Hey I have a 71 w/ SSM lift bars on the lowers and a set of BMR adjustable uppers. When I put in the uppers I set them at the stock lenght which was as small as they would get. I'm having problems w/ the SSM bars I think. I was at the track on Sunday and after I spun the tires to clean them off when the car sat back down a loud bam from the back. The rear end has been moving around some when I cruise @ 50mph and get on the gas then off I can feel the whole rear move enough that I must correct w/ the wheel. I looked at them and on the lower mount bolt right under the axel tube the welds keep coming loose is this why the rear end keeps moving around?


I have had no problem with them but, I hear some people don't like these SSM bars, I was thinking about getting the BMR lowers to eliminate these complications. Will these keep me from having wheel hop cause I don't have any now but will be upgrading the power plant? I see no reason to have these SSM bars if I have adjustable uppers can't I use these to totaly adjust the rear end?

Thanks Mike

The only thing adjustable uppers do is allow you to change your pinion angle. SSM bars correct the rear suspension geometry, moving the instant center back. This eliminates wheel hop, and gives better sepration and traction on launch.

I don't know what's going on with your rear end, but it looks like you said you're breaking welds on the housing bracket? I wouldn't be driving that car until you figure it out.

Tim.

Do you think the wheel hop would return if I put these lowers on that go with the uppers I already have?
http://bmrfabrication.com/A-Body.htm
Mike

You might not have wheel hop at all. Some folks don't experiance it. Not sure if it can be related to power or traction or what. Are you using the Poly bushings from BMR? That can be enough to stop wheel hop, too (doesn't correct the suspension geometry, though).

The BMR arms are nice pieces and may be fine if you don't already have wheel hop. I'm sold on the SSMs, though.

I have the BMR adjustable uppers and stock length was deffinatly not as short as they'd go. You probably should double check that.

What are you using for lower arms now? What power level are you planning for? Will this be a track car? Will you use sticky tires? It will make a difference in what type of rear suspension you should put together.

Tim.

Thanks for the reply TronDD. I have the SSM lowers with the BMR adjustable uppers and the poly bushings. The lowers are welded properly but some of the welds keep coming loose. The bars are welded on solid but there is a small tab that comes down from the rear bolt and it comes loose there. What kind of adjustability is there to the SSM bars?

The person who had the car before me said it had wheel hop so the SSM lowers were added. Since then I added the BMR uppers and the old upper bushings were shot. I was thinking about the BMR lowers because they have less parts/ stuff to break. Do you think theese would work good?

I was just thinking that if the BMR upper and lower setup would hookup like the BMR upper and SSM lower, I would put on the BMR lowers because of simplicity.

When the car is done it will have a 600hp blown 383. But for now just 350.

Something must be with the lowers

Ok, you're talking some power then. graemlins/thumbsup.gif

SSM bars don't provide any adjustability. They have a lower mounting point than stock which corrects the geometry of the suspension. They only give you one way to install them.

I take it the SSM bar brackets are welded to your housing. I assume the tab you are refering to is the smaller bracket that is located on the differential side of the SSM bar. If they are welded, you'll have to remove them some how to fit stock type bars (BMR).

The BMR lowers might work fine. I can't really say. It's a trial and error, everyone's car reacts differantly, type of thing. Besides using SSM bars to cure wheel hop, you can also try stock type arms and lowering the rear suspension until the arms are parallel with the ground. That has worked for some.

You've got a couple options. It's a matter of what looks easiest to do, I'd say. As I said, I'm a believer in the SSM bars and I'd recomend trying to get those working properly.

If you go that route, I'd ask if you had the bolts for the SSM brackets and if you have a swaybar. I don't think you should be breaking welds. Something isn't right somewhere and I wouldn't blam the SSM bars yet. I wonder if suspension bind caused by the poly bushings is adding stress to that weld.

Tim.

They can't be welded correctly or else the weld wouldn't be breaking. Make sure the SSM Bars are able to pivot properly at the axle when it's all together. Maybe something is binding there.

Peter

The bars were installed before I got the car. I assume the SSM bolts were used. After I got it I spun it out and bent an axel ad snapped one of the forward mounting bolts. I took it too a performance shop around here and they said I should weld the bars on instead of just the bolts. I said ok so they welded them. They replaced my axel and the bolt.

Yes, the part that keeps coming loose is the small tab on the differential side. Are yours welded there? Do you have any pics of what it should look like? If that piece is loose could this be where the play is coming from? If there is no adjustability should I have that piece tig welded on?

I had a guy tack the small tabs down and his welds look like boogers. This was a different person than the ones who welded the bars on, they did a good job.

No I don't have a rear sway bar. Do you think this would help stiffen everything up? What brand should I run if so? How about BMR, they are in FL and have good prices for high quality, beefy parts that's why I like them.

One last thing, what about these support bars I see from Hotchkis for the front mounting point is anyone running these?

Thanks a lot,
Mike

TronDD, looks like your rear setup is similar to mine. What bushings do you have in your uppers?

Originally posted by stealth71:
Yes, the part that keeps coming loose is the small tab on the differential side. Are yours welded there? Do you have any pics of what it should look like? If that piece is loose could this be where the play is coming from? If there is no adjustability should I have that piece tig welded on?Mine are not wolded at all. Just bolted to the rear end housing. If that piece is not secured to the housing, it'll definatly couse prablems. The arm will only be bolted to the housing on one side, that way. Not safe at all.

