Upper lower rear control arms

[joepenoso]

rear upper lower control arms

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I've got a chevy 10 bolt in my 1971 442 with U shaped upper lower control arms and no rear sway bar.
I'm considering making changes but am not sure to go with stock boxed/rubber bushing mounted arms or something like this
http://www.ebay.ca/itm/271293378881?...T&_trksid=p398 (http://www.ebay.ca/itm/271293378881?ssPageName=STRK:MEWAX:IT&_trksid=p398) 4.m1423.l2649
it seems to have plastic bushings ................what up with that?
The rubber ones last a long time and are quiet..........plastic I'm not so sure.
Any experiences with rear control arm bushings is welcome
Thanks
joepenoso

https://static1.pt-content.com/images/pt/2013/10/popcorn2-1.gif

[UMI Tech]

How do you plan to use the car?

[joepenoso]

How do you plan to use the car?

driving on the street. No drags or gymghana
Thanks
joepenoso

[Classic Nova & Performance]

The bushings are polyurethane. They are a good bushing that doesn't deflect as much as a rubber bushing. My only knock on them is that they can be noisy/creaky. For a strictly street car driven application the rubber bushings should perform well & be quiet.

[joepenoso]

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I'm here just to see the benefits............rubber lasts a long time, (40Years)
No maintenance, no binding, runs quiet ........what exactly am I giving up for what benefit? This is for a street driven classic.
Thanks in Advance
joepenoso

Thanks
joepenoso

[Marcus SC&C]

That configuration of arms would be okay for a drag car but wouldn`t be my first choice for a street car. The trailing arms have to do a few things. They have to locate the axle under the car precisely, both laterally and in yaw. They have to control pinion angle under acceleration and braking and they need to allow the axle to move, unhindered throughout it`s range of movement not just vertically but in articulation. The stock arms are flimsy and the stock rubber bushings are soft and compliant. Because rubber bushings don`t rotate, they stretch/deflect they bind at anything but ride height. The effect is that the axle moves all over the place under the car. You can actually feel it if you try. It moves side to side, compromising tire clearance. It moves in yaw, steering the car like a forklift. It can be prone to wheel hop and it doesn`t do a very good job of controlling pinion angle. So, apart from working very poorly for a long time and being REALLY CHEAP to manufacture the stock arms don`t have much going for them. The type of arms you linked to are the old school "solution". If the stock arms are flimsy, make them rigid. If the stock bushings are too soft make them very hard. That should fix it right? Well...um...no. It just makes it different and gives us new problems. The squeaking and groaning mentioned above are well known issues and are the audible manifestation of the bushings binding up the suspension. Binding is bad. It`s preventing the suspension from moving freely and doing it`s job. This format of arm tends to bind the rear end up especially bad in roll, the chassis perceives this as added rate and causes the car to over steer, sometimes very abruptly, a condition called snap over steer. Again, this is bad. The solution are a growing family of arms that use grease able "flex joints" with spherical pivot balls encased in races made from polygraphite or delrin bushing material. These act like relief vales for kinematic binding. Because they use bushing material races they absorb NVH (noise, vibration and harshness) like a conventional bushings but they pivot freely is all directions like a spherical bearing. The enclosed, greased units hold up very well in dirty or wet environments, unlike exposed, un grease able metal bearings. The first to come out with this style of arms was Currie with their Currectrac series http://scandc.com/new/node/645 http://scandc.com/new/node/185 , they`re a little pricey but they`re among the strongest and quietest at the same time. One a budget I also like the UMI Rotojoint arms http://scandc.com/new/node/782 http://scandc.com/new/node/774 . There are a lot of others who have realized the advantages of this format but these two really stand out to me. The end result of picking the right rear arms is that the rear suspension with feel very smooth and precise with none of the slop of the factory system. Both handling and ride quality will improve.

[joepenoso]

WOW ...............................that was a good explanation!
joepenoso

[mitch_04]

Well...he did write a book :)

[joepenoso]

It shows
Thanks
joepenoso