rear trailing arms ???

[petty43fan]

do any of you guys know of aftermarket reat trailing arms for a 91 gp? the stockers look weak and i was thinking about changing them. any input on this would be appreciated, thanks

[GutlessSupreme]

http://www.gmpartsdirect.com

 

12498649

 

$32.37 + S&H

[petty43fan]

thanks

[5speedz34]

There is also BMR they make one's with poly bushings in them. But they are expensive...

[J]

too expensive!

[bigdman]

if you have access to a welder you can make a set, i did for my cutlass and i dont think they will ever break.

[Intlcutlass]

Your stock ones are plenty strong....

 

The problem is rust. Once rust has eaten it's way through most of the arm, sure it's gunna break.

 

The ones from GMPP are powdercoated, so they should last ..forever.

 

But if your factory set is in decent shape.... take em off and POR-15 them , or zink them, and paint them.... They will last a looong time.

[5speedz34]

too expensive!

 

Poly!!!!

[joey b]

http://www.gmpartsdirect.com

 

12498649

 

$32.37 + S&H

 

That lists as being for a 2000 and newer. Is it the same fit?

[petty43fan]

thanks for the imput guys.

[GutlessSupreme]

Yes.

 

x2

[per0781]

i know this is for f-bodys, but it talks about poly bushings:

 

http://www.geocities.com/motorcity/1701/bushings.htm#Is%20Polyurethane%20good

 

Suspension/bushing bind:

 

Bind occurs when the the pivot points of the suspension cannot move as intended. As it relates to third- and forth generation F-body car, bind is when the pivot points do not move smoothly under load (stiction, or static friction) or when the suspension moves outside its (or one or more of its components) design parameters (in this case, range of motion restricted by the lack of compliance in the polyurethane bushings)

 

Under hard cornering, bind can create dangerous handling conditions.

 

Polyurethane bushings:

 

Polyurethane (or 'poly' or 'plastic') bushings are popular, as they noticeably 'tighten up' the suspension, and the aftermarket arms look cool, but most purchasers to not understand how they work, or the problems they create. This is an old issue, but the recent popularity of poly-equipped aftermarket control arms has drowned out the proven drawbacks of this material, including stiction, binding, squeaking, harshness, and need for regular greasing.

 

Poly is used in place of the rubber portion of the factory bushings. Unlike the rubber bushings, they are not bonded to the inner and outer sleeve, and movement of the control arm will cause the internal surfaces of the sleeves and bushing to slide to accommodate the shearing forces. The two main issues:

 

Stiction (Static Friction): Under light loads, they may squeak as the arm moves. Regular greasing reduces the squeaking, but under high loads, especially cornering on uneven pavement, the "sticky" properties of polyurethane causes the plastic to "grab" the steel liner, adding harshness to the ride, as the steel sleeves can't slide smoothly over the poly bushing surfaces. At worst, when the suspension then cannot move as designed, the handling of the car will be affected and this can create unexpected and dangerous oversteer.

 

Binding: To complicate matters, the trailing arm type rear suspension in the late model f-body cars has bushings that flex or 'deflect' as a normal and required part of their function. As the solid 'live' axle moves to comply with an uneven surface, it (and the LCA mounting points) rotate in relation to the chassis.

 

1. The factory rubber bushings in the lower control arms accommodate this rotation/twist by design;

2. Poly bushings force the lower control arms to twist.

3. Tubular or boxed control arms - with poly bushings - force the LCA mounting brackets on the chassis and axle to bend;

4. Now that the car relies on twisting metal for suspension, it may at times bind, as the axle cannot move smoothly comply with bumps. The resulting oversteer condition can result in loss of control on high speed corners - not what you want in a high-power rear-drive car.

5. Subframe connectors (SFCs), added to brace the chassis, reinforce the forward LCA mounting points, but the twisting force is still there on the arms and rear mounts; poly bushings may seen to ride firmer after the addition of SFCs due to the more solid mounting of the LCAs.

6. Even for lower speed handling, the poly bushings increase the rear roll stiffness - something you should be tuning with the spring rates and sway bars.

7. Greasing the poly bushings does not help this issue.

 

Dispelling other myths:

 

Why isn't Polyurethane a good bushing material?

 

* "...virtually no deflection..." (cut and pasted from their web page). As mentioned above, the engineers that design these cars employ rubber bushings because deflection is required in most locations.

* "But I lubed them well, or I used Polygraphite® bushings": You are asking the poly material to act like metal bushings, and it can't. Lubing will temporarily reduce the squeaking and stiction. The graphite-impregnated versions are just 'pre-lubed', and once the graphite has worked its way out, the bushings will squeak and require regular lubing like the others. Lubing does nothing for the binding problem.

* "They get quieter over time": Poly will cold-flow, meaning it will deform under pressure and not return to normal, as it lacks the elasticity of the rubber bushings. Over time, they will loosen and then rattle. Check out the shape of your swaybar's poly end-link bushings after only a few months. This cold-flow issue can also lead to alignment problems on the front control arms, as the bushings deform.

* "But everyone sells them". Well, yes, and the manufacturers of Slick 50 and the makers of 'ultra/super white' bulbs could line up a long list of satisfied customers, but what would that mean?

* "Testimonials are everywhere!" but they don't convey the facts. Don't' believe everything you read in a glossy brochure or web page. Ever watch those late night infomercials? Like those other automotive miracles, wouldn't the large manufacturers pick up on this stuff if it really lived up to all it's claims?

* "But lots of other people use them!" As mentioned above, trailing arm suspension requires deflection in order to work, and when poly bushings are used, the required deflection is still there -- in the bending of the arms, mounting points, and flex of the rear tires. This is why these bushings appear to work fine for street applications.