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Frame "tearing" on early models documentation

13K views 41 replies 19 participants last post by  CraigFulton  
#1 ·
So after I read about the frame tearing issues on earlier models. I decided to take action on repairing it before it happened.
I located an Audi certified aluminum repair shop. They knew exactly what I was talking about when I called and exactly what to do already.

I figured I'd post some of the work done here so you guys can check it out.
 
#3 ·
And therein lies the debate.

It's important to note that Audi won't stand behind installing these. There's been a lot of speculation that it's likely due to risk of weakening the frame, as it's notoriously difficult to weld aluminum this way. This is also part of the reason why it's difficult to get the parts from Audi as a consumer.

I know we've talked about frame cracking on this site for years, but in my time here I don't think I've heard of more than a handful of actual incidents. So, it's a very rare thing indeed. It's probably worth considering if you look to proactively reinforce the frame - done improperly (and only Audi can say what "improper" is, and they're not saying much), you *may* be introducing problems rather than solving them. The fact that Audi won't stand behind a shop doing this work is a bit concerning, because it also means they're not sharing potentially critical information such as the alloy mix, which would help inform a welder on their approach.

Personally, I couldn't say whether I'd do it or not (I'm thankful I don't need to make the decision), but I DO know I'd probably do a lot of research on it, including a good deal of time talking to the potential welders before pulling the trigger. I'd want to avoid odds of impairing the car outweighing odds of proactively addressing a problem. Again, given that this is a very rare situation, it means I'd need to have a super high level of confidence in the former.

All of that being said, it looks like the welder here did a nice, clean job. I'm not a welder or metallurgist, so I can only comment on the visual aspects of the job! :)
 
#6 ·
oh wow fellow OG L4P'er

I just had coilovers installed and had the shop inspect my frame and it's looking like new at 32k miles.
 
#12 ·
I did study metallurgy and alloying metals, and though I haven't had a chance to read through all of EZ's posts [which all tend to be spot on anyhow], here are some quick things to consider:

  1. Heating up any metal changes the internal structure of the metal. The exact characteristics of a metal's impact/compression/tensile strength and durability are all defined by that internal structure. How much change to the internal structure during the heating process would determine how much of the original characteristics remain.
  2. Alloys are elements added to a base metal to achieve specific requirements and results, and the percentages of the alloys is very exacting as it effects the molecular structure. Heating metals can cause alloy composition to change.
  3. 7000 series aluminum is weldable. But the temperatures required to melt the aluminum to create the fusion will also leave that melted aluminum [and an area around that melted aluminum] weaker, more brittle, and more susceptible to corrosion. Thus welding 7000 series for the majority of manufacturing purposes is unacceptable. Spot welding, on the other hand, can be used extensively with 7000 series aluminum because the heated area is quite finite and limited to the path the electrical current takes through the disparate pieces.

From what I could find on Audi's aluminum space frames, https://www.european-aluminium.eu/media/1543/1_aam_body-structures.pdf
...no 7000-series aluminum was used at all. It appears be comprised of:

  1. EN AW-6060 - https://www.totalmateria.com/subgroup.aspx?LN=EN&id1=214551&db=N
  2. EN AW-6016 - https://www.totalmateria.com/subgroup.aspx?LN=FA&id1=231868&db=N
  3. EN AW-6181 - https://www.totalmateria.com/subgroup.aspx?LN=EN&id1=7136&db=N
  4. EN AW-AiSi7.5 - https://www.totalmateria.com/subgroup.aspx?LN=EN&id1=234222&db=N
  5. Ecodal 608 - http://www.almetitalia.com/index.php/specialita/meccanica/ecodal-608
 
#17 ·
Yikes. I paid $1100 to have mine done. Audi would not allow their certified aluminum welding shop do my car. Audi told them they would lose their certification if they welded the brackets on my car. That was three years ago.
 
#18 ·
I would love to know why Audi imposed that condition on the repairer.
 
#21 · (Edited)
Ok, I have to weigh in here. I was looking at having my 2009 R8's frame reinforced this past spring.I spent months and a great deal of time looking into it.

