Cracked Alloy Advice

[no1duncan]

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!!

 

[clk320x]

How far is the alloy repair shop?

 

[SpikyMikey]

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?

Not a silly question as many Mercs have staggered fitments, but it appears your A35 has the same front and back:

https://www.alloywheelsdirect.net/m..._hatchback_alloys/f/all/amg/all/all/price_asc

 

[no1duncan]

Not a silly question as many Mercs have staggered fitments, but it appears your A35 has the same front and back:

Thanks Spiky!

 

[no1duncan]

How far is the alloy repair shop?

It's about 20 miles away

 

[st13phil]

I'm thinking maybe I'll just buy the same alloy off eBay and then get someone out to swap it over.

I know this isn't what you'll want to hear, but chances are - as a direct result of the horrendous condition of our roads - that another wheel will suffer damage at some point during your ownership.

If you can afford it and have space available, I'd suggest buying a replacement wheel and swapping the tyre over (BTW, if it's taken a thump hard enough to crack a rim, it's worth having it checked for damage to the carcass), and get the cracked rim welded so you have a spare available.

 

[no1duncan]

I know this isn't what you'll want to hear, but chances are - as a direct result of the horrendous condition of our roads - that another wheel will suffer damage at some point during your ownership.

If you can afford it and have space available, I'd suggest buying a replacement wheel and swapping the tyre over (BTW, if it's taken a thump hard enough to crack a rim, it's worth having it checked for damage to the carcass), and get the cracked rim welded so you have a spare available.

Thanks mate. Sounds like good advice to me, I'll get myself on eBay!!

 

[BIGEL]

I recently suffered a cracked alloy. I had a slow puncture. I had it replaced by my local Mercedes dealer at a cost of £1077.00. It was a 20 inch special AMG wheel. I still have the cracked alloy. By the way I had to request the return of this otherwise the dealer would have kept it. I’ve had differing advice about having it repaired. Some say it’s fine others say it’s not safe. Does anyone have any advice please.

 

[JHS]

I recently suffered a cracked alloy. I had a slow puncture. I had it replaced by my local Mercedes dealer at a cost of £1077.00. It was a 20 inch special AMG wheel. I still have the cracked alloy. By the way I had to request the return of this otherwise the dealer would have kept it. I’ve had differing advice about having it repaired. Some say it’s fine others say it’s not safe. Does anyone have any advice please.

Just had a similar crack welded. Keeping my eye on it but it seems ok so far. Not sure why people say that welding is not safe.

 

[Gbrowncls55]

I got so fed up with cracked alloys on my CLS55 19s (I am in pot hole ridden Surrey!) I bought a complete spare set from ebay (different front and rear). I must have had 4 cracks welded in different wheels by a professional wheel place over the years and not one has failed, some over 6 years old, so my experience of repairs has been good. Things are exacerbated now by those particular wheels no longer being available.

 

[vijilants]

On my W204 I had two wheels welded by a reputable alloy wheel company. One of the wheels had two cracks.

After repairing, one of the wheels, again it cracked along the outer line where it was welded and it had to be rewelded.

I was advised that the issue was due to the fact that the weld point is now the strongest part of the wheel.

AMG and BMW alloys have a reputation for cracking. The only options are weld the crack and hope for the best, replace the alloy and again hope for the best, or purchase a full set of forged (stronger) alloys, which can be a very expensive option.

This time around on my C43 I have taken out alloy wheel insurance with Tidy Alloys. It won't cover the full cost of a new alloy but it will cover a good percentage.

 

[st13phil]

Not sure why people say that welding is not safe.

It depends upon whether it's done properly or not.

If not done properly (with appropriate heat treatment), welding an alloy wheel can result in stresses being "locked in" that may result in catastrophic failure in use.

 

[BIGEL]

JHS, Gbrowncls55, vijilants and st13phil,

Many thanks for your response and advice.

 

[Ardwick]

After repairing, one of the wheels, again it cracked along the outer line where it was welded and it had to be rewelded.

I was advised that the issue was due to the fact that the weld point is now the strongest part of the wheel.

An alloy wheel is just a round block of aluminium, it's not some special material. Almost all alloys / metals CAN be welded, but that doesn't mean you should blindly say Yes or No. Most welds on minors cracks (as OP image) will be fine, subject to the above caveat, as the weld will be the strongest part of the wheel and any further impact stresses are distributed differently once it has been welded. It is not unusual for any new cracks to be alongside a repair.

 

[geoffus]

We had our B200 wheel welded after discovering it had four small cracks, after a year the cracks reappeared so I bought a used wheel and tyre from ebay.
I then resold the cracked wheel back on ebay, a chap picked it up and said he would again repair it and use as a spare as non are carried in that model.
I think it was crappy welding that gave up, I used to work in the aircraft industry and the welding done there was an art and was the strongest part of the job.
My lad has just had his Ford Focus wheel repaired, the weld there is beautiful and properly done.

 

[vijilants]

An alloy wheel is just a round block of aluminium, it's not some special material. Almost all alloys / metals CAN be welded, but that doesn't mean you should blindly say Yes or No. Most welds on minors cracks (as OP image) will be fine, subject to the above caveat, as the weld will be the strongest part of the wheel and any further impact stresses are distributed differently once it has been welded. It is not unusual for any new cracks to be alongside a repair.

An alloy wheel is not just a round block of aluminum. It is a combination of multiple materials, hence why they are called alloy wheels.

I merely gave the the options available regarding welding and possible outcome, speaking from experience.

Hope this helps.

 

[Ardwick]

An alloy wheel is not just a round block of aluminum. It is a combination of multiple materials, hence why they are called alloy wheels.

I merely gave the the options available regarding welding and possible outcome, speaking from experience.

Hope this helps.

Thank you for pointing out why they are called 'alloy wheels" I didn't really see the need to explain the differing alloys used in the construction of alloy wheels or the relative merits of cast or forged construction when agreeing with you that any weld is usually the strongest part of the wheel post repair. I too am speaking from experience, as my business refurbishes around 2,000 wheels a year, including welding cracks where it is safe to do so.

 

[vijilants]

Thank you for pointing out why they are called 'alloy wheels" I didn't really see the need to explain the differing alloys used in the construction of alloy wheels or the relative merits of cast or forged construction when agreeing with you that any weld is usually the strongest part of the wheel post repair. I too am speaking from experience, as my business refurbishes around 2,000 wheels a year, including welding cracks where it is safe to do so.

Apologies if I misinterpreted what you were attempting to say , but by initially quoting me I was under the impression that you disagreed with what I had written.

Hope this helps.

 

[johnsco]

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.

 

[Bobby Dazzler]

Thank you for pointing out why they are called 'alloy wheels" I didn't really see the need to explain the differing alloys used in the construction of alloy wheels or the relative merits of cast or forged construction when agreeing with you that any weld is usually the strongest part of the wheel post repair. I too am speaking from experience, as my business refurbishes around 2,000 wheels a year, including welding cracks where it is safe to do so.

Nice to have an expert on the forum. Prepare for the deluge of wheel questions and queries!