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Discussion Starter · #1 ·
I was driving home from some errands yesterday when I experienced the titled problem.

I turned left out of a parking lot, no curbs, bumps or the like (except for reflecters in the road) with my throttle in the appropriate "enthusiastic" position when suddenly at about 30-35 mph I felt violent shaking from the rear followed by signifcantly increased resistance. It felt like a flat tire, so I pulled into the gas station across the street and found what you see in the pics. A bent brass colored bracket was found sitting on the diffuser tray (rescued it and put in in the car).

The wheel was found rubbing against the wheel well lining, and the car was not drivable (backing up pushed the wheel more firmly into the wheel well).

The car got towed to the dealer last night, and I went by to check on in it this afternoon. It turns out that the two bolts that hold the upper control arm to the wheel lost their heads. Yep the heads popped right off the bolts. WTF? It doesn't appear that any other mechanical damage was caused by this mishap, I'm just glad it didn't happen on an auto x course or on the highway.

Anyone else have this experience or have thoughts? Do you think the bolt could have been over torqued at the factory? If it matters, the car has 15 k on it. Never had slicks, never taken any damage to the wheels or suspension.

Tire Automotive tire Wheel Alloy wheel Rim


Tire Alloy wheel Vehicle Automotive tire Wheel
 

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Discussion Starter · #7 ·
Ian said:
Wow; sorry to hear about this. Didn't you just have some work done on your car? Could this possibly be related?
I had some minor clam work done, nothing mechanical. I can't conceive how the two would be related. I've driven about 1500 miles since picking it up, and this is the first unusual thing that has occurred.
 

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Discussion Starter · #11 ·
Randy Chase said:
Mine did exactly the same thing two weeks ago. Much worse looking though. Pulled out the driveshaft.
Holy crap! I guess I got off easy. Under what circumstances did your break? Did Lotus give you a hard time? Should I ask them to cover my rental?
 

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Discussion Starter · #17 ·
Chris said:
I had the exact same thing happened to me at the track, except my wheel folded over mid corner!

The car spun 90 degrees and I let the car roll backwards off of the track to get out of the other drivers way. Fortunately I did not hit anything and there was no body/frame damage. It was towed to the dealership and they replaced everything in the rear suspension under warrenty. I just pray it never happens again! I was actually glad it happened at the track and not on a highway off-ramp in traffic!

Everyone should pull off their wheels and check the torque on the 2 bolts that hold the upper control arm together. I had the mechanic put paint on the new bolts so I can visually confirm they are not moving.

Sorry to hear it happened to you, I don't think it is all that common.
I guess I really did get off early. This type of thing scares me because it is so unpredictable.

As far as it not being common, I think the three of us all having similar problems under essentially normal driving circumstances makes it too common.

***Just out of curiousity, which side was the problem on? If we all have had problems on the driver's side I'm thinking this go indicate a significant design flaw. That said, I'm not sure it isn't a design flaw if it occurs on both sides....

Thanks for all the input.

Joe
 

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Discussion Starter · #21 ·
MitchT said:
I feel like putting safety wire, tabs and paint on all my bolts but I am parinoid about stuff falling off on the track. Nut and bolt the suspension before tracking.
How small do they make lojack type radio transmitters? j/k
 

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Discussion Starter · #25 ·
codymac said:
Control arm to chassis in this case - we misunderstood.

Guessing, due to your question, that this thread is about the ball joint carrier to the hub carrier?

I think you are talking about the same part that I am. I found this pic on the sands museum website, but i don't have the software to draw arrows. the bolts that broke are beneath the ball joint and attach to the hub carrier behind the rotor. (I think).

Motor vehicle Technical drawing Auto part Drawing Line art
 

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Discussion Starter · #29 ·
Chris said:
In my case it was the bolts pictured here that broke causing the control arm to seperate. (there are actually 2, only one is pictured) These are the bolts you would remove if you were to pull your shims.

I have always suspected that they were not torqued on properly which should be a part of the PDI ritual then checked again at first service since it is an obvious problem. This ultimately led to them loosening then breaking.
So yours were on the front.... :confused:

Maybe Lotus should start checking all of these on the cars that come through their shops? I'm not sure what the actual incidence of this is, but considering that each one could theoretically cost Lotus thousands, (if not much more in the situation of a fatality occurring as a result) and checking each car would be relatively cheap, it might be a good idea that they do this. Just a thought. Are you listening Lotus?
 

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Discussion Starter · #37 ·
MattG said:
I was curious, so went out and took a look at mine. You're able to view them without removing wheels, so I grabbed a couple pictures, one of each side's top rear inboard control arm bolt. What I find interesting is that the rotation-stop-flanges appear ineffective, or perhaps just improperly used. Note the green paint - the bolts have rotated sometime after assembly. None of the bolts are protruding through what appears to be lock nuts on the ends. This is not very encouraging, looks like I need to rebuild all these joints with new bolts and new anti-rotation plates? Or am I just being overly paranoid?
Thanks for the pics, Matt, and NO I don't think you're being paranoid. If this thing comes apart on a highway or other high speed scenario or near other cars, the results could be tragic.

When I talk to the good folks at the service center I will talk to them about this. If they don't do it, I will.
 

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Discussion Starter · #38 ·
ChrisH said:
According to the service manual, the bolts you showed (whether front or rear wheels) are supposed to be secured with a thread locker (Loctite or equivalent). However, when I removed the shims on my front wheels, I noticed that the bolts had NO thread locker. Apparently the factory doesn't always follow its own rules. When I put the bolts back, I did use thread locker. Maybe I'll remove the rear ones now and put them back using Loctite, just to be safe.

