Cracked Alloy Advice

[Fastcar155]

Hi , In reality are alloy wheels strong enough in the first place.

If you have your alloy wheels repaired from a correctly coded welder you may have a better chance of a strong and successful repair.

The problem is that depending on the alloy type / structure of the wheel you require the correct welding rods / gas to obtain a good weld.

To have an chance of a successful repair the wheel the wheel has to be totally clean of foreign bodies.

Each repair will be different depending on numerous factors.

Mercedes alloy wheels are expensive so I totally understand the temptation to repair alloy wheels.

In conclusion I feel that the use of the wheel and the type of car the wheel is being put on should dictate the position.

If you only drive the car around town at slow speeds could be OK but refitting a repaired wheel on a proper AMG or any high performance car is at the very least questionable.

 

[johnsco]

A correctly-specified and designed alloy wheel is certainly strong enough for use on a car.
They use aluminium wheels on aircraft and they use aluminium for many other structural parts on aircraft.
However - Aircraft wheels are inspected regularly for cracks - and other structural parts are inspected regularly for fatigue cracking.

 

[Gbrowncls55]

Of course alloy wheels are strong enough for cars on a normal road surface. But clearly not if you hit a pothole (of which there are many and deep in some areas) or we would not have all the people on here with cracks.

 

[grumpytosser]

same issue on my 20's i had mine re-welded 4 times and it kept leaking

just found that tyres has a hole in it now too right on the shoulder it took 3 garages to find the puncture!

so im looking to replace them with 19's with non runflat runner but really cant face spending 2k on a set of wheels used wheels and tyres

 

[johnsco]

Some years ago, when I was Technical Manager for a service inspection company, a friend of the owner brought a very-expensive looking alloy wheel for an X-ray of a weld repair.
The X-ray showed the wheel to be cracked around the repair.
We marked the area for rework.
The owner took the wheel and had the defective area ground out and rewelded.
He brought it back for an X-Ray of the new weld-repair.
The X-ray showed it still to be cracked.

Not all alloy wheels are manufactured from the same aluminium alloy or with the same final heat treatment.
It is much more difficult to carry out a successful weld if you do not know the metallurgy of the wheel you are welding.

Safety-critical welds in aluminium and its alloys are usually subjected to X-ray and liquid-penetrant nondestructive-testing examination.
Criteria for acceptance are usually specified by the relevant design authority.
Costs involved are prohibitive for mass-produced car components.
Formula 1 is a very different ball game.
Everything is pared down to achieve absolute minimum-weight and maximum-performance.
Cost is no object !!!

 

[chic0821]

For every 20 welders of steel you will find one good welder of aluminium and its various alloys.
Aluminium welding is much-more specialised than welding of steel.
Weld-repair of a crack uses intense heat.
This heat changes the metallurgical properties of the material adjacent to the repair.
This is known as the heat-affected-zone (HAZ).
Stress-relieving of the area around the weld is unlikely to be done in a local repair shop.
There is a significant risk of a further crack occurring around the edge of the HAZ.
Part of my work as a nondestructive testing engineer was the crack detection of welds in aluminium structures.
I would not have a weld repair to any wheel on a car of mine.
Unless .... It was done by a "coded welder" qualified for welding aluminium.
and ...........It was then subject to testing using X-ray and / or dye penetrant test.
Sorry to be so cautious, but my experience causes me to be extremely-cautious of welds in aluminium.

As a Design Engineer its good to see a proper answer with a full explanation, not just "weld it or not" The important part is the qualified welder followed by the stress relieve & NDT ie X ray/dye pen

 

[Fastcar155]

As a Design Engineer its good to see a proper answer with a full explanation, not just "weld it or not" The important part is the qualified welder followed by the stress relieve & NDT ie X ray/dye pen

Hi , members need to read as to why Mercedes Benz don't approve repairs of alloy wheels.

 

[geoffus]

Hi , members need to read as to why Mercedes Benz don't approve repairs of alloy wheels.

I don't think they approve of any repairs, diamond cutting or refinishing of their alloys, it doesn't mean you cannot get a safe and proper job done.
I had my front wheel repaired after a slight buckle was noticed, the car park of the repairers was full of late model dealers cars awaiting refinishing, some had all 4 wheels off on stands.
I can think most second hand cars have had all their alloys refinished or repaired, I guess that goes for Approved Mercedes cars as well.
Is their any manufacturer that approves of refinishing ?

