Vettechris996

I have an 02 Z06 that I use on the street and for quite a few autoX events every year. Current setup is Pfadt polys, Pfadt inverted adjustable shocks, stock Z06 springs, Pfadt camber kit, -2.5 degrees of camber with 0 toe, and stock Z06 wheels with NT05's on the street (275/295). 2 weeks ago I bought a set of Pfadt heavy rate race bars from another forum member. I knew they maybe a little stiff but it was a good deal and I knew I wouldn't regret having too much bar so I went for it. Well I put them on last week and and have driven the car about 300 miles since then and if feels AMAZING. Today I was pulling into the garage to work on fixing the common ABS module issue when I heard a really bad noise under the car. I stopped immediately and got out to see what it was and I saw the left side arm to the sway bar on the ground. When I picked it up part of the control arm was still attached to the end link! The tab on the control arm sheared off and the arm bound up with the control arm as the suspension articulated and it pulled the arm right off. Mangled the end link and of course the control arm is toast. I got the car jacked up and the bar off and got in touch with Pfadt and sent them a bunch of pictures. Huge shout out to Zack and Aaron for looking everything over to help me out. Everything appears to be installed correctly and we're leaning towards a fluke in the control arm casting but I'm still waiting to get Pfadt's official thoughts. Has anyone ever seen this before? I know its a stiff bar (both were on the medium setting) but I've never heard of an arm breaking like this. Really wanted to know if any has seen or heard of this happening

geerookie

If there is that much of an indentation in the aluminum from the washer, I would say something was seriously over tightened either that or it was so loose it was rotating
Regardless I think that was the cause of the stress which finally caused it to let go. That and maybe a slight bit of binding of the sway bar arm and the adjustable link.

Werks

Before I comment a quick question. If I understand what you wrote correctly the orange sway bar lever arm was completely off of the bar with the end link still attached and a portion of the mount on the lower control arm broken off (but still connected to the linkage/sway bar lever arm). Is this correct?

Vettechris996

Since I've owned the car those nuts have always been torqued with a torque wrench. Either to the factory 53 lb/ft or Pfadt's 56 lb/ft. i don't recall that indentation being there when I put the bar on...


Werks, you are correct. There is a spot just inboard of the boss that that tab should be on where the arm clearly contacted the lower control arm with some force.

When I installed the bar I went through and checked the torque on the clamp bolts that hold the arm to the bar, everything was set to pfadt's specs.

Solofast

Post a pic of the sway bar arm that was laying on the ground...

The failure was, as I'm pretty sure Werks is thinking, that the failure scenario was as follows:

The sway bar arm fell off of the bar. The arm fell to the ground and got wedged between the ground and the lower control arm which caused the damage to the control arm along on the leading edge. Since the leverage ratio was big the sway bar mount got ripped right off the control arm. The fracture surface and failure line is indicative of a simple overstress failure due to a large force pulling upward and to the left (force direction near 10:00 to 11:00). As I said, there is no evidence of fatigue in the failure surface, it is a simple pull type failure, with no signs of beach marks or fatigue striations. The damage to the LCA just inboard and below the sway bar mount is where the sway bar arm hit the LCA

In short, the arm fell off the bar first, wedged between the ground and the arm and ripped off the mount on the LCA. The damage to the LCA was secondary damage.

Some of these older Pfadt bars have an "angled" hole that has a spline in it and that is a poor attachment method. In the past some of these have come loose an failed when the arm cracked across the joint.

Vettechris996

The arm coming off first sounds very plausible. Heres a picture of the arm:



The design appears concurrent with what's on Pfadt's website right now. If there is an issue with it how do I keep this from happening again? As I said I torqued the clamp bolts to spec...

1ED1

I had this happen the bolt came out of the arm the arm came off and
dug into the ground and bent the link.
Called Pfadt at 3pm ect Friday and the part was at VIR the next morning at 9 am. Missed the first session by 5 mins

Thanks Pfadt
Ed

Werks

Solofast is correct, that is exactly what I was thinking and the reason why is because that is exactly what happened to me with my heavy rate sway bars that were bought last summer also. I've refrained from talking about my experience in the hope that it would be addressed by the manufacturer but as you can see from 1ED1's post, it is a known issue. So to be candid if you are being told that it is some type of fluke by people working there I would not be thanking them because they are not being honest/open with you.

In my case a few months ago I had the car (C6Z) up on the lift doing my regular inspection prior to a track day and looking at the front bar I noticed that on one side the orange lever arm had slid all the way off the sway bar and was wedged/captured between the end of the bar and my brake cooling duct. I thought that this was a little strange as the pinch bolt in the arm was still installed and completely tight. As part of the pinch bolt also sits in the groove that is machined in the bar when installed there is theoretically no way that the arm should be able to slide over when the bolt is installed, but it had. So I loosened the bolt, re-installed everything and got a breaker bar and really torqued down on the pinch bolt so that I knew the thing was not coming loose.

