My Turn on the 296 wheel of fortune :( - Now with good news!

BMW does a U-turn on suspect alloys and promises a full investigation.

Hit a kerb hard, or clobber a pothole, and you might expect to crack one of your car's alloy wheels, but what if the damage occurs without any obvious cause?

That's a situation which has faced many BMW 3 Series owners recently. Gareth Conyers contacted What Car? after needing three replacement alloys for his 3 Series since October 2008. Another 3 Series owner, Richard Carter, wrote to us after his Convertible suffered two cracked alloys.

Both drivers were told the wheels weren't covered under warranty.

Pattern emerging
Gareth and Richard had more in common than just the make and model of their cars, however. Both had 19-inch alloys with run-flat tyres. What's more, they weren't the only ones with this problem. Online motoring forums have recently been buzzing about cracks in BMW's 19-inch wheels.

The BBC's Watchdog programme highlighted the issue in October 2009. BMW's initial response was to stand its ground, saying: 'Every one of these [cracked alloys] has been investigated by our specialist technicians and in every case the wheels concerned have shown signs of impact damage, which have resulted in the cracking.'

BMW gives in to pressure
Under mounting pressure, BMW has now changed its position. 'We have decided to stop offering customers the affected 19-inch wheels on new vehicles while we look into this matter,' it says. 'Our actions should not be interpreted as acceptance of liability, but rather as a clear sign that we take our customers' concerns very seriously.'

In some cases, earlier decisions to reject warranty claims have been reversed. BMW is now replacing cracked 19-inch alloys with run-flats unless there are clear visual indications of impact damage.

Gareth has had the third cracked alloy replaced free of charge and has been sent a cheque by his local dealer for the cost of replacing two wheels last year. However, he is not happy that BMW hasn't paid for the tyres damaged in 2008 (the cracked alloys caused them to deflate), although the dealer has paid for the most recent new tyre.

We'll let you know the outcome of BMW's investigation.

Have you been affected?
Has your BMW 3 Series succumbed to the cracks detailed in this story? Tell us here
 
Have just watched the watchdog report, very interesting indeed, I'm sure if you all club together and commission a report you could get something back from BMW
 
I'm a bit puzzled and wonder if anyone can anyone shed any light on following apparent inconsistency?
In the Watchdog link posted by Shambolic, BMW's statement to Watchdog says
"If a wheel rim is presented with cracks, a full technical evaluation is made in every case. If the wheel is found to be deflected from a perfect circle by 0.3 mm or more this is evidence that an impact has taken place and this has been the cause of the cracks. In this case the customer would be responsible for the repair. If the wheel is deflected by less than 0.3 mm and yet is cracked, then it will be replaced under warranty."
Yesterday Maniac posted "*Update: 9:26 They are checking all wheels, the first has been checked (with the notable crack) they tell me its out of their 'test' tolerance (measuring .28 when the max is .12 so I'm told). I await the full results."
So if the dealer has measured Maniac's wheel at .28 (which I take to be a measure of deflection from true) isn't this within the 0.3mm which BMW clearly felt was a reasonable tolerance in 2009? Have BMW changed their stance and lowered the tolerance deflection to 0.12mm or are the figures quoted to Maniac by his dealer completely different measures?
 
I would suggest, if the figures above are correct, that BMW was spending a small fortune in replacing wheels and so reduced the tolerance as a profit increasing exercise. As the guy said in the report if you had cracked the wheel through kerbing/pot hole the there would be significant damage to the rim, i.e. a point impact mark.

On a diameter of 482.6 mm a manufacturing concentric tolerance of 0.12mm is pretty good (0.025% of diameter). As a designer of pressure relief valves, I would normally use a concentric tolerance for critical components for a clearance fit of G9 or H9 of 0.05 of up to 20mm diameter, 0.075 up to 100 mm and 0.1 to 250 mm maximum. The best concentric tolerance we can do consistently is 0.03mm, just not on a large diameter!