Of course, that doesn't matter if the heads pop off. Stronger bolts required?
There is certainly a lot of info in that little book.

Good call on the Loctite. :up:

In regards to the "stronger bolts," how do we know what bolts are used in th factory, and therefore which "aftermarket" bolts would be stronger?
 

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Discussion Starter · #42 ·
MattG said:
Interesting theory. I'll have to take a look at similar tabs elsewhere on the car. One thing to note though is that in each place, only one of the two locking tabs has been bent over. Why not bend both for twice the security?

In all fairness, there's one thing I can't rule out - there's a possibility that, when I took the car in for its 1k service, the tech bent the tab away, torqued that bolt, and bent the tab back. The only scenario I see a tech actually doing this, though, is if they notice the bolt has loosened already. Otherwise, if the green line is all lined up, why mess with it?
Good question. :confused:
 

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Discussion Starter · #49 ·
Chris said:
No, rear Passenger side.
The image you attached diagrammed the steering linkage, was this intentional?

Just saw the video, btw, great post. Thanks for the clip. The way yours broke makes sense as it was on the loaded wheel (not that it should have happened) but mine was on the inside wheel. So while the problem is the same, I cannot understand the physics behind what happened to my car, unless the bolt was so fatigued that the slight stress caused by driving over the reflector coupled with the stress of acceleration.

Thanks again,

Joe
 

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Discussion Starter · #51 ·
MattG said:
I don't fault them. This whole idea of having to check the torque of all the suspension bolts is frankly a little ridiculous; it's not something that modern automobile technology should require. Especially from a company that is known for its automotive engineering consulting business. Even the bolt in question whould not normally need to be checked, not with the locking plate there. It sounds like more of a manufacturing issue, not something the dealers should have been looking out for.

Whatever the case, it's frustrating to lose confidence in my car when issues like this come up.
I think that the dealers should become aware of this potential problem and should start checking these bolts.

When I get my car back you bet I'll be going through it with a fine toothed torque wrench :huh:
 

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Discussion Starter · #74 ·
MitchT said:
Don't think Lotus will even adress this issue or any relating to suspension torque, the dealer is not responsible for the car be speced each time it comes in for basic service.

The company announced " cars being used on the track need more than the normal maintence, above what factory manuals and scheduled maintence require", that is not a direct quote but it is the essence of the statement.

I know of no dealer/manufacturer ( Ferrari FFX excluded) who would support track activities as far as checking suspension nut/bolt torque, etc.

Tech inspection and scruiteenering of your car is your responsibility when you take it to the track.
With the exception of the occasional autocross, my car has never been in the track and I too am having these problems obviously. In normal circumstances we cannot expect the dealer to go through the car checking critical bolts, but this is not a normal circumstance. This problem can easily lead to a fatality, and it appears to be a defect in design. I have never had this happen to any other car that I've had despite some pretty aggressive street and mild track use.

I hope something happens at Lotus HQ, perhaps in the form of a recall, to address this issue.
 

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Discussion Starter · #75 ·
ChrisH said:
Another way that the hub (shim) bolts might be breaking is if they come loose, even a little (a millimeter or two), the hub will shift suddenly as the car shifts side to side in during handling. The bolt will stop the hub when it reaches the head, which will cause sudden hard shocks to the bolt and could eventually snap it. The shock force can be much greater than if the bolt is tight because in the tight case, it picks up the load gradually due to the tire dampening the side to side onset of force a bit. Even if only one bolt is loose, the flange (that bolts to the hub) can shift at that bolt location (it twists around the tight bolt). Hence, I wouldn't be surprised if the slightly loose bolt breaks before the tight one does. If the bolt manages to get very loose without breaking (too far out for the bolt head to be hit with a shock), then I would expect the secure bolt to break first.
This theory makes a lot of sense. :up:
 

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Discussion Starter · #76 ·
neckstrap said:
You guys are confusing me. I admit it's not that hard to do.:)

But, did the hex headed bolts that go through the rubber control arms break OR did the allen headed bolts that hold the tie rod link onto the hub carrier break OR both?

In either case, I cannot determine if the bolts are "graded". The best solution for breaking fasteners is to replace them with higher "graded" fasteners. I can buy grade 8 bolts like these at Home Depot for about $1.50 each. The allen headed bolts are a little more. But, why not replace them? And why hasn't lotus issed a recall to replace all of them under warrenty? Maybe we all need to start a writing campaign? This is a serious safety concern.

Paul
The Hex bolts, see the diagram I posted above and the pics Matt posted.
 

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Discussion Starter · #86 ·
NCZ06 said:
Have you filed a complaint with NHTSA?
Let me just say that I think Lotus is a great company with a great product. Perhaps the issue with some of our cars was an assembly oversight, it can be easily corrected (if the above theories on the cause is correct). My reasons for starting this thread was two fold: 1) find out what the heck happened, and 2) to inform others of this possibility.

On the whole I still believe our cars are safe, but, IMO, this is an issue that needs to be addressed with our cars. Five cars out of all the good elise drivers on this forum (assuming they are all elise drivers and all read this post - not likely - is still a lot of cars, especially when you consider the relatively low mileage of these vehicles and that fact that many (most?) elise drivers are not even members of this forum. For that reason I have sent a notice to the NHTSA so that this problem will be taken seriously, and hopefully prevent a potential fatality.

Thanks for all the info collected on this thread, it was very helpful.

Joe
 

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Discussion Starter · #105 ·
tesprit said:
Was there any sign of a thread locker (Loctite) on the threads of the original bolts?
I saw the bolts that broke on my car, and there didn't appear to be anything on the threads. Admittedly, I wasn't looking for it either though.
 
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