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Lower Control Arms & Sway Bars - Upgrades

6115 Views 59 Replies 11 Participants Last post by  Johnp410, 
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I have been looking at Lower control arms and sway bars to try and control some of the body roll and rear end noise in my car. I have FE2 suspension (OEM) and was looking at putting beefier rear and front sway bars in the vehicle. Read on some old forum posts that a fat rear bar will likely crack the original lower control arms so now I am looking at those as well.

UMI seems to be a great place to get LCAs from... I did see that new POLY bushes will make the car ride stiff compared to the OEM rubber ones. Is this the case? I'm looking to keep the ride as squishy as possible, but remove some sway and roll in turns/corners.

Anyone have any experience with the standard UMI bars? What about the Roto joints? Would those make the car ride more smoothly compared to 2 POLY bushings? Links below to see what I am talking about. The Roto joints look really interesting, but can't find much about just a streetable car that's driven gently most of the time.

www.lmperformance.com

UMI Performance 3615 - UMI Boxed Lower Control Arms - GM B-Body

UMI Performance UMI Boxed Lower Control Arms - GM B-Body - 3615
www.lmperformance.com
www.umiperformance.com

1978-1996 GM B-Body Boxed Rear Lower Control Arms- Poly/Roto-Joint - UMI Performance Inc.

UMI’s boxed lower control arms utilize our Roto-Joint technology for a bind free performance and quiet comfortable ride quality. The
www.umiperformance.com www.umiperformance.com

Also, it's been recommended that I check out BMR sway bars - their rear bar is fat and should really control the back end pretty well. Front bar is smaller, but the set would probably even the car out well (replace both).
www.bmrsuspension.com

Free Shipping on all BMR Suspension packages!

Leader in High Performance Suspension and Chassis Products For American Muscle Vehicles.
www.bmrsuspension.com www.bmrsuspension.com

Thanks for your thoughtful advice!
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Very helpful link.... Some different opinions in there... Also saw a thread regarding a sway bar brace (looks like for the front).

Where in the world did you find all that stuff so cheap?? I want in on those deals! :p

These look interesting too, although probably not needed with my setup: 1978-1996 GM B-Body Lower Control Arm Relocation Brackets - UMI Performance Inc.


Also came across this front sway bar brace, which I read about in a thread and @Marky Dissod has mentioned to me: camaro,trans am chassis, 3 way sub frame connectors, 2nd gen frame
Are there any rear braces like this that work with the sway bar? I've seen Buick bars, but then I would have to weld a bar in there (could be done, no skills/tools for it).


So it seems like people DON'T like the all poly setup like I mentioned. Someone in that thread mentioned doing 1 roto joint and 1 poly and then @95wagon has 2 rotos. I'm looking to keep the car nice and quiet inside and not affect my suspension over bumps at all. Stiffening everything up in turns is the goal. UMI makes 1 and 2 roto joint LCAs... Have you had any issues using 2 and keeping the suspension soft (I know it wasn't your goal when installed) and quiet?


The F body brace would fit on our vehicles, it seems and would be a good setup with an aftermarket front brace, especially BMR (thick).



So I guess I am back to all poly is a bad idea. 1 Roto or 2??
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delete. duplicated
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green hose said:
View attachment 200172 3CFAB with upper adjustable control arm,the poly bush squeak big time.
Click to expand...
So avoid the all poly bushing... What about 1 poly and 1 roto or 2 roto?
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Fred Kiehl said:
I have poly bushings in the front of my wagon, They are quiet, and do not seem overly harsh. I greased them before installing. I put rubber ones in the back in an attempt to make launches a little softer. I do not know if there are any benefits to doing that.
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Thank you. Poly bushings on the front sway bar?

I'm concerned about the harshness as mentioned and noise. Do you have any experience with Roto joints?
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Fred Kiehl said:
Anti-roll bar too.
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So like the F body Pro Touring brace I linked above? It's for the front only.


Marky Dissod said:
0. Unlike the front frame and front swaybar, the rear sway bar and the rear frame brace are too far apart from each other to interact with each other.
1. A rear frame brace can be a tow hitch, or anything else that reinforces the connection of the rear frame horns.

2. Again, physically and conceptually separate from a tow hitch or any other sort of rear frame brace, consider:
a. Dick Miller Racing Rear Triangulation Braces
b. making the swaybar act between the frame and the axle instead of against the rear trailing arms
Click to expand...

Need do look into what scot said about a 1/2 steel pipe... It's linked in one of the threads above; would be an easy fix.