I would say that this 0.12mm tolerance is unrealistic for the size of the wheel and is thus just one big scam by BMW as far as I can see
 
19" = 482.6 mm

0.12 mm as a % of 482.60 = 0.025 %

Completely agree with you sars, this is an unrealistic tolerance and a complete scam by BMW. :evil:
 
Z4 Beemer said:
19" = 482.6 mm

0.12 mm as a % of 482.60 = 0.025 %

Completely agree with you sars, this is an unrealistic tolerance and a complete scam by BMW. :evil:
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I wouldn't go too mad here, its just what I was initially told over the phone by the service personnel. I could have misheard or they could just have been repeating what they thought they heard from the tech doing the job.
They still have the car at the moment and I'm in another loaner (318i, ooh the power) but should know more before the end of the day.
 
...and the beast is back.

The car has been returned to me, with two shiny, if very slightly differently shaded (presumably due to the fronts being a year and a half old/weathered) new 296 rear wheels. I'm sure some winter abuse will soon sort that out.

After little persuasion, they informed me that the original reading was in error and both wheels were under the tolerance limits. They also said in light of other prior issues, they had pressed BMW away from a contribution approach and gave me the new wheels free of charge. What a weight off. Sadly, no contribution to the tyre wear, but I'll keep on pressing that angle with the original dealer. I feel fortunate enough to not have to pay anything for the new wheels, so don't want to hex my luck in the short term.

They also mentioned, and I'll ask again/report back to you all about this when I visit them next, that BMW had revised their 296 wheel design with more reinforcement around the inner rim. Yet more fuel to the fire for those with not yet, or soon to be, cracked 296's.
 
Are your replacements the updated ones? If so, are there any visual difference to the inside of the rim?

It is a shame about these wheels cracking, because although I like the 18"'s on mine, I do think they suit the Z4. More so than the M sport wheels.
 
There's no visual difference on the exterior of the wheel itself that I can see, its got a slightly blue tint to it which seems to be a thin plastic coat, unlike the fronts. I'm assuming this is part of the redesign or because its new and hasn't weathered yet. You can only tell if you compare them for several seconds+ and looks worse at the moment as the fronts are dirty. I was told it was the interior of the wheel (the part the tyre now covers) that had been revised and the wheels I have are this new design. They told me this as I was concerned about recurrence of the issue. I'll take a closer look later and update this post if its any different.
 
This is excellent news Maniac! :thumbsup: Please do report back about the reinforced design of the inner rim. If I have any issues I'll be quoting this thread and your outcome to my dealer!!
 
Good result :thumbsup:
I mentioned to the dealer before taking car about the 19s and was assured there was no problems(the salesman has now left)
Interesting they have changed the design (although like us in boiler making when we change things), it will be a case of continous improvement rather than previous fault :roll:
 
shambolic said:
...it will be a case of continous improvement rather than previous fault :roll:
Click to expand...

lol yes, of course, natural development, not 'fix'.. just like speed cameras are all about the safety and not the money :D
 
A bit like "quality enhancement" on rear vents in boot last month.
It's a Recall FFS. If I don't get it done my electrics in boot will get wet.
That's not an enhancement in my book. :poke:
 
I do realize this thread is fairly old and the last post was issued last July. I've not been here for quite a spell since I've moved on and traded my Z4 in for a M3. Like some of the members here I also had 2 rear wheel cracks and cracking of rear wheels continues on the other side of the pond. as may be seen here (some posts regarding cracked 296 wheels in the USA & Canada)...
.... If you care to review then click here ---> http://e89.zpost.com/forums/showthread.php?p=11285529#post11285529

Maniac,

I smiled when I saw your subject line for this thread "fortune in deed" ... I am happy to see that your wheel issue has been resolved and it turned out well. Do keep us informed how your wheels are holding out. I noted that there was some sort of redesign mentioned, it is the first I've heard about this.

If you can Maniac perhaps you can let is know how the wheels are holding up for you.

sars,

You make some very interesting and well thought out comments about this issue. I do fully agree with your analysis, only I like to add one item to the equation and that would be the 2.5 degree negative camber that exists on the rear wheels of the Z4. I see the failure mode (and I do call it a failure mode) slightly different, still the stiff sidewall of the RFT is a great contributor. Here is how I see it;-

Air pressure if low along with the stiff RFT sidewall and the 2.5 negative camber will channel a great deal of stresses and inertia into the outermost diameter outer rim tire lip support area. Going over road imperfections (bridge and overpass joints, other road like steps and or small pot holes) will add stresses into the aforementioned area. Stresses as we all know will have to go somewhere and will finally show up as a crack (first a very fine hairline type of crack then the crack will open resulting in air pressure loss). One can compare it to the breakage of a paper clip, when taking a paperclip unfolding it and bending it the result will be building in stresses (in this case bending stresses) and the end result of course will be breakage of the paperclip.