I talked to every Audi dealer, and every certified Audi repair shop in my part of the state. The dealers were not even willing to discuss the issue. I then talked to, or visited four Audi certified shops who all told me the exact same thing, "we can't touch this. Audi only allows us to make repairs, and they do not acknowledge this issue as existing. If we made the repair, it could cost us our contract with Audi". The manager of one very large Audi certified shop, who makes all kinds of repairs for Audi even went to a trusted resource in Audi management, someone he has been able to reach out for help from for years, on the technical/service side. He told him, again, this problem does not exist, and even if you were foolish enough to attempt it would almost certainly damage the frame. He also said for Audi to even consider such a thing, a chemical analysis of the existing frame would be necessary at a cost of over $6k, just to absolutely determine that cracks even existed. And even then, he would make no promises. And yes, I saw Audi corporate documentation at two different, very prominent shops that they were not to involve themselves, in any way, with this work!

I then went to three outstanding professional welders, all certified in aluminum welding, with a cumulative ninety five YEARS of welding experience. Again, they each told me that attempting to weld the Audi made plates to the frame introduced too much risk of weaking the existing frame, and they recommended that I drop my plans to have that work done.

I then went to a close personal friend who is near the very top level of Audi world management. I asked him to talk to his contacts. These included the project manager who oversaw the R8 development and initial production. He was told, across the board, that Audi has only ever seen a few (3-4 total) instances of this, and each one related to the cars frame having been abused in a serious front end accident, hitting a curb at a high rate of speed, etc.

I live in the Detroit area. There are endless numbers of world class car repair, welding and frame shops here. NO one will touch this, no one will acknowledge it. It's that simple. To the OP, I hope I'm wrong, but I can only imagine that whoever the establishment was that you worked with, and I absolutely refuse to believe it was an Audi dealer, or anyone, in any way associated with them, had never done this before, had no awareness of it, and simply saw this as a chance to milk you for $5,500.00. That's five times the average price that has been noted by people who have had the work done elsewhere, averaging $1000-1100.00. And that included shops all over the country. Before Audi shut them down, three shops here quoted me "no more than a grand' when I asked about pricing for the potential work.
 
#26 · (Edited)
The manager of one very large Audi certified shop, who makes all kinds of repairs for Audi even went to a trusted resource in Audi management, someone he has been able to reach out for help from for years, on the technical/service side. He told him, again, this problem does not exist, and even if you were foolish enough to attempt it would almost certainly damage the frame. He also said for Audi to even consider such a thing, a chemical analysis of the existing frame would be necessary at a cost of over $6k, just to absolutely determine that cracks even existed. And even then, he would make no promises. And yes, I saw Audi corporate documentation at two different, very prominent shops that they were not to involve themselves, in any way, with this work!
A chemical analysis is not needed by Audi to do this work ... they already know what alloys the frame and the brackets are made out of. In any case, a chemical analysis does not cost $6k ... it costs closer to $100-$200. On top of all that, a chemical analysis doesn't tell you anything about whether cracks are present or not. For that you want to do dye-penetrant testing ... which is another test that costs $100 tops. I know you're referencing high up Audi people, but if this is really what that guy told you (and it wasn't just lost in translation), he doesn't have a clue what he's talking about.

Additionally, welders possess the skill of laying down solid beads of metal, which can be very difficult and deserves respect. However, welders are not engineers and they don't understand anything about metallurgy or mechanical design regardless of their cumulative years of experience. So a welder telling someone that the weld will or won't weaken a structure means less than nothing.

Masters in metallurgy, doctorate in welding engineering, btw.
 
#22 ·
EZMass and others are right and I can see Audi's huge pushback on this repair on the R8 frame. Welding on the R8 heat treated aluminum spaceframe after the fact is no small matter. The heat treat in this case nearly doubles the aluminum strength of the frame. Welding and the resultant "heat affected zone" loses its heat treat and resultant strength in that area. So putting a weld in the middle of a structure where there wasn't a weld to begin with is not a great idea. I hope this works for those who have had it done and doesn't result in another crack down the road. Also wouldn't recommend sport mode either since it raises the suspension forces going into the frame a lot.
 