I haven't found a good (read easy) way to attach the swaybar act on the axle.




That said, I was hoping @95wagon would chime in with the double Roto joints on road noise in the cabin and ride quality. I am planning on calling UMI to discuss with them the differences between the various options they have.
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@95wagon What is your opinion on the F body touring brace like I linked above? It links the front horns together and the sway bar ties into it?


Also, do do 2 Roto joints sound/feel in the suspension for your LCA? Are they noisier than 2 rubber pushing or 2 poly bushings?
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Fred Kiehl said:
I have poly bushings in the front of my wagon, They are quiet, and do not seem overly harsh. I greased them before installing. I put rubber ones in the back in an attempt to make launches a little softer. I do not know if there are any benefits to doing that.
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I spoke to UMI on the phone and the gent was very helpful. He said that the all poly setup as long as they are greased properly (both sides of the bushing) and the zerk joint, they should not make any noise.

My 25 year old rubber bushings are almost certainly shot for the LCA.... That said, the poly will be harder than rubber. You think I won't even be able to tell a difference in stiffness of ride quality with the new poly arms/bushings?

All I am seeing are benefits for these stiffer arms... correct?
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91ss said:
Having gone to poly lowers on the 91, I can say, it's subtly different for different road conditions than rubber. For slow moving up down dips, they actually feel softer as there is no bushing twist to add 'spring rate'. Other conditions like pot holes where the tire is also jarred rearward during the impact, they feel more harsh. So really depends on what you roads are like where you live. Same setup maybe be horrible one place and perfect somewhere else.
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That's where I am stuck. If I want to add a stiffer sway bar, I'm going to have to upgrade the LCA.... But the new ones all come with poly bushings.

I have a tow pack so my front bar is already 30mm and rear bar is 26mm straight from the factory.


The rubber bushings are no doubt TOAST. So how soft will they really be right now? Will I even notice a difference between new poly and old rubber? Roads here aren't glass like FL or AZ, so we do have potholes. However, I go back to age of bushings and what the difference will be real world.


Any ideas on that front?
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91ss said:
I've ran with stock arms and the 1.5" HA bar most of the 91's life. Close to 200k just as a reference. It's all how you treat, or abuse the car...
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Caddylack said:
It is NOT necessary to upgrade your LCA's just because you upgraded your sway bar. Like 91ss said, it's all about how you drive the car.

If you are going to be tracking the car, you need to upgrade the LCA's, as they are one of the known weak points in our suspension. For a daily driver, I would not hesitate to use a set of new OEM arms. You will be fine.
Click to expand...

I see on both fronts here guys. So tracking it will almost certainly cause the system to fail with a new sway bar.... No track and massive stress, the new sway bar will be fine with OEM LCA (new).

So back to a point: New (OEM) LCA will certainly improve the ride quality as they are newer and new bushings. Is it worth the sway bar upgrade? As @Caddylack and I have been discussing via PM, my car already has thicker sway bars from the factory.

ADD: @Caddylack where do you even get a new OEM LCA? I can't find anything on RockAuto or Autozone....
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Caddylack said:
So, what you're saying is that the (older) uppers will not bolt to the 94-96 axle housing bushings properly? Swapping the bushings would solve this problem?

If those Dorman uppers don't work, then that would also be news to Brent.

The lowers should be a non-issue, as they are listed for 1992 Roadmaster.
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95wagon said:
you might have misinterpereted my post.
At one point in this susps life span all 8 bushings were interchangeble.
When they became metric in later years, the housing mounted bushing did not change.
Then 6 bushes were the same , two were not.
Look at the hardware on our cars.
The bolts in the housing bushings are smaller dia than the rest.
Can't tell you the exact year change.
All 91-96 though, 14mm in 6 postions ,smaller dia in top housing.
Click to expand...

Thanks for the good post. Incredible find on the OEM (sorta) LCA.

So are we saying that the LCA would fit right in to my car if I decide to go that route?


I need to verify my sway bar size, which I can hopefully do soon. Yes the poly spectrum makes complete sense. That and stiffening the frame a bit as well. I would like to look at how bad the LCA bushings are... That will also sway my decision (LOL).
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Caddylack said:
Haha... This just happened the other day!

I knew exactly what you meant, and we are on the same page.


That lower control arm is a direct bolt-in for your car.

The upper is almost a direct bolt-in, but will require some sort of adjustment (like changing the bushings on your axle housing).
Click to expand...

Thank you for posting.


