NHC MOTORS · SERVICE RECORD

Mercedes-Benz E450 Coupe: cracked and bent wheels after a tire blowout

A tire blew out of town and was replaced locally. We found a crack in the front right wheel and bends in the others, then repaired each problem separately.

The E450 Coupe on the alignment equipment

2020 Mercedes-Benz E450 Coupe

A tire blew on this 2020 Mercedes-Benz E450 Coupe while it was being driven out of town. The tire was replaced locally; the car then came to us for a closer look at the wheels.

The front right wheel was cracked and the other wheels were bent. We welded the crack, repaired the bends, replaced two tires and adjusted the alignment.

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Removing the tire exposed marks inside the wheel

After a tire blowout, the wheel needs checking too. Once the tire was off, we could see marks on the inner rim and edge that had not been visible from outside.

We see this model with wheel and tire damage often enough to take care here. The 275/30R20 tires replaced in this job have short sidewalls, with less room to absorb a road impact.

Condition of the inner rim with the tire removed

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Welding the front-right crack and straightening the bent wheels

We secured the wheels on the machine and measured rim runout with a dial gauge as each wheel turned. We welded the crack in the front-right wheel and straightened the other bent wheels.

A crack is a split in the metal. Please watch whether the welded front-right wheel loses pressure faster than the others.

Measuring the wheel's shape with a dial gauge against the rim

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Measuring wheel runout and Road Force separately

After fitting the tires, we put the wheels on a Road Force machine. Runout (mm) shows how much the rim moves as it turns. RFV (kg) measures changes in force as the loaded tire rolls.

One screen showed 0.03 mm rim runout alongside 11.0 kg RFV. A rim can turn with little visible movement while the assembled wheel and tire still react differently under load.

A four-wheel summary screen showed RFV of 2.0 kg for No. 1, 7.5 kg for No. 2 and 5.0 kg for No. 3 and No. 4. It also displayed a TranSaver warning for the difference in wheel diameter. That warning flags a diameter difference beyond the machine’s threshold; it is not a transmission-failure diagnosis.

The damaged tire was replaced locally first. After the car arrived, we separately fitted two Continental DWS06+ 275/30R20 tires.

Measurement screen showing 0.03 mm rim runout and 11.0 kg road force

Separate measurement screen: 6.5 kg Road Force and 0.07 mm rim runout

Summary screen showing RFV and assembly diameter for all four wheels alongside a TranSaver warning

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Adjusting wheel direction on the alignment machine

An impact that bends a wheel can also affect the direction the wheels point on the car. We measured and adjusted the alignment on HUNTER equipment.

If vibration remains at a particular speed or on a particular road surface after the wheel, tire and alignment work, tell us when it happens. That condition needs to be checked on the road.

Alignment measurement screen showing front toe of 3.0 mm and 3.8 mm

Alignment measurement screen showing rear toe of 1.1 mm and -2.1 mm

E450 COUPÉ · WHEEL CHECK

A wheel problem can remain after tyre replacement

After the damaged tyre was replaced, we inspected the wheel itself for a crack and a bend. Wheel repair, rotating-wheel measurement and vehicle alignment address different conditions.

01
Inspect wheel condition
Inspect one crack and a bend in another wheel separately
02
Repair the wheel
Repair the crack and bend as appropriate
03
Measure rotating-wheel condition
Balance and road force are separate measurements
04
Check vehicle alignment
Measure the direction of the mounted wheels with alignment equipment

This process diagram is illustrative. It does not show before-and-after measurements or the final condition of each wheel.

Frequently asked questions

I replaced the tire. Do the wheels still need checking?

Yes. On this E450, the front-right wheel was cracked and other wheels were bent even after the tire had been replaced.

Does a TranSaver warning mean the transmission has failed?

No. It flags a diameter difference among the four wheels beyond the machine’s threshold. Tire size, wear and machine settings need checking together.

Do repaired wheels still need an alignment?

Wheel repair addresses the wheel’s shape; alignment addresses the direction the mounted wheels point. We did both on this car.

After a blowout, check the wheels too

If vibration or pressure loss continues after a tire replacement, have the wheel checked too. Tell us how the damage happened and what you notice now so we can explain the inspection and any repairs needed.

We explain the work and estimate before proceeding with your consent.

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031-258-1617 · NHC Motors, Suwon · By appointment

Published 2026-09-24