Thread: Addco 639 Rear Sway Bar

Originally Posted by GTPNovak

Update: Summit dropped the ball on me after waiting since 10/11/16. They said they placed my order but some how wiped out my entire account. CS was very helpful and did everything they could to make it right, but they claimed Addco no longer makes the sway bar (not sure if this is true or not). They offered me a big discount on a different bar they had in stock but was the 19mm AcDelco bar. I had already bought the ES poly mounts. So i went looking to other suppliers. Jegs was the winner they not only had it in stock for shipping the same day but also met the price of never enough auto.
Not sure if Addco really has stopped production but if anyone wants a Addco you may want to hit up Jegs as they are in stock and dont have to wait a month for it to be made like i did with Summit.

Personally i am unsure if i will do business with summit again because they wiped out my entire account and never once notified me. I have done a lot of business with them in the past years and have always been very happy. Jegs for the win!

Glad you were able to find one. I bought my BMR trailing arms from Summit at $89... prices have inched up though as I am planning on a pair for my Impala LTZ.

Now for a word on Addco... In a nutshell, there customer service blows donkey balls... in fact, it is non existent. The bushings that come with the sway bar, in my opinion, are garbage. They made noise on my Grand Prix from day 1 and it took me a little while to figure it out. How did I figure it out? I brought the Impala home from the dealership and swapped the Addco bar out of the GP into the Impala before I turned the GP in on trade in (yes, the dealer knew I was doing this). On the test drive on both cars, the GP first, I noticed the rear of the car was quieter. Took the Impala out... Mother F'er... the bushings were making the same noise as in the GP. I have called Jegs... they can't communicate with Addco any better than I can pick up the phone and try. I have emailed Addco twice... No response either time. Sorry, their sway bar might be good, but the bushings blow and so do they for their crap service. .


I have searched on here and saw where guys have used Energy Suspension bushings in place of the factory bushings and/or other supplied bushings with other swaybars. I don't quite understand how the ES bushings work since the GP bushings are keyed to the subframe. Also, for the Addco, the bushing needs to be 22mm inner diameter for a reasonable fit. If anyone that has used ES bushings can chime in with more detail, I would like to know how to make them work. I may buy a pair of Moog blue thermoplastic bushings for stock GPs and a set for another GM vehicle and see what I can get to work.

Originally Posted by WickedGoat

I have searched on here and saw where guys have used Energy Suspension bushings in place of the factory bushings and/or other supplied bushings with other swaybars. I don't quite understand how the ES bushings work since the GP bushings are keyed to the subframe. Also, for the Addco, the bushing needs to be 22mm inner diameter for a reasonable fit. If anyone that has used ES bushings can chime in with more detail, I would like to know how to make them work. I may buy a pair of Moog blue thermoplastic bushings for stock GPs and a set for another GM vehicle and see what I can get to work.

So I realize this is over a month since your post but I'll reply anyway in case you still need help or someone in the future does. What I did was take out the bracket from the original bushings and replace it with the one that comes with the ES bushings. All you need to do it widen the hole with a dremel to get the new one to fit. Slide it in and then bolt the other side down. Tight fit and won't go anywhere.

Originally Posted by SomeDudeAtHome

So I realize this is over a month since your post but I'll reply anyway in case you still need help or someone in the future does. What I did was take out the bracket from the original bushings and replace it with the one that comes with the ES bushings. All you need to do it widen the hole with a dremel to get the new one to fit. Slide it in and then bolt the other side down. Tight fit and won't go anywhere.

When you say widen the hole, are you referring to the slot on the subframe where the top of the bracket would slide in? Just making sure I understand.

Originally Posted by WickedGoat

When you say widen the hole, are you referring to the slot on the subframe where the top of the bracket would slide in? Just making sure I understand.

Yes exactly

Originally Posted by GTPNovak

Thats how i understood it.

So my plan was to take the 9.5126G (G just means that the bushing is graphite impregnated) remove the bushing and put into the stock metal brackets. Maybe i will look into what would be needed to modify the bracket or body to get the ES ones to fit.

A larger bushing will not fit into the stock bracket. You'll have to widen the hole and slide the ES bracket in. It's really easy to do. Worst part will be running the extension cord.

I pulled the Addco bushings out today and just greased them, even though Addco says you do not have to. The bushings are silent now. Should have just done this from day 1 but whatever... I am assuming the Addco bushings are poly so to me there isn't much reason to buy ES and modify the bracket to make it work. My Impala is totally quiet now.

It's been several years since I installed mine but I'm 99% sure that the ones that came with it were just rubber and not poly.

Straight from Addco's website...

7. Do I need to lubricate my bushings?

No, ADDCO is pleased to offer an industry-first maintenance-free urethane midsection bushing with our anti-sway bar kits. In conjunction with a key trading partner, we developed a new urethane bushing that has a self-lubricating function that cannot be made to squeak under more extreme conditions than what vehicles are normally subjected to. There are a couple of exceptions.

So they are urethane, better than rubber, not as solid as poly. Urethane has always been touted as never making noise, thus a good alternative to polyurethane if you didn't want noise or the additional maintenance of greasing the bushings to keep them quiet. My Addco bushings never squeaked, just made the infamous mattress bounce noise. They did this from day 1 when I installed it in my Grand Prix and continued to do so in the Impala. Overall I am still annoyed at Addco but at least the dam bushings are silent now. Took my kid to school this morning and hit every bumpy road I could find, not a peep from the car. I am fine with urethane. If energy suspension will make a bracket and bushing set specific to our W bodies, I may buy it.

Thanks good to know. Seems like they've updated them since I bought my bar.

All urethane bushings I've used (ES included) squeak like hell unless they're lubricated, I find it funny ES plays it off like you don't need lube.

I like to wrap some teflon tape around the bar where the bushing sits and then grease the bushing. It seems like where I live the grease alone barely lasts a year until the squeaks come back.