trailing arm reinforcement, I know its been talked about but.... Options

[736conver]

Ok as some of you might know I'm about to install the needle bearings in my trailing arms. So I am preparing the arms before they arrive so I'm ready. I come to find out that the passenger side is bent. Has a little bulge in it. No problem I will just head to my 30foot trailer full of parts, that no one wanted to buy, and get a different one. Same thing on 2 others. So thats three passenger side arms that are bent or tweeked. Just to make sure its not a fluke I check the driver side arms and find out I have two bad ones out of five. I am almost positive these all came from 4cyl.

So what can be done to avoid this. Everyone seems to think the reinforcement kits are useless or overkill. But the arms keep bending......

Thoughts..............ideas...........


Brian

[Jeroen]

So what can be done to avoid this.

Don't kiss the curb while going sideways (IMG:style_emoticons/default/confused24.gif)

[morgan]

when do you want me to buff out your car
John

[Verruckt]

Doesn't someone make aftermarket trailing arms that are stronger than the originals?

[736conver]

John,

Need to make my car a roller before buffing it out. Unless you make house calls.


Brian

[brant]

I'd love to see a picture of a bent arm...
brant

[Joe Bob]

AFIK, the re-enforcement is for high torque flex prevention.....they will still bend if you smack a curb.

[736conver]

I tried to take a picture for the post. But you just dont see anything with the camera. Its too hard to notice the difference. Its kinda of a sight and feel thing. A straight edge helps too.

[736conver]

Here's a pic of bent arm with straight edge on it.

[736conver]

Heres an unbent arm.

[brant]

cool thanks for the pictures...

you mentioned a kink..
Is there a kink.

what I'm getting at is could there be a chance that the arms are shapped different due to build tolerances or is it definitely bent.

brant

[736conver]

That picture of the bad arm is the straight edge on top of the bulge, kink, whatever you want to call it. Thats definitely not a factory thing build thing. That is suppose to be the flat side of the arm.

[eeyore]

I'm with Brant on this, here's my theory...

When bent, one surface of structure must stretch (same amount of material, more distance) and the opposite surfuce must crumple.

The face you are checking is the outboard side of the arm, right? The most likely way an arm will get bent is by sliding into a curb, an outside-inside motion. Therefore, the outboard side must get longer, the inboard side will get shorter. Bending a structure like that would cause that face to pull in, not push out. Unless there is some interior member.

Check and compare the top and bottom faces of both arms too. They should be tweaked as well. It looks as if the seams started life out straight, are the still straight?

[eeyore]

Here's what I'm saying, with a picture. (Granted the trailing arm is more complex)

If you take a piece of channel and bend it, the face of it will want to stay as close to the green line as possible. That causes the face to become convex between the top and bottom corners, and the surface never protrudes beyond the edges. Therefore, although there could be curvature, the bump indicated by your straightedge shouldn't be there if the trailing arm was bent in an accident (normal use?).

Also, the corners of the trailing arm don't seem to indicate the same level of (or any) distortion that the straightedge shows is going on at the face.

[Slowpoke]

Not the way I would check for a bent control arm. I would make a two bushings to fit in the front of the control arm (where the rubber bushing are now) and insert a straight steel rod theough the bushings. Then bush the axle bearing surface and put a straight streel rod in it. Then check if the two steel rods were in the same plane. Anything else seems like guessing to me.


That looks like heat distortation from welding on the controll arm to me.