Write-Up: ES Bracket Wear - UMI Performance Brackets (for Addco sway bars)

Write-up is below: https://rivperformance.editboard.com/t9833-energy-suspension-sway-bar-bracket-wear-umi-performance-solution#158843

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I was in the area and saw this which at first glance, I figure was just because one side of the car was lifted but then I noticed that it looks like the bushing clamp is being pulled upward as in bending. Who knows how long it's been like. Anyone else see something like that with their addco & poly bushings?

Mine were locked down tight and never did that, but instead tore the subframe free around the retaining nuts!!! My brother doesn't corner like I do, so he opted for complete removal of the sway bar and with just the STB it actually still corners surprisingly well.

I may have an extra set, will try to check the garage today.

I managed to stretch out (compress) my ES poly bushings over a 2-year period, but didn't notice the metal bracket was bent like yours. I have also not seen any stripping of fasteners as deekster has. Solution for me was a new set of bushings, which come with new brackets. Easy fix for $25 or so.

Half of me wants to believe our front sway bar actually has the means to apply immense forces to the brackets, causing the type of wear seen here. The other half has witnessed my own car go through daily driven abuse, pushing the car into .8-.9 lat G territory more often than GM or even Addco probably intended. A dozen or so autocross runs and more than a hundred hot laps on the road course - I have encountered only some understandable compression of the poly bushing, resulting in a loose-fitting bar. The hardware was fine.

Still, it is intriguing, and I hope to know what ultimately caused these episodes to your and deekster's cars. I wonder if after the poly compresses so much, the added movement inside the bracket is enough to build inertia, causing a "hammer effect", doing even more damage to the bracket or mounting screws? Since I caught mine and replaced them, maybe they didn't have a chance to get quite as bad as yours?

One more question: was your car ever supported on one side (suspension compressed) for a long period of time? If the bar were in torsion for long enough, I could see this happening. It would not explain deekster's stripped screws, though.

Just to clarify - my car did not strip the screws/bolts, but tore the metal right out of the subframe!

I'm guessing our uneven/potholey new england roads are more to blame than my pushing it through the occasional offramp.

deekster_caddy wrote:

Mine were locked down tight and never did that, but instead tore the subframe free around the retaining nuts!!! My brother doesn't corner like I do, so he opted for complete removal of the sway bar and with just the STB it actually still corners surprisingly well.

I may have an extra set, will try to check the garage today.

tore free at the subframe = metal fatigue/maybe corrosion/design issue as implemented (the upgraded sway bar passes energy instead of absorbing it

I've noticed a rattle in the front end for the past few thousand miles, more pronounced when braking or going around turns, and getting louder. I checked the ES sway bar bracket last week and surprise... it looked just like Codith's. Bracket is bent and the bar was slopping around in the bushing quite a bit. Inspected the bracket - seems like this could be caused by 3 things:

1) the ES bracket is a universal design. The slots for screws are pretty long, and our screws mount outside toward the ends, so there are weak areas between the screws and the bushing portion where the bracket will bend (with enough upward force).

2) using a stout set of end links and hard urethane link bushings means more load is transferred to the bar bushing and mounting brackets. This creates a new weak point in the design: the bracket. You and I both are using beefy custom end links with hard urethane bushings, so this makes sense.

3) the Addco bar is much thicker than stock, and is solid, not hollow. This means more torsion load can be applied to the bushings and brackets in hard cornering. I think with a stock bar there is a chance the bar would fail before bending the brackets. I've heard of this happening with some other Buicks.

I started to think about how to reinforce the brackets so they would not bend. Though about thicker washers under the mounting screws to spread out the clamping force, or welding additional steel plate to the flanges, adding gussets[/u] between the flange and the clamp, even created a 3D CAD model to CNC from billet aluminum (quote came back for $200).

Then I found these:





Part# 0047 - $89 + shipping from UMI Performance out of central PA. A little pricey compared to ES brackets, but they do come with bushings (appear to be identical to ES), and they're even clear anodize coated. It took me about 5 secs to make up my mind to buy these, and now looking at the parts recieved, I couldn't have fabricated them for anything close to the same price.

