

118,891 miles back in May when the tires were put on (8/32s) and the alignment was performed.
125k on it today.

Forgive my ignorance of the suspension - but how do I determine if its air or hydraulic?

 

[SkippyJasper]

I believe the air suspensions (Airmatic) are height adjustable from the console. If you do not have such then they are hydraulic.
In another thread it was revealed that operating the Airmatic in sport mode (lowered) increased tire wear.
The report is useful and others with more experience will weigh in.
What was offered to correct the front caster 'out of tolerance'?

Skippy

 

[Rain]

Thanks for your help Skippy -

There is no dash controlled suspension so it must be hydraulic.

Nothing was mentioned regarding the front caster out of tolerance. They suggested an alignment with the mount/balance and they handed my wife the bill and this report.

 

[260e crusier]

The previous owner placed Mercedes 19" wheels on the 2007 ML350 we have and didn't upgrade the spare. Where do I start looking for one that fits?

What size are your current tires and spare? Spare doesn't need to be upgraded if diameters of both are about the same.

 

[Rain]

What size are your current tires and spare? Spare doesn't need to be upgraded if diameters of both are about the same.

255/50ZR19 on all 4 corners.

The dealership stated that the spare would not fit the ML350 - Spare : T155/90D18 113M

 

[moosejaw5.0]

Your spare is the same height as your regular wheels. They are both 29" tires. If it fits the hub and has the correct offset, then it is an acceptable spare.

What tire pressures due you use? You should have all the tires the same pressure unless you have a large load on the rear tires i.e. towing. The tire pressures on the vin tag (in the drivers door jam) say 32 front 38 rear but this is for max loading. 32/32 is the correct pressure for normal vehicle loading.

 

[kid-jensen]

Some of the Figures in the report have no target Value, only a tolerance (Rear Camber in particular), which is meaningless.

Also Rear Caster has no figures at all. If this were incorrect, you would get the symptoms you describe.

Might be worth a call to the Aligners to find out why this was not checked, bearing in mind you have an undiagnosed problem.

Is the rear of the car riding harshly, compared to the front? Especially if there is a difference side-to-side. You may have a Shock absorder siezing or running-dry...