Lower rear control arms for 96 RMW

Does anyone make these anymore? I need some and the NOS are long gone.

try these.. old sites. no guarantee of parts, but it's a start for you.

http://www.metcomotorsports.com/proddetail.asp?prod=MCA0012&cat=94

http://www.lmperformance.com/c/1/3.html

These are what I have...both upper AND lower:

http://www.umiperformance.com/catalog/index.php?main_page=product_info&cPath=4_76_81&products_id=92

Just the lowers:

http://www.umiperformance.com/catalog/index.php?main_page=product_info&cPath=4_76_79&products_id=95

I got a NOS set from Hamilton Chevy on eBay last year when one of mine broke.

If you want to run an SS/9C1 rear swaybar, PMT (pure muscle tech) will fab you a set of rear lower control arms at a very reasonable price. They are on ebay and at http://pmtfabrication.com/Category/5-78-96-impala-ss-caprice.aspx. If you don't want or need a swaybar, UMI is a great company to deal with. The PMT and UMI arms are virtually identical.

Do yourself a favor and skip the stamped stock control arms.

lakeffect wrote:

try these.. old sites. no guarantee of parts, but it's a start for you.

http://www.metcomotorsports.com/proddetail.asp?prod=MCA0012&cat=94

Metco has what you need

jasonlachapelle wrote:

Do yourself a favor and skip the stamped stock control arms.

What am I missing here? I'm sure it's happened, but I've never heard of any stock arms breaking, failing or rusting out. They also are the lightest arm you can put back there. Excess weight just makes for worse ride quality. For a stock vehicle, with no sway bar, you can't DO better, can you?

https://gmlongroof.4umer.com/t5366-anyone-want-to-see-some-catastrophic-control-arm-failure

Oh, hi there.

Hah! It would figure that the first breakage I read about would be off a WAGON forum.
lol

We try harder.

jimbeau wrote:

jasonlachapelle wrote:

Do yourself a favor and skip the stamped stock control arms.

What am I missing here? I'm sure it's happened, but I've never heard of any stock arms breaking, failing or rusting out. They also are the lightest arm you can put back there. Excess weight just makes for worse ride quality. For a stock vehicle, with no sway bar, you can't DO better, can you?

Calling the stock arm marginal would be generous.
They have broken and rusted out in the past. The cheap, U shaped, stockers are so flimsy you can crush them with your bare hands. I'm sure you can imagine that under high torque conditions they can and do twist which leads to wheel hop. Ever punch the car on a rainy day and feel it shimmy and shake like the suspension was made of plastic forks held together by rubber bands ?
I'm sure a lot of people will get by fine with them, and it's not necessary to rush out to buy upgraded arms. At the very least I would box the stockers and put in new bushings to lessen or eliminate wheel hop. However if someone like the OP needs to replace his arms it would be foolish to buy new GM units with 16 year old bushings when much better alternatives are out there for less than $200 that will allow you to mount a 9C1 swaybar (generally free). Unless of course you're building a concours restoration.

So, yes. You can do much better. I'd be surprised if you could do worse. Maybe the 1st gen BMR arms with the ridiculously undersized bushings.

I have never heard anyone with a stock B body complain of wheel hop. You are recommending a heavier and more expensive option where no need exists, if a pair of stock arms is available to someone who doesn't plan on a swaybar or significant engine upgrades. I disagree with you. People who have collectively logged millions (billions?) of trouble-free miles would also disagree with you. Unneeded dead weight is not a desirable thing.

I can see both points, really. For the average wagon owner/driver, the boxed or extended length are overkill.

If anyone wants to put on chrome/moly-titanium-vanadium parts on his or her car, they still have the right (maybe... restrictions might be hidden in the 'health care' bill) to do it! Have fun! That's what the hobby is all about. Just don't paint perfectly-fine-for-their-application parts as just plain unworthy, because it isn't so.

Bam. Good point.

Hell, they made it 20 years. I think that's good enough for me, lol.

I went with new GM lowers ( but Jason is right..didnt think about the bushings being old..they looked mint though...humm) I have the rear bar brackets that "box" the arms in, not the plate and metal tube style.

Granted I dont plan on autocrossing the thing, but it sure handles nice. If I went with a larger bar, I would likely upgrade LCAs.

OP, there's a set for sale on ISSF. I've bought lots of stuff from Mike, he's great to deal with. Mike from Hamilton Chevy, another ISSF member sells them on ebay

jimbeau wrote:

I have never heard anyone with a stock B body complain of wheel hop. You are recommending a heavier and more expensive option where no need exists, if a pair of stock arms is available to someone who doesn't plan on a swaybar or significant engine upgrades. I disagree with you. People who have collectively logged millions (billions?) of trouble-free miles would also disagree with you. Unneeded dead weight is not a desirable thing.

You had never heard of anyone breaking a lower control arm either.. Yet GM recalled 150000 B-bodies because of the propensity of the LCAs for cracking at the swaybar mounting points. Granted, the wagon doesn't have a swaybar, but I've had one fail a wagon with 118000 km with no swaybar. The stock stamped LCAs are just like the stock LT1 valvesprings: just barely good enough to get the job done. You're right, people have logged a lot of miles on both components, but IMO they are unsat.