Further facts are, the cracks always show up in the rear wheels (never in the front). The cracks always look the same (propagate from the outer diameter inward toward the wheel centre of the wheel). The main strength of the wheel is on the outside where the spokes act as true stiffeners. The manufacturer and / or dealer likes us to believe the cause to be us going thru potholes, however, there is no physical evidence of having gone thru a pothole (in the majority of reported cracked wheels). Finally our front wheels seam to be okay, so if as the manufacturer likes us to believe we go thru pot holes that result in cracks ... why not the front wheels. :) I am sure more facts can be added to this list by others, for now I think these are some of the major ones.

I've done many mechanical failure analysis in my professional life (now retired) I am somewhat disappointed that BMW does not rectify this issue and offer people a different wheel set when they experience this sort of failure.

Happy Trails Everyone ... was nice to visit again :)

Cheers, Rolf-Dieter
 
My new to me Z4 cracked the rear 296 after 10 days in my possesion. 10,000M
Took to the dealer, BMW replaced the 296 and the RFT no questions.

Big load off my mind for now.

BTW, i have seen a few posts regarding welding the cracks and going about your business.
interesting. Wonder how well they hold up.
 
Good result. The issues with the wheels forced me into getting 326's. Believe me, the thought of not worrying about pot holes etc is very appealing!!
 
I'm still on the replaced 296 rears and have recently fitted new Pirelli P Zeros to the back via a local independent. When replacing my wheels, BMW refused to replace the tyres which had bald areas on the inner. This was my biggest disappointment albeit satiated by the two wheels being replaced FOC. When the Pirellis were put on, I asked the garage to check the rims. All were fine in terms of cracking, however both had minor flat spots, from potholes I knew I'd hit since the new wheels. This has resulted in a slight vibration at 30mph but I'll have to live with that as the damage is too minor to fix, and I'm certainly not buying new wheels only to hit more potholes. I expect the next car I have to have smaller wheels and larger tyres to ensure both no cracking or reduced issues with flat spots. The ride is acceptable, but I do search for potholes while driving continuously, and this is a worry in terms of safety when I really should be looking around my environment. I'll miss this car when I move on, but this with other issues means I will definitely move on when the right car comes along, sad really.
 
Maniac said:
I'm still on the replaced 296 rears and have recently fitted new Pirelli P Zeros to the back via a local independent. When replacing my wheels, BMW refused to replace the tyres which had bald areas on the inner. This was my biggest disappointment albeit satiated by the two wheels being replaced FOC. When the Pirellis were put on, I asked the garage to check the rims. All were fine in terms of cracking, however both had minor flat spots, from potholes I knew I'd hit since the new wheels. This has resulted in a slight vibration at 30mph but I'll have to live with that as the damage is too minor to fix, and I'm certainly not buying new wheels only to hit more potholes. I expect the next car I have to have smaller wheels and larger tyres to ensure both no cracking or reduced issues with flat spots. The ride is acceptable, but I do search for potholes while driving continuously, and this is a worry in terms of safety when I really should be looking around my environment. I'll miss this car when I move on, but this with other issues means I will definitely move on when the right car comes along, sad really.
Click to expand...

Thanks for the update Maniac, glad to see the wheels are holding up for you. One tip I was given by a well experienced Tire Shop Manager in the states, he told me that air pressure has a lot to do with both the cracks and inside toe wear on the Z4 tires. He mentioned with the roof weight in the trunk and some luggage one needs to add 10% more air pressure in the back tires (about 4 PSI). Perhaps this might help you also. No harm in giving it a try. I checked my air pressure every week.

As for moving on ... I am sure you find the right car when you do, in retrospect I'm thinking changing the wheels to forged wheels and Non RFT would have done the trick too. Only in my case I went back to a M3 again since I had one before I got into the Z4. Perhaps some day I'll get back into a Z4 only then I will be very observant about the wheels and tires. BTW the M3 has standard tires all others (except for the M3, M5 & M6) have RFT go figure.

Finally your point of smaller rims is well taken, it seams the cracks are mainly on 19 inch wheels.

Good Luck ... Cheers Rolf-Dieter
 
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