ShaneN.

I was just driving down the highway and heard something rubbing against the road so I pulled over and found this plastic piece wedged between a rear tire and the car, i touched it and it dislodged/feel free. I just looked up the part number and it looks like a lower control arm cover from my car somehow came off. I have no idea how that could happen except for my car was strapped down from the rear on a dyno using the control arms. I'm assuming that's it? I'm sure it was originally there for a reason but is there any reason to replace it or really worry about it?

Vladds

I would check the control arms.
Back in my Alfa Romeo 164 days, the rear aluminum control arms would get bent by the ratcheting straps.
They're supposed to check carefully where to attach the straps, not just hook from the easiest point.

ShaneN.

That's actually pretty scary, I didn't even think of that. I'll see if my Indy can put it on the lift tomorrow and inspect. Would it be obvious visually??

Funkwagen

I doubt the control arm is bent, the little clips that hold the plastic covers to the arms are fairly weak. Mine are currently held in by zipties because a number of the clips were broken on each side when I got the car.

roadkillrob

I have a BMW and someone strapped to one of the front aluminum control arms and about 6 months later it snapped on a relatively small pothole at low speed thank god - no one should ever tie a car down by a suspension component and I would avoid that dyno shop in the future as they don't know what they are doing if they did that.

As for the C63 that lower rear control arm is stamped steal I believe so it won't likely break in any case but it is possible they bent it.

As for the cover - I don't know exactly the point of it (maybe just protection from debris and or salt, not sure, but I am pretty sure it was designed and installed for a good reason, so I typically am of the opinion that it has a purpose and belongs on the car, regardless of how important the reason is.

Vladds

Look, I hope that I'm wrong about our cars and the control arms can't be bent with the ratcheting straps.
With the Alfa, that rear arm was a curved arm to begin with and all the strap did was to curve it more. You started to see the tire getting a nasty wear in a week, that's how you knew.

But when you think about it, in Europe, at that time, flatbedding a car did not seem to involve the ratcheting straps, in order to secure the car. I think I recall that those flatbeds had some kind of hydraulic chocks that pop up and secure the car by the tires. So the designers of the rear control arms did not anticipate that someone would grab them, in order to secure the whole 3200 lb vehicle (Alfa 164).

But, look guys I'm sorry to be a dooms day scenario person but, what if they ARE bent, but only slightly?.
That may explain why some guys rip through the front or rear tires much faster than others.
And it's not even localized to where everyone on the forum uses the fronts or the rears.
It's like in this community half burn through the fronts, 1/3 through the rears and some through none, just normal wear. Almost like some cars were grabbed by the front suspension, some by the rear and some transported correctly.
My car seemed to be out on the front passenger, as far as allignment, when I got it.

roadkillrob

For towing they should use either the wheel straps that wrap around the tire and or the bumper attachment points - it says it in big letters of pretty much every car to never use a suspension component as a tie down point - doing that is a rookie move.

ShaneN.

I'm about to head to my friend/Indy shop and have a look. He doesn't think you could see a slight bend visually though.he figures its better to check on a laser alignment rack


Just for my own knowledge to avoid this in the future, where do our cars get strapped down from in front and back on the dyno?

Vladds

Please post your findings and pictures too.

roadkillrob

I would want it strapped to the subframe outboard as far as you can go as that should be the strongest point, there are also companies that make mount points if you dyno a lot that will bolt onto the subframe or other areas. For the front just through the wheels should be fine, tow hook would work or to the subframe again, not a lot of force on the front straps, just needs to keep the car from rolling back off the roller.

ShaneN.

Took the car back to where it was laser aligned just a couple weeks back and he checked everything over and also checked the alignment and all appears to be good. Bought a new control arm cover for 17 bucks and popped it on. All is good.

roadkillrob

Good to hear - those are steel and pretty stout so would take a fair bit to bend it I imagine, but better safe than sorry. I would have them strap to the subframe as far outboard as they can get near where the suspension and body all mounts to the subframe, that should be the strongest place. I know Dynojet says either mount to the axle if a solid axle or to the control arms, but most modern cars have aluminum suspension components and are engineered to have the forces applied in very specific directions and forces applied in any other direction can damage things.