My point wasn't that everyone should rush out to buy new aftermarket boxed LCAs. My point is that if you're confronted with replacing your stock LCAs, and you can pay $100 for NOS stock ones with 15 year old rubber bushings, or $159 for boxed aftermarket ones with greasable bushings that will allow you to mount a 9C1 swaybar, it seems like an obvious choice. I don't know how much wheel time you have on a B-car with boxed LCAs but they definitely do not worsen the ride quality. I could weigh both units to show that wheel and tire choice will have a greater impact on unsprung mass.

You are attempting to minimize everything I said here and maximize your 'points'.
Fine. You are right. I am wrong. Rest easy, now.
By the way, every part of our wagons met government crash standards. Safe.

Good rebuttal, jimmy. Well thought out, and detailed arguments.

BTW, cars didn't use to have airbags, ABS, or seat belts. Those cars met government standards, too. Times change, technology improves.

jimbeau wrote:

You are attempting to minimize everything I said here and maximize your 'points'.
Fine. You are right. I am wrong. Rest easy, now.

That's basically the definition of debate. It's unbecoming to pick up your proverbial marbles and go home because someone disagrees with you...

jimbeau wrote:

By the way, every part of our wagons met government crash standards. Safe.

What does that have to do with anything ?

jayoldschool wrote:

Good rebuttal, jimmy. Well thought out, and detailed arguments.

It's code for: "I give up. He isn't going to concede anything at all, to save face or some other reason."
Nobody has run aftermarket arms for well over 100k on real roads in real weather, to see how they hold up.
It's always easy to be a 'shiny, pretty, new parts' booster. Jay, if you agree with Jay at this point, more power to you. It's your car.
If you are really spooked at the thought of stock control arms, or old safety standards, etc., you would never hop on a motorcycle or even ride in an older classic car, for Pete's sake.

or even get enthused about a "dangerous-by-today's-standards" station wagon (without full-curtain variable impact airbags, seatbelt tighteners, etc.).

jimbeau wrote:

It's code for: "I give up. He isn't going to concede anything at all, to save face or some other reason."
Nobody has run aftermarket arms for well over 100k on real roads in real weather, to see how they hold up.
It's always easy to be a 'shiny, pretty, new parts' booster. Jay, if you agree with Jay at this point, more power to you. It's your car.
If you are really spooked at the thought of stock control arms, or old safety standards, etc., you would never hop on a motorcycle or even ride in an older classic car, for Pete's sake.

I'm not sure why you brought crash safety up or why you're getting so wound up about nothing. Did you misread unsat(isfactory) as unsafe ? Car forums are supposed to be about discussion. The readers can ultimately decide to do anything they want with their money.

FWIW, I purchased my 1st set of aftermarket control arms used with 45k miles and put over 160k km on them on my PPM sedan daily driver between 2006 and 2009. I put it through several winters in Quebec and in the Prairies. The car was never garaged. I took pictures of the underside before selling it (I'll see if I still have them on my laptop tonight) and the powdercoating did a great job at inhibiting rust and the poly bushings hadn't deformed. Last I heard, it had changed hands twice and accumulated another 100k km. I didn't encounter suspension binding, handling improved and there was no degradation of ride quality. Insignificant compared to the sum of the mileage run by stock B-cars but enough to convince me.

jimbeau wrote:

Nobody has run aftermarket arms for well over 100k on real roads in real weather, to see how they hold up.

I have (almost...93K). The PO jacked up the car by the control arm and bent it all to hell before I bought it with 74K on the clock. It now has 172K on it now and I can tell you WITHOUT A DOUBT that my UMI arms have caused ZERO problems.... as long as I grease them with every oil change. You know, when you are supposed to lube the front end parts and U joints....

Yes, the OEM parts were designed with a certain amount of flex, or "wiggle room" and the aftermarket has none. What I CAN attest to is that when I was towing a 6'X10'x6' tall enclosed trailer with 3500 pounds of junk in it, I had very little shimmy.


.....and the Pinto was deemed safe and met all safety standards of the time....until it didn't.

jimbeau wrote:

I have never heard anyone with a stock B body complain of wheel hop. You are recommending a heavier and more expensive option where no need exists, if a pair of stock arms is available to someone who doesn't plan on a swaybar or significant engine upgrades. I disagree with you. People who have collectively logged millions (billions?) of trouble-free miles would also disagree with you. Unneeded dead weight is not a desirable thing.

Have you put any heavier, more expensive, and better quality parts on your car? Lots of people are happy with stock parts on their cars. Some people want more. The people who want more tend to post on internet enthusiast boards.

Just as an example, most people are happy with the stock battery cable and headlight harness. I bought the aftermarket upgrade, with heavier and more expensive cables. The extra light output isn't necessary, but I enjoy it.

I put more expensive parts in my suspension too. Most people don't seem to mind the stock setup. I enjoy having the wagon go where I point it.