I just wanted to drop by and say that I verified the front sway bar diameter on my car is 30mm... V4P Tow pack car, to keep things updated.

I was too tuckered out to verify the rear after working on the front suspension.
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resurrecting from the dead. My inserts and bolts that hold the sway bar into the LCA are completely toast. Bolts broke and the insert is messed up.

So I’m back to the drawing board. It looks like Dorman 520571 doesn’t have the insert to hold the sway bar in place. I think I’m not going to be able to make that work.

I’ve come across BMR and UMI LCAs at the same price… fully boxed, both poly bushings with grease fittings.

For what it’s worth, BMR discusses “internally fluted bushings”

see quote:BMR’s bushings are internally fluted, which allows grease to evenly coat the inner sleeve and keep the grease in the bushing under high loads. These flutes also direct grease to the outer edge of the bushing, keeping the thrust surface lubricated. This efficient lubrication ensures quiet, reliable operation over the life of the bushings.

Is there One I should favor over the other? Would like to get these ordered and installed very soon.
Thanks a million!
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Marky Dissod said:
If it turns out that it's easier to order BMR or UMI lower trailing arms, than to order 9C1 lower trailing arms, I get why you might wind up with BMR or UMI lower trailing arms.
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Right.... I have looked around and it doesn't seem to be possible to get the 9C1 arms.


Any ideas on the BMR vs UMI?


BMR's fluting sounds interesting...
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1slow96 said:
Sounds more like "marketing" to me....
Click to expand...

Spoke to BMR on the phone. They have internal flutes to help distribute grease more evenly. Whether it works or not is up to you to decide.


I did find out:

The F body arms use rubber bushings and they are the same as the B body bushings. BMR can and will sell you rubber bushings for the B body and you can use them as a 1:1 fit.


Conclusion: I purchased the BMR trailing arm kit (comes with sway bar bolts and lock nut and poly bushings), rubber bushings added to kit, and the hardware kit to mount the trailing arm to the frame/axle.


Will report back when I get everything and let y'all know how it goes.
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toonwarrior said:
So I could swap the poly bushings on my extended BMR arms for rubber?
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Yes, believe so. They should be the same as the standard length.

I was instructed to use a 3/8 socket extension and gently tap out the sleeve.
The poly bushing is a 2 piece setup. Remove poly sleeve and then grease the sleeve/inside of rubber bushing.
Insert rubber bushing in control arm
Use deadblow hammer or rubber mallet with wood on top and slowly pound in place.
Install back in vehicle.


BMR themselves sells the bushings - their Part # is - bmr nb001. $9.95 each. Unsure what an outside PN or price might be.
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95wagon said:
You want lube lines , then drag a hack saw blade across the hole in about 4 places.
Better yet drill the bolt and the sleeve and put a zerk fitting in . View attachment 206985 View attachment 206986 View attachment 206987
Click to expand...

Love it! Good idea...


The BMR LCAs come with fittings installed, which is super helpful.

www.bmrsuspension.com

Free Shipping on all BMR Suspension packages!

Leader in High Performance Suspension and Chassis Products For American Muscle Vehicles.
www.bmrsuspension.com www.bmrsuspension.com
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1slow96 said:
Likely most (if not all) made by EnergySuspension....
Click to expand...

Most likely? UMI specifically lists Energy Suspension as their provider of poly bushings so it follows that BMR is the same.
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Johnp410 said:
I can speak for bmr, i love mine. Big difference, they are fluted too. Used green grease, as that was recommended by bmr.
View attachment 206999
I got the uppers and lowers, so ive got all poly except for the dog ears. I actually have the dog ears if you want them they were $60 i think. Bmr also sells the bolts needed with nylock nuts for like $35 i think. But im super happy with mine. Great customer service too theyll give you a discount if you call them and order.
Click to expand...

Great thanks. Will get myself a tube of green grease and a gun. Lost mine in the flood.

What discount do they give? I didn't get one.... would've been nice!
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@toonwarrior and others who have installed new aftermarket LCAs:

finally got mine installed after fighting with them and the rear axle.

My problem: where/how did you secure your brake lines since the OEM ones had clips built in and the BMR bars do not?

I currently zip tied a bunch around the LCA on the front side around the rubber portion of the line but the rear part of the line can’t be tied in since it’s near the sway bar and didn’t want the sway bar to act on the line itself.

Hope this makes sense. I can get photos if need be.

will zip ties wear the brake line? Currently using plastic ones but I’ve seen stainless steel ties online as well. They’re not super loose but also not restricting tight.

thank you!!
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