Guldstrand TA arm Zerk Spherical Joints

[TWINRAY]

These are metal not aluminum. Thought these might be the best alternative over rubber or poly. It's a street car and any added harshness wouldn't be an issue with me. Anyone tried these? Thanks as always, Fred

- Guldstrand Motorsport

 

[Hib Halverson]

Is this for a street or race-only application?

 

[TWINRAY]

Is this for a street or race-only application?

Hi Hib,

Street

 

[Vettehead Mikey]

How do they accommodate the camber changes as the suspension rises and falls?

Looks like a bad solution for a non-problem. The LAST bushing you would want to be rigid on a C3 is on the front of a trailing arm.

 

[TimAT]

Mikey, those are not rigid at all. From what I've read, they will move easier than the rubber thru nearly full travel. The only thing better I've heard of is to cut the end off the T/A and install jonny joints.

I suspect that they'll transmit noise and vibration right into the seat.

 

[TWINRAY]

Mikey, those are not rigid at all. From what I've read, they will move easier than the rubber thru nearly full travel. The only thing better I've heard of is to cut the end off the T/A and install jonny joints.

I suspect that they'll transmit noise and vibration right into the seat.

Something that gives the solid aluminum mounted C3 an even rougher ride .

In all seriousness, I have to find out more about the product hopefully from someone who has installed them. Majority concensus at this point is to use rubber and accept its shortcomings.

Thanks, Fred

 

[Vettehead Mikey]

What are the shortcomings of the rubber bushing?

 

[Hib Halverson]

Hi Hib,

Street

Been there, done that.

Don't put metallic spherical bearings in the ends of C3 trailing arms unless you want increased harness and greatly increased noise.

For street use either OE-type rubber or polyurethane. Rubber will give you the same ride and noise characteristics as stock. Urethane, will give you a slight increase in harshness and about the same noise. If you use Urethane, don't go cheap. Buy a top-quality, graphite-impregnated urethane.

 

[Hib Halverson]

What are the shortcomings of the rubber bushing?

For street use, there are few shortcomings unless the duty cycle is street/track and then the compliance can be a problem. For street/track duty cycles I suggest urethane.

For race only, the compliance becomes a big problem and spherical bearings are the best way to go.

For my hot rod 71 Coupe, I once had spherical bearings and I hated the harshness and noise. I now run a urethane trailing arm end bushing.

 

[73shark]

How do they accommodate the camber changes as the suspension rises and falls?

They're spherical. But I did always wonder about that question w/ the urethane ones. Seems like it would bind the suspension. Must be missing something.

 

[Hib Halverson]

In theory, they'd bind but in practice because the rotation of the arm is relatively limited, the urethane works quite well as a compromise between spherical bearings and OE rubber.

 

[73shark]

Kind of what I figured. One of those things where if we waited for the perfect theory, we'd never do anything. Thanks for the info.

 

[Vettehead Mikey]

For street use, there are few shortcomings unless the duty cycle is street/track and then the compliance can be a problem. For street/track duty cycles I suggest urethane.

I've always believed that the difference between rubber and poly can only be taken advantage of on the track- at or near the car's limit. No one should be driving that fast on the street. Poly has it's own set of disadvantages that need to be considered. I regret using them on my car.

 

[JohnZ]

These are metal not aluminum. Thought these might be the best alternative over rubber or poly. It's a street car and any added harshness wouldn't be an issue with me. Anyone tried these? Thanks as always, Fred

- Guldstrand Motorsport

Those are race-only parts - you don't want them on a street car unless you want to feel every pebble and hear all the bearings and U-joints.

 

[TWINRAY]

I sincerely appreciate everyone's input.
I've put them out of the equation - so now it's rubber or poly. Suprisingly, after 90K or so miles and being in the car for 40 years, the original rubber bushings still don't look too bad. Nuts came right off. Biggest advantage of poly at this point is that they would be easier for me to put in.