Yes, I have. But that was not my point.
My point was merely to let the many 'stock' wagon drivers here (and elsewhere) know that they don't need to fear the factory control arms. Only one 'failure' has been shown here so far... out of untold miles driven.
To any newbies here: The factory put these arms on these cars for 20 years straight. If the ones on your car look good (no bends, cracks, excessive rust, etc.), they will continue to serve you well. There ARE design superiorities of stamped arms over welded arms, but I see no benefit to discussing them here, now. This has not been been a good, straight, engineering discussion.
That is all.

My arms had approximately 115k on them when they failed. A perfectly acceptable service life.


Robert (or anyone else), have you ever towed with stock arms? Interested in feedback in that department.

No, but when I turned the wheel from 9-3 quickly, I could "wiggle" the ass end. Car pivoted somewhere near the front seat/dash. After the arm swap the pivot point was the back seat. Add the Monroe SS and airlifts and there is no shimmy.... just roll

Would the shimmy still be there if the arm was not bent? I don't know.

jimbeau wrote:

Yes, I have. But that was not my point.
My point was merely to let the many 'stock' wagon drivers here (and elsewhere) know that they don't need to fear the factory control arms. Only one 'failure' has been shown here so far... out of untold miles driven.
To any newbies here: The factory put these arms on these cars for 20 years straight. If the ones on your car look good (no bends, cracks, excessive rust, etc.), they will continue to serve you well. There ARE design superiorities of stamped arms over welded arms, but I see no benefit to discussing them here, now. This has not been been a good, straight, engineering discussion.
That is all.

No one said they should be afraid of the stock control arms. You brought up control arm failure. I don't think anyone reading this thread would gather that they need to immediately go replace their stock LCAs. If any newbies are reading it and are worried, let me reiterate what Jimbeau said: No one is advocating you replace your stock LCAs for safety reasons if they appear to be in good condition. The recall on the control arms affected cars with swaybars (they revised the mounting). If you have a few bucks to spare, a new set of rubber bushings [Moog K6116 (2 kits per car)] will go a long way towards restoring your handling/ride being that it's 15+ year old rubber.

Do you honestly think it's more likely GM put that type of control arms on the B-body (and many others) in the 1970s because of its design superiority or because that type of arm costs less to manufacture and got the job done (i.e. it's inherently flexible) ? We're talking about a design from a period of time where cost cutting and putting out a product that barely gets the job done was what the Big Three were all about. I haven't talked to any B-body chassis engineers, but what do you think a reasonable design life cycle was back then ? enough to get the car just out of warranty ? 60k miles ? 100k miles ? I don't know. In the mid-90s the engineers at GM designed the G-platform with a planned life cycle of 150000 miles. I don't know how many stress cycles they can take, and it was never the point of this discussion.

There is no better place or time to discuss the design superiority of stamped control arms. Don't be like your favourite supermod and keep your knowledge to yourself. Stamped arms absolutely do have certain qualities: They are cheap to mass manufacture and less prone to binding, especially with the rubber bushing. They are torsionally compliant, but they flex and are pretty weak. The high loads from autocross or dragstrip use (or "spirited driving") can be more than they can take. You end up having a component acting like an undampened spring whose motion can't be reliably controlled. Add to the mix the stock rubber bushings that are so squishy they lateral and/or vertical motion of the axle (not good). However they need to flex IOT allow the axle to pitch and roll without binding. That's why most people either keep the stock stamped uppers with boxed lowers with the "regular" poly bushings or go with the roto-joints on the axle side if they go with all 4 aftermarket control arms. The uppers are shorter and are at a greater angle, so the torsion applied to the links is greater. Boxed control arms help accurately control suspension geometry in ways that the stock stamped arms can't, which improves handling.

Note: You need a special tool to change the rear upper control arm bushings. I've never seen it available for rent, so if anyone needs it, I'd be more than happy to loan it out if you cover the shipping. PM me.

Krzdimond wrote:

Would the shimmy still be there if the arm was not bent? I don't know.

The shimmy/no-shimmy was probably because of the change from rubber bushings to plastic.

jimbeau wrote:

Krzdimond wrote:

Would the shimmy still be there if the arm was not bent? I don't know.

The shimmy/no-shimmy was probably because of the change from rubber bushings to plastic.

I agree.

Shimmy Shimmy Ko Ko Bop

This here article is interesting, because it involves control arms that are castings, not stampings. They also don't have tons of miles on them:

http://www.detroitnews.com/article/20120811/AUTO0103/208110393/GM-recalls-more-than-38-000-Impala-police-cars?odyssey=tab|topnews|text|FRONTPAGE

This is why I have the firm belief that good quality stampings are a safer long-term part for cars driven in real life. Stamped parts have 'give' or 'crumple strength', which gives them an edge over rigid parts in the years of flexing and hammering that occur in normal, daily driving in all seasons. Castings or welded parts have no give. They can fail 'catastrophically', meaning they will break in two, with little or no warning. Stampings will fail, but hang together long enough for you to wrestle your ride to the exit or curb.