#23 ·
~~~ Welding on the R8 heat treated aluminum spaceframe after the fact is no small matter. The heat treat in this case nearly doubles the aluminum strength of the frame. Welding and the resultant "heat affected zone" loses its heat treat and resultant strength in that area. So putting a weld in the middle of a structure where there wasn't a weld to begin with is not a great idea~~~
Maybe it does maybe not i don't know but, why would Audi make available the brackets if its so iffy to do. I've got to admit i have my doubts about the frame cracks being an 'issue' but the elephant in the room is why do these brackets exist and why did Audi feel the need to strengthen in that area on later models???
 
#33 ·
You can call 3M hq and ask to speak with someone in structural adhesives technical service. They will provide you with exact instructions and the correct product to use. 651-733-1100.
 
#38 ·
The speculations of the pros and cons of welding in the Factory issued aluminum gussets is all over the place. I have had them installed on my 2010 R8 by a local NASCAR race shop. There is a YouTube video out there where an Audi engineer gives a journalist an in depth tour of the factory build of the R8 chassis. No mention of a heat treat process at all. "gallag4" hit it right on the head. There is no documentation anywhere stating the heat treating of an Audi chassis. Further more, we've all heard of the rare case of frame cracking, typically accompanying an explanation of an extreme event, or a second hand owner that realized the issue after purchasing the car used. No doubt, we've seen the videos and pictures. But, and a BIG BUT, has anyone in the world seen evidence of frame failure due to welding on the R8 frame after factory construction. I would venture to say that for every documented frame cracking issue in the shock tower area, there has been 20-30, or more, gussets welded in as a preventative measure. When they were first offered to the public, they flew off of the shelf. I also believe there has been ample time for a problem to rear it's ugly head if there was an issue with welding the aluminum chassis. So, that being said, get your R8 out of the garage and enjoy it. Happy motoring friends.

Dwight
 
#40 ·
From what I can find about the Audi ASF technology, there may be at least 2 reasons that Audi is reluctant to endorse welding outside of the control and conditions of their manufacturing plants:
  • high volume of aluminum extrusions as structural members - post-manufacture heat exposure would weaken the extrusions
  • rapid hardening aluminum alloys that go through heat treatment after forming - post-manufacture heat exposure would weaken these structural components
Heinrich Timm—Head of Lightweight Development, AUDI AG...were doing something that even people in the aluminum industry at the time didn’t think could be done....

When he started, aluminum elongation in production was on the order of 1%. The limit—really stretching things, literally and figuratively—was 3%. “I asked for 15%,” he states in a rather matter-of-fact manner. He knew that in order to create a truly lightweight structure predicated on diecastings and extruded sections—sections that changed in dimension in order to fulfill structural purposes—he would need to get better performance from aluminum....

...there were other challenges that the people at the Audi Aluminum and Lightweight Design Center had to address...manufacturing processes had to be developed in order to make the vehicles cost competitive. By and large, the auto industry is predicated on stamping and welding, and here they were with extrusions, diecastings, and sheet...rather than relying on spot welding for assembly, they developed punch riveting, adhesive bonding, and laser-MIG hybrid welding processes. Self-tapping screws are employed, as well. One consequence of this (beyond the highly rigid structures) is that they have been able to increase the amount of automation in the manufacturing of the vehicles from about 25% when they started to over 80% today.

This capability has [allowed] Audi to produce more than 550,000 vehicles with ASF, including the A8, TT, and R8, as well as some 9,000 Lamborghini Gallardos.

The latest manifestation of Timm’s structural engineering prowess is the 463-lb. spaceframe employed for the 2010 R8 5.2 FSI quattro...
Rapid-hardening alloys developed specifically for use in the ASF construction eliminate a separate heat exposure process during body production. These new alloys achieve comparable strength to conventional alloys, but cure at lower temperatures and in less time, preserving integrity and tensile strength and virtually eliminating flow lines.

The new alloys are used exclusively in interior structural areas where its higher strength and energy-absorption potential is especially beneficial. The new alloys are heat-treated at the paint shop, eliminating steps in the build process, saving time and cost.

Alloy panels, both delivered as blanks and on a roll, are heat-treated after forming. This increases tensile strength while affording weight savings as compared to panels that are not exposed to heat-treating. The process also has an aesthetic benefit: post-form heat exposure renders the alloy panels almost impervious to permanent dents, such as those caused by hailstones and parking lot “dings.”