C4 trailing arms: Why some plastic/fiberglass models?

[69427]

I've seen some C4 trailing arms at swap meets that look like they're made of plastic and fiberglass. What was Chevy's reasoning for those?

 

[Twin_Turbo]

Those are 96 control rods.

 

[69427]

Those are 96 control rods.

What was Chevrolet's point in changing these on a one model year run? I don't recall anything in the C5 suspension that would use this type of geometry or material.

 

[big_G]

I think they are service replacements (only parts available).

 

[Twin_Turbo]

No, they are 96 exclusive and I don't think you can get them anymore either. They were a one your only deal and there have been reportings of problems with them (coming apart under hard use). Maybe it was GMs flirt with composite pieces. Maybe they were designed to bend a little who knows, just like that weissach axle in porsches with the bending links to reduce torque oversteer. I've only seen a pair of those things once.

 

[big_G]

The last few times I've had to replace them due to worn rubber bushings (on customer cars) I was sent the plastic ones from my chevy parts dealer. Maybe they went back to aluminum.