Checking condition of used Fuchs
 

I am considering purchasing a set of used Fuchs. Whats the best way to do a careful inspection for cracks and potential failure points? Magnaflux? Or...?

Anyone know who to see in the LA area to get used wheels checked out? Any idea of the cost? I have seen some pretty scary photos of wheel failures . I dont wan to be next to experience that if I can help it.

Oh..and sorry.....I didnt do a thread search. Forgive me if this info has been posted 100 times ! :o

Thanks.

Try Al Reed hes been around them long enough

The other day on the Early 911S Registry, someone was asking about X-raying some Mahle gasburners for cracks in the Magnesium. Harvey Weidmann said he can do that service and he claimed a reasonable price. You might call or email him through the Early 911S board. Fuchs being forged Aluminum (alloy) should be more robust than the Magnesium gasburners. The forged Fuchs are very robust but there have been a few failures now that the oldest ones are getting near a half-century old. Still not as many as the new "Fachs".

Thanks for the replies guys.

Come to think of it...Magnaflux wont work on Aluminum. Will it ? How are Aluminum parts crack checked? Ultrasound ? Aluminum aircraft parts get checked , right? I sure hope they do anyway. :eek:

Any Mechanical or Materials Engineers out there care to add to this?

Thanks.

Aluminum melts in an induction furnace so it should be able to Magnaflux. Aluminum takes longer/ more power to melt via induction than does iron or copper because of its weaker magnetic interaction (coupling?) so the Magnaflux may need more power to be effective.

dye penetrate is the choice for Aluminum parts. a kit is about 50 bucks (from aircraft spruce) but it's just for cracks/surface imperfections, x-ray is the best for internal flaws. And you don't have to clean them of all the paint like the dye method. Magnaflux is for ferrius metals.

wow, you guys are so meticulous. I would just visual check and ask to put it on the car to test spin to make sure it's true. And if possible, spray water dry it off to make sure if it shows any hair line crack.

X-ray is the way to go. The start of this video has an example of x-ray pics

YouTube - Felgenkunde 4/5

i have always heard that fuchs bend before they break, IE, no cracks.

i just bought a bmw 325, the wheels had some dings out at the edge, so i put a dial gage on them to check to see they are true. i am not sure what is bad enough to notice, or if the wheel is really out of true, because where one ding is. the rim could be just dented out. anyway, one was .010 of an inch and the other was .070". i could feel were the ring bulged out at the one ding, so i am still not sure if it is bad, i have not been able to drive the car yet to see if it vibrates.

what i did was mount my dial gage on a secure object, jacked the car up, spin the wheel around . maybe this will help you decide.
i would be more concerned about trueness.

"i have always heard that fuchs bend before they break, IE, no cracks."

On occasion, they crack. Some photos in the archives confirm that.

Magnaflux is a trade name for crack-testing ferrous metals. The company also has a process for testing non-ferrous materials. Apparently, they also own the Zyglo trade name (flourescent dye test).

If your application requires the utmost safety, I'd test.

If you're buying used wheels for your street car, it's up to you. A close physical inspection along with one of many crack-testing kits might be prudent.

Sherwood

Not true. Aluminum affects a magnetic field.

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Except for making me sleepy, it sounds like this method is designed for mass production inspection rather than one-off parts. They may need a response pattern to compare and conclude something is amiss.

Sherwood

Look for radial cracks between the lug nut holes and the triangular hole between paddles. I've seen 7Rs crack there, one even had TWO cracks in it, guy KNEW this and the guy was still running the car. I said something like, "if you want to kill yourself why don't you jump under a bus?"

Well, my post was to mostly correct the misinformation. As to production vs one-off parts... first; wheels are not generally "one off." Second, wheels have symmetry. --this means a single Fuchs (5-spoke) could be tested, turned 72°, retested . .. turned 72°, retested . .. turned 72°, retested. With each test compared to each other. --they should all appear the same.

Thanks you guys for all the good info.
Sounds like x-ray is a good way to go for a thorough check.

Like Flieger said...some of the early 5 spoke Fuchs will soon be getting to 50 years old. I will check with Weidmann or Al Reed to see what they charge for an x-ray inspection.

