Failed Trailing Arm
 

Has anyone ever heard of something like this? This is a rear trailing arm from a race car. I've been running solid bushings and mounts on the rear suspension for two seasons. Problem or coincidence? The front control arms failures are well documented, but I've never heard of this before. Another important inspection item!

Steve


http://forums.pelicanparts.com/uploa...1161606339.jpg

Was the car previously damaged in a collision?

I've never seen that of failure on a 944. I've heard that the best way to tell if your trailing arms or a-arms have cracks is to get them up to about 350º and the cracks start to show. Or x-ray inspection. But who has the money for that?

what kind of suspension are you running? Coil overs? or ultra thick torsion bars or both? My only thoughts are that it was a bum casting or the solid bushing is binding/forcing something out of wack to cause an eventual failure. first i've seen.

Dang!!!!

Altogether in the rear: spherical trailing arm bushings, solid torsion tube carrier bushings, solid torsion tube block mounts, 525 lb coilovers, no torsion bars, Leda shocks, -2.5 degrees camber, 15x8" Fuchs, Tarret sway bar.

Looking at the crack, it doesn't look like a fatigue failure that happened over a long period of time.
It looks like the car got a serious hit and at that moment the thing broke in half. Did you get in a collision on the track?

Not to cause the control arm to break, but after the break, yes. I only know from the corner worker's report... The arm broke on turn-in. The break and impact with another car happened so fast that I had no time to appreciate that I lost one corner of the car.

Steve