A few days later at the track after each heat I inspected the front bar checking for movement of the lever arm and everything looked fine. Last session of the day I'm out on a mid speed negative camber corner and I hear a loud bang and something thumping like it was bouncing along down the bottom of the car for a few seconds. Pull into the pits to look things over and in my case I found that the lever arm from the front bar had fallen off again, gotten wedged under the front lower control arm and the ground and been completely ripped off tearing the sway bar linkage in half.

When I called about this I was also told that they had never heard about this happening and that it must be some type of fluke. Personally I was just happy that I had not crashed by car and/or killed my self or someone else on the track when it happened because being frank this is a major safety issue! I'm not going to get into too much detail about the rest of issues that I experienced trying to get someone there to stand behind their product or the different excuses that I was told but lets suffice to say that through my dealer I ordered a carbon drive shaft, engine mount and tranny mount at the same time (so an easy $2k+ worth of parts from the same people that made the bars) and was charged something like $600 for replacement lever arms and replacement linkages. It was never offered to be replaced as a warranty item or anything like that. For me the last straw was once the parts came in and I then came to find out that I would need to also replace the bar because the splines also got damaged the last time the arm fell off. When paying the additional couple hundred dollars for the replacement bar the person that I was dealing with at Pfadt was kind enough to offer to pick up the shipping on the bar "to help me out" at which point I told him to keep the $20 in shipping and he could stick their sway bars up his ****. I called my dealer and told him that I was done with those bars and that I was sending the bars and sway bar mounts back and wanted my money back. They took care of me and had Aaron personally call me to discuss things. All of my interactions with Pfadt prior to this was not with Aaron, I should be clear about that and if it had been maybe things would have worked out differently but they did not. At that point though between the issue with lever arm falling off twice with the front bar and some issues that I had before with the linkages breaking on the rear bars I had completely lost faith in the product and wanted it off my car.

So again if you are being told that this is some type of fluke it's not. I sent my bars back to Pfadt at the dealers instructions, so they got to see them in person. I also know that one of my local shops has seen the issue before several times and actually had a stock C6 with the bars on it in at the same time as my car with exactly the same issue. We are pushing out cars when tracking them so parts will fail, I do not have a problem with that. But if you are making, marketing and I might add charging for something as a premium racing product, then you should stand behind your product and your customer when there are issues with it. If I had been treated like 1ED1 things might have ended differently but I was not and that is why even though I have just about every product Pfadt makes I'm no longer running their sway bars and pillow blocks. I hope that the eventual outcome of your situation ends up being more positive that mine was.

Solofast

It isn't plausible, it's what happened. No doubt about it. The failure of the LCA is clearly overstress, no fatigue involved based on the fracture surface. The sway bar lever arm fell off the bar first and that is what caused the overstress. If the LCA mount failed, there are no forces that would pull the sway bar arm off of the bar, and it would still be on the bar.

At one time they had a different picture on their web site, but if this is what they have then so be it.

I've mentioned this before, that this is a particularly poor design. The reason is that when you want to clamp something around a circular part, you need to make sure you have material directly across from where you are pinching the circle. Think of it like wrapping a tie wrap around a bar at an angle, and then when it is straightened out, it is loose. Same thing here. With this design when you clamp around the bar you really aren't clamping all the way around, you are just pinching the oval hole around the bar at the top and bottom. If the arm was square around the bar it would clamp a lot better. The second problem is that the arm is made of aluminum. Light weight, but it isn't a very strong material, and if the arm yields just a bit it's going to change the angle (turn a bit straighter on the bar) and it's going come loose.

The high rate bars exacerbate the problem because the forces in those bars are a lot higher than the softer bars.

There have been cases I have seen where the arm has cracked, or gotten loose, and won't tighten back up, and obviously others where the arm has fallen off. None of these is a good thing. If this were to happen at speed in a fast sweeper, you will end up with massive oversteer, which could be really unpleasant, or seriously dangerous, depending on how fast you are going and how many G's you are pulling when it happens.

froggy47

I have not used those multi piece bars from Pfadt, but I have used a lot of their other products & always good service.

Having said that, I never liked the design of those bars, , it just never made sense to me.

I have never seen that CA bar mounting tab fail by itself on any of my Vettes or anyone elses.

IMO this is a case of where the real world stresses trump the engineering/design/manufacturing process that this particular style bar went thru.

If you search it enough you will find more examples of this bar going loose, ever since it was introduced.

Throw it in the trash & put some one piece bars on.

I have used C5 T1 bars for 5 years, hard, and never had one loosen, just a little wear on the bushings (and for myself I like the hard rubber ones with the mesh bonded into the rubber)

If you want to keep the bar, maybe set it mid point & weld it. Make adjustments with a rear bar. More... it looks as the adjustment is at the small end of the arm anyway, so if you weld it up at the big end to the tube you are not loosing any adjustment.

2 cents.

Lucky it did not fail at high speed, if there were such a thing as a sway bar recall, I would vote for that.