 

[BIGEL]

Ardwick, geoffus, vijilants, johnsco and Bobby Dazzler
Thank you very much for your response

 

[B4mrs]

Hi All
I took my A35 to have a slow(ish) puncture fixed only to be told the tyre is fine and it is the alloy wheel that is cracked! I've found a reasonably local place (20 miles) that repairs alloy wheels. The chap told me absolutely not to drive it and to take my wheel off and bring it to him. No problem I thought until I opened the boot to discover no jack and just a compressor and goop!!
So now I'm a bit stuck. I'm thinking maybe I'll just buy the same alloy off eBay and then get someone out to swap it over.
Has anyone had a similar experience or got any advice? Also, and this may seem a silly question, are all 4 alloys on the A35 the same or is there a difference between front and rear?
Any help greatly appreciated!!

Hi I’ve got a b200 w246 with Angeline trim wheels I’ve had 2 wheels crack and I’ve just got in touch with Merc Uk who said they would arrange inspection with dealer which they did , it went in and they could see no kerbing or damage all 4 wheels were oval in shape and going to cost £2600 cars only done 40k and Merc don’t want to know , I’ve had in excess of 25 Merc’s over the years from a to s class and never had this issue I’ve emailed Merc stating wheels are not fit for purpose under consumer act or giving fair use I’m waiting for reply

 

[Funkyboy]

Just look for an alloy wheel welder in your area. They are perfectly fine to repair but as others have said needs to be a specialist in alloy welding. It's £35 a crack in places by me but yiu have to bring them the wheel with the tyre removed

 

[jonboyE63]

I've had cracking issues this year - poor road surfaces in rural Dorset are to blame.
Both rear wheels have been welded recently & both welds have held up well - was thinking about changing the wheels but I wouldn't know what brand was better than OEM - has anyone else had any experiences of alloys that stand up better then the OEM Mercedes 19's on my E63..??

 

[Flyinspanner]

I've had cracking issues this year - poor road surfaces in rural Dorset are to blame.
Both rear wheels have been welded recently & both welds have held up well - was thinking about changing the wheels but I wouldn't know what brand was better than OEM - has anyone else had any experiences of alloys that stand up better then the OEM Mercedes 19's on my E63..??

Maybe expensive forged alloys (as opposed to cast).
or Steel Wheels?

 

[jonboyE63]

Maybe expensive forged alloys (as opposed to cast).
or Steel Wheels?

Was thinking about banded steels but would need some serious fitment advise if I was to go down that route..

 

[rf065]

Was thinking about banded steels but would need some serious fitment advise if I was to go down that route..

I used a road often that was full of potholes, driving a works light van with steel wheels. OK, no cracks like you get with alloys, just 3 buckled wheels instead.
A buckled wheel is 100 times worse to drive on than a cracked alloy!

 

[alabbasi]

Factory alloys are usually forged and not cast. However if you want to replace your wheels, find a smaller wheel that will clear your brake discs and fit taller profile tires. Nobody ever complained about cracked wheels when we ran cars with 13" tires on 80 profile rubber.

 

[rayaans]

Of course alloy wheels are strong enough for cars on a normal road surface. But clearly not if you hit a pothole (of which there are many and deep in some areas) or we would not have all the people on here with cracks.

Most of the time its the tyres rather than the wheel itself.

Runflats are the culprits, as are the excessively high tyre pressures that the dealers run - sometimes 40psi. Where is the energy supposed to go if theres no give in the tyre to cushion the blow? Straight through the wheel, and almost always on the side without the spokes as its the weakest part.

 

[jonboyE63]

Most of the time its the tyres rather than the wheel itself.

Runflats are the culprits, as are the excessively high tyre pressures that the dealers run - sometimes 40psi. Where is the energy supposed to go if theres no give in the tyre to cushion the blow? Straight through the wheel, and almost always on the side without the spokes as its the weakest part.

Thanks - that's good advise, no runflats on my wheels but i'll check my tyre pressures as maybe they're to hard & that won't help, the cracks have been inside the rim.