By the way , is the Fuchs company still in business? If so, are they producing any limited runs of the old classic 5 spoke Fuchs wheels? Or are there any plans to?

Even if they are making any ..or would in the future...I probably couldnt afford them !

Yes Fuchs is still in business and Porsche is selling or at least showing the they have some sizes of 15" Fuchs and 16" Fuchs available. Last time I checked at Sunset Porsche in Oregon the 16x9's were around $830 each. And 8's were more expensive than that.

Normally Fuchs will bend before breaking but there have been more of them showing up with cracks and one on a thread here which broke (didn't bend). Porsche uses cast wheels on the cars now which are x-rayed to verify integrity. So cast wheels are not as bad as everyone seems to think they are as they have been designed with the manufacture process in mind and making them strong enough to deal with the forces that effect them. Even cars like the Ford GT came with cast wheels as standard equipment and offered the forged wheels as an option.

Wayne here at PP sells the Euromeisters and the Fox wheels both of which are cast. They are both heavier than the forged Fuchs to give added strength due to casting the wheels. No reports of ether failing on the street or track.

Remember most of the cars on the road have cast wheels not forged and we don't seem to worry that they will come apart and cause great bodily harm. My Porsche does not see pot holes like my daily drive sees and around here there are some giant wheel bending ones. When was the last time we have seen cast wheels that come on most cars come apart unless they were damaged.:cool:

Thanks 88-diamondblue;

Good to know Fuchs is still around. I seem to recall reading that they made the rollers for German Panzer track assemblies during WWII. And I assume other Wehrmacht vehicles.

I was looking to buy 2 16x7's and 2 16x8's for track use..therefore I am a bit concerned about cracks and the integrity of the wheels. I agree..for street use, probably not a big problem. I cant remember the last time I saw a Porsche at the side of the road with a broken Fuchs wheel !

If new 5 spoke Fuchs 16x9's are going for around $830 each, (!!) and 8's more expensive than that :eek: , I will get a good set of used ones that have been carefully checked by Weidmann or Al Reed.

Thanks!

Priced at... inquire

*: Otto Fuchs KG

Wilhelm they are out there just a matter of time before somebody lists some.
Sunset Porsche in Oregon. They may be higher now. Imagine that happeing:rolleyes:

Here is the Porsche site that lists what is available for Fuchs New Editions - Classic Catalogues - Porsche Classic - Dr. Ing. h.c. F. Porsche AG

Thanks Flieger, Diamondblue, and island911 for the price info . I should have done more "Googling".

Ach du Lieber ! My assumptions about the price of new Fuchs has been confirmed. When I am ready to buy, I will find a good set of used wheels - that have been carefully inspected - from Weidmann or Al Reed. A used set plus the inspection/x-ray certainly must be less expensive than the new ones.

Unless someone here is mass-producing factory Fuchs, tell me who has such a setup as shown in the video for testing used wheels I buy from a private party?

Sherwood

You know when I first saw that Magnaflux Quasar machine I could only think of this.:D

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will they break? i have never seen any info on fuchs, just what people say.

wth is with the attitude? I never suggested that people go get their used wheels magnufluxed. I was just saying that it could be done. I was simply giving a response to when you and another gave misleading technical information.

...ah, I corrected you - that's why you have a hair up your ass. (squirm squirm)

Most NDT is something left for a tech to do regardless of what method. A quick check with a 10x glass should be fine. And if you find something questionable, take it to an aircraft mechanic at a nearby airport to have them check it out. That should be the quickest and cheapest route

+1

For a forged wheel, signs of fatigue will show at the surface first.

What? This is a video of resonant inspection no magnetic field needed.

An eddy test works on aluminum and is very common in wheel repair and also to test scuba tanks.

My bad ... shouldn't have used the term "magnaflux" so loosely. (like xerox, Kleenex) the video (a Magnaflux inspection product) isn't using magnetics.

...but, point being, as you say, (magnetic) eddy currents work for Aluminum. (which was my original point)

OK, we all agree that Aluminum is affected by a magnetic field but has less coupling than does ferrous metal. Eddy currents work to some degree or another on both.

This means that magnetic dye can be used to find those eddy currents along cracks provided the field is strong enough to make it visible.

(insert icon of dead horse here)