Werks

As others are mentioning it's a major safety issue and really should be addressed by the manufacturer. In my case as I mentioned it broke on me while on the track with a passenger in the car. Luckily it happened on a medium speed corner but if it had happened 15-20 seconds earlier I would have been coming off the front straight braking from nearly 150mph going into a 100+ mph sweeper and results could have been completely different. The design is flawed and imho if you are putting around on the street is fine but for track use is a serious concern. I've since switched to LG bars.

Vettechris996

Thanks guys. I'm going to be working on this the next few days and I'll let you know how it goes. I'm not ready to give up on the bars just yet (especially with the $$$ invested) but I wont feel comfortable unless I know this won't happen again, possibly at a worse time so I'll see what happens!

UstaB-GS549

It looks more like a fatigue fracture rather than a ductile failure from the pictures.

I have the T1 anti-sway bars on my car and have always thought that the cantilevered bolt with rod end hooked to a monster bar does not look not well engineered.

waddisme

What happened to my Pfadts. Walked off the end while I was driving down the highway. I had bought mine used so I got nothing from Pfadt but a discount on a new set - no thanks. Threw mine away and repl with T1s.

If they are salvageable, you may want to tap the threads a little longer in the bars so they can be tightened more. IIRC, the bolt bottoms out before it properly torques on the bar itself. Good luck with it.

Pfadt Racing

Thanks for the call and the pictures Chris. I am glad we got you sorted out. We will get you set up with some replacement parts ASAP.

After speaking with Chris on the phone we determined the failure on his car was likely the result of the one arm not being fully seated with the pinch bolt in the allocated groove. When this bolt is not seated in the groove, the friction on the splines will not hold up to that environment for long; a problem that is magnified by the high-camber auto-x setup he is running. After the arm was pulled off because there was no pinch bolt in the appropriate groove, it nicked a step in the driveway and wound up breaking the control arm tab due to the leverage it saw in that event. Unfortunately because they were not purchased from us, Chris did not receive them with the arms pre-installed from Pfadt. This is NOT a failure of our sway bars and more importantly Chris is a great guy and worked through the event with us to get to the root cause. So kudos to Chris for helping us figure it out .

The Pfadt Heavy and Light Rate Racing sway bars are installed on literally thousands upon thousands of Corvette C5s and C6s. With that said, there are always going to be circumstances where these RACE parts are occasionally installed incorrectly, or subjected to events they were not designed for. Over the past 5 years that we have been selling these bars, we have made improvements that have resulted in the optimized product that we sell today. The design is sound, proven and performs at a high level beyond anything else on the market. These have been installed on multiple National Championship winning Corvettes that see severe race duty, including our own. But there are many examples of hard-driven street Corvettes that have 5 years of usage with no issues as well. Overall this is the ideal sway bar package to run on your dual use Race/Street Corvette.

The bottom line through all of this is that we take care of our customers. Even as the gentleman above notes that we will give a partial warranty on parts that were not even purchased from us. I do not believe there is another manufacturer in any industry that will warranty second hand used parts with a discount. There are customers that have had uncommon experiences with our customer service, especially when working through a third-party dealer where information is not accurately being relayed. When customers deal directly with us, you can guarantee that we will work hard to have the same great customer service experience that most people on the forum here back us up on. It is important to us to have people walk away happy with our products and service. And that is what Chris has just found out. "

C5_phillouieambers

And that's how you stand behind a product! My hats off to you guys for taking care of this the way you did

Vettechris996

Guys just to add my updates here. What everyone said above is correct. The arm did come off the bar first, catch on the lip of the garage floor and cause the tab to be ripped off the control arm. What I do know is that the arms were not centered when I got the bar and I reset them on the bar and tightened the clamp bolts to spec. Whether the splines were already damaged in that area or the bolt loosened we'll never know, but something happened. Pfadt was great through the whole process, they worked with me to figure everything out, got me a discount on the parts and made sure I had them the next day. Right now the car is completely back together and on the ground. They also helped me with a few setup tips since I have a camber kit on the car and a fairly aggressive alignment so that any load that wants to pull the arms off the bar is mitigated.

Right now I have a new arm and endlink on the side that was damaged. This time I made sure the splines were good next to the bolt so that it can't slide off easily and I also used a bit of blue locktite on the pinch bolt. Also, for my own piece of mind I ground a small flat on the end of the bar on each end out past the arm and drilled and tapped a 10-32 hole and using loctite again, installed a socket head cap screw. This was should anything at all cause that arm to come loose, it can't make it all the way off the bar. Its probably unnecessary but insurance is cheap!



All in all I am happy with the service I got from Pfadt. Someone always was there to take my calls and answer my questions and they did all they could to make things right, despite these being USED BARS! I think its also important to note that my car is NOT stock, its a combination of many Pfadt parts and various other parts all set to my own settings. Things happen and this is part of the hobby, not everything works perfect the first time around. Pfadt was great to work with and I feel like they did all they could to help, thanks guys!