UMI is one of those rare, small-town companies who manufactures 99.9% of their products in-house from start to finish. You can pick up the phone and talk with someone, compare measurements to know they'll work on the Riv, etc.. Very quick with email, too. Only thing: my order was delayed about 3 days because they needed to anodize the parts, and shipping was USPS, took about a week (they let me know this when I checked out). Still, well worth it, glad I can support UMI. Can't wait to slap these on.

Those look very nice! Hopefully this won't just mean the forces will take out the cradle instead of the brackets like Derek lol. Hmm I could totally make those but it would take a little bit and I cannot anodize 'em. Wanna take lots of measurements off them anyways?

I have to get after this problem still, myself but one thing at a time.

turtleman wrote:

Those look very nice! Hopefully this won't just mean the forces will take out the cradle instead of the brackets like Derek lol. Hmm I could totally make those but it would take a little bit and I cannot anodize 'em. Wanna take lots of measurements off them anyways?

I have to get after this problem still, myself but one thing at a time.

The cradle attachment points have to be reinforced to distribute the stresses. Our cradles are hydroformed and my guess is they get thin where the metal is shaped fore and aft of the SB bracket attachment points. Age and fatigue don't help. Reminds me of the fatigue problems in the DeHavilland Comet (first passenger commercial jetliner) airframe. (interesting story, do a Google search if you want more)

if you can get the cradle thing clean enough then you should be able to epoxy the reinforcements on.

There is the possibility either the screws could snap, or the threads could strip out/tear from the cradle. If this should happen, using stronger fasteners, and/or drilling through the cradle and capturing with a nut should do the trick. The cradle itself is plenty strong to support this type of load. If it's rusted that badly to cause concern, there's more to be worried about than the sway bar mounts!

(see above post for info on ordering UMI Performance brackets)

They fit! Easy to install, too. 80% of the work is removing the 4 bracket screws. There's only 15-20º of ratchet angle, so it's click, turn, click, turn, click... An air ratchet should cut the time considerably.

Here are the old brackets, both sides bent. There was approx .150" slop for the bar to move up/down.

Right side:





Left side:





I used larger 7/16" grade 8 washers, found at AutoZone for $3. These fit the new brackets perfectly.



Installation is simple. Insert the steel plate (comes with Addco front bar; if you don't have the Addco bar set, you don't need this mod), then position the bracket as shown and push down into position.







You may be wondering if there any clearance issues with the tie rod boot at full lock. Well it's close (about 1/8"), but the boots just miss the grease fittings at full lock, both sides. Ride is nice and tight again. Thanks UMI Performance!

Those look very nice!

deekster_caddy wrote:

Those look very nice!

Yes, yes they do. Me likey...

So, going on four months, how are these holding up?

Any issues with the bolts or subframe stripping out?

I wonder if one would have acceptable results by adding some large "fender" washers under the bolt to reinforce the ES bracket? Would be a lot less expensive option.

Al

They feel like they're still new. I think the subframe bolts issue is aggravated by the bending of the brackets. After it gets loose, the bar can move around in there and could strip out the bolts or cradle. That's my theory, anyway.

I thought about using washers, or welding a washer to the bracket. It certainly would help things. They need to be very strong, something like these in 7/16" or 1/2" size:

http://www.mcmaster.com/#standard-flat-washers/=o6i50z

I just ordered the UMI brackets. They're $99 now. I could have made them but this is not something I want to be going back and fourth trying to perfect on. I want installed and done!

Yeah, I went through the trouble of modeling the file in 3D and sending it out for quote. Even without the grease fittings and poly bushings, the price to CNC machine these would be over $100. And then they clear anodize... Even for $99 you can't beat the quality you get, and it's made in USA!

Hope you mentioned rivperformance.com!

Yup I did

Was there ever an upgrade for the rear sway bar brackets?