I need some Help from Forum Members

[HerrK]

Rolf,

When you have gone as far as you can with the wheel in one piece. Here's what I would do.

1. Drill a hole (1/8 -1/4" Dia) at the end of the crack to keep it from propagating during the removal process.
2. Cut the crack out of the wheel using a band or sabre saw. Cut 1" or so away from the edge of the crack all around so you end up with a basic rectangle portion with a crack in it.
3. Match mark each side of the crack in at least 2 locations.
4. In line with the crack cut from the removed cut edge towards the hole drilled in #1. Which will now give you the two cracked halfs.
5. Using a magnifying glass 10X or more. Examine the crack starting at the rim edge. A jagged tearing of the metal, near the rim edge, may indicate a rapid fracture. If the crack initiation point is smoothed it may indicate a slower fatigue type fracture, unfortunately it my also indicate the two halfs were working against each other after failure and smothed themselfs. You can also examine the entire length of the crack for material voids/porosity.

[zEdP]

Originally Posted by Alext

ZedEP - that sounds quite harsh. Want to test at 100km/h? Haha

No problem if I can borrow your Hummer H1.

[Mr. ///M3 RD]

HerrK

I will certainly keep this in mind and I thank you. However, if I follow up on this later it will primarily to get to the bottom of it all in the interest of others. I would properly have the wheel and crack totally analyzed, samples taken and the proper test procedures followed and documented (I am certain that your described procedure will be part of it - we have access to a lot of resources that I have been dealing with in the past 25 years of my own specialized mechanical engineering business).

Based upon those results I will at that time either take further steps or drop the matter all together. If indeed the findings are that the crack was a result of hitting something I only will have a few choices;-

A) Keep the car and purchase forged wheels with a good wheel / tire insurance.

B) Trade the car in and leave the BMW behind after 20 years driving them, find something more reliable that will indeed give JOY

C) Last but not least fabricate a nice round glass table using the wheel as main support and a good conversation piece.

What ever happens ... I will write to the Roundel Magazine, they are very outspoken about issues like this and I am sure the Editors will publish my findings, should make for interesting reading I think.

Thanks again for your follow up and input, as always it is appreciated

[rmorin49]

My 2 cents:

If you like your car, buy a nice set of 18" wheels, forged or alloy, and a good set of non-RFTs.

If you are tired of the car or have lost faith in BMW, good luck because you likely take a bath if you try to sell or trade it.

I feel bad for you but such is life. Good luck.

[Alext]

Originally Posted by zEdP

No problem if I can borrow your Hummer H1.

Naa man I need the Hummer to get to work on the terrible roads we have over here!

Hehehe

[teagueAMX]

Originally Posted by rmorin49

My 2 cents:

If you like your car, buy a nice set of 18" wheels, forged or alloy, and a good set of non-RFTs.

If you are tired of the car or have lost faith in BMW, good luck because you likely take a bath if you try to sell or trade it.

I feel bad for you but such is life. Good luck.

+1

Originally Posted by Rolf-Dieter

Based upon those results I will at that time either take further steps or drop the matter all together. If indeed the findings are that the crack was a result of hitting something I only will have a few choices;-

A) Keep the car and purchase forged wheels with a good wheel / tire insurance.

B) Trade the car in and leave the BMW behind after 20 years driving them, find something more reliable that will indeed give JOY

C) Last but not least fabricate a nice round glass table using the wheel as main support and a good conversation piece.

Rolf, your cross-country journal indicates that you had a hell of a good time in your Z4. The last chapter is a disappointment, but somehow I think regardless of how it turns out for you and the wheels, you can enjoy your Z for many more years to come.

I totally agree with rmorin - get yourself some 18" forged wheels, some nice Michelin Pilot Sport tires and put it behind you.

[rmorin49]

The E89 Z4 is one of the best looking cars BMW has built in many years. Is it perfect? Not quite but it is a very enjoyable car. Personally, I think the 19" wheels are a bit of a stretch especially with RFT tires combined with the roads in much of the US. There just isn't enough sidewall to resist the forces associated with hitting a pothole or obstruction. Granted 18" wheels are not going to guarantee that you won't have a problem but it helps improve your chances. Also, replacement costs are less when you do have a problem. There are a lot of good looking 18" wheels available including the BMW OEM wheels I have on my car.

[teagueAMX]

+1

You make some very good points. The Z4 is unique on the market and worth hanging on to.

[Mr. ///M3 RD]

Originally Posted by teagueAMX

+1



Rolf, your cross-country journal indicates that you had a hell of a good time in your Z4. The last chapter is a disappointment, but somehow I think regardless of how it turns out for you and the wheels, you can enjoy your Z for many more years to come.

I totally agree with rmorin - get yourself some 18" forged wheels, some nice Michelin Pilot Sport tires and put it behind you.

No worries Fellows I will change the shoes and keep the car, just love it too much what can I say.

Thanks for all your input and support

[flpnout]

Nice to know you are keeping the car. Sucks that you had issues with your shoes. I had the same 296 wheels. Due to bad roads here in California (especially on I-5 heading from San Francisco to L.A.), I encountered nasty pot holes (not by choice) and bad expansion joints both on the previous 296 and current 326M. I have heard LOUD whack/crash on my steering wheel a couple times and my wheels are still fine. After a few of those incidents, my eyes are even more so attentive to road blemishes. At around 4k miles on the 296 I switched over to the 326M wheels. I have not encountered any signs of cracks after all the abuse. I do like to drive my car pretty hard too, especially in the switch backs.

I will most likely switch to regular tires once my RFTs require changing.