Originally posted by stealth71:
One last thing, what about these support bars I see from Hotchkis for the front mounting point is anyone running these?I have a set from Edelbrock. Not installed yet. They won't fix any problem you're currently having but might be nice to have for the future power you'll be running.

In the upper control arms I have the BMR poly bushings on the frame end. and Wolfe Racecraft spherical bushings on the housing end. I went with the spherical bushings to help eliminate the suspension bind that can be caused by poly bushings.

Any sway bar should work fine but there are spacers that go into the SSM bar when you use a sway bar. I'm guessing you won't have those. I asked about a sway bar because it will transmit some of the suspension travel to the other side of the car maybe reduce some of the forces you are seeing that are breaking things.

Like Peter said, you should check to make sure everything articulates correctly.

Tim.

Thanks for the help. The spherical bushings look nice are they worth $120. Maybe I need the different bushings. I have all poly uppers. How can I tell if there is bind? How about the adjustable lowers, could the instant center be adjusted with those?

Instead of the spherical bushings, you can use rubber. You probably won't see much deflection whith the rubber if you have poly in the other locations. You will prevent suspension bind, though. The spherical bushings stop both the deflection and bind. Unless you're going to be at at the track a lot, I wouldn't spend the money.

You can check for bind by putting the back of the car in the air and lift one side of the rear end. One side should move through it's range of motion without the other side moving much. If you lift one side and the other side lifts up too, it's binding.

No, adjustable lowers don't change the instant center. Instant center is determined by the angle of the control arms. If you look at the rear suspension from the side, extend the length of the upper and lower control arms forward. Where they cross is the instant center.

There is a diagram here: http://www.metco-inc.com/controlarms/instantc.shtml

Tim.

Alright I've been thinking about this for a while now. First I think I need to check my pinion angle. I never checked it after installing the BMR uppers, I just set them to the same length as the original. I think suspension bind might be possible with all poly upper bushings I have. Would this break those small welds?

What kind of bushings, if any, are there on the SSM bars?

I think the spherical bushings you have would be nice. If I weld the small tabs again and install the spherical bushings, Do you think this would fix it?

How hard were the bushings to install? The original ones I took out were a PITA. Do the sphericals install easily?

Thank you very much.
Mike

Forgot to mention I have air bags in the springs.

I think suspension bind might be a factor. Poor welds are just poor welds, too, though.

SSM bars have something weird for bushings. I forget what they are exactly. They may even be solid, I forget.

The spherical bushings are pretty easy to install. They are big bolts so they are "screw on". You don't have to press them in. Push them through and put a big nut on them with some loc-tite. I had to do some grinding to fit the driver's side on a 12 bolt housing. Just groud away some of the nut to fit the curvature of the housing. Also, BMR uses a wider bushing than stock so you need some spacers betwen the spherical bushing and the control arm. I just used washers.

I think you're biggest problem is getting the SSM bar's brackets welded properly. That might solve everything major. Changing bushings will be nice to eliminate binding but I don't think that's the major problem, even if it's contributing. Some guys run poly all the way around and they don't break things.

Tim.

You say the bars are welded on and those extension tabs are welded to the housing? That makes no sense at all. There are tabs that are attached to the housing to provide a new mounting hole location below the origional one. Then, the SSM bars bolt through the new hole location. The bars should be free to pivot at both ends. I believe one end is a spherical joint one one end and a poly bushing on the other.

If your performance guy recommended you weld the bars solid at one end then I suggest you NEVER go back there again. That advice has cost you a set of lower control arms.

Peter

SSM bars are not spherical on either end. I don't remember seeing any actual bushing material like when you look at a rubber or poly bushing (you see a lot of material on those). You just put the bolt through a metal sleeve.

I think he's saying the SSM bar mounting brakets are welded to the stock mounting brackets instead of being bolted on. That's what I've been thinking.

Tim.

Originally posted by TronDD:
SSM bars are not spherical on either end. I don't remember seeing any actual bushing material like when you look at a rubber or poly bushing (you see a lot of material on those). You just put the bolt through a metal sleeve.

Tim. I'm just confused then. Maybe it's the Global West then that are a bushing and a rod end? Maybe I'm just confused because I'm going to try making some that are a poly and a rod end.

At any rate;

Originally posted by stealth71:
I had a guy tack the small tabs down and his welds look like boogers. This was a different person than the ones who welded the bars on, they did a good job.

Thanks a lot,
Mike This sounds to me like the bars are welded to the tabs and the tabs are then welded to the housing. Not good. There's no pivot point and the suspension can't work.

Peter

Yeah, I think Global West has an arm with spherical on the frame end. I know that Edelbrock definatly does. I though both were upper arms.

I read that to mean the first guy who welded the mounting brackets on verses the guy the rewelded it after they broke once. I guess we wait and see what Mike says... Having no suspension travel would be a rough ride. smile.gif

Tim.

Sorry I didn't get back sooner. The brackets are welded to the rear and the small lower inner tab has a small weld that breaks. The bars are free to pivot at both ends. The guy said the the mounting brackets should be welded instead of just bolted. I took a couple pictures but I have a snail camera not digital. I'll develop them today. Scan and post I think this will clear it all up.

The guy said the the mounting brackets should be welded instead of just bolted not trying to dispute the guys claim, but dont you think if the brackets needed to be welded to the rear end ssm would have made them that way?

i and countless others here are using the ssm bars and they work just fine bolted to the rear end.

I know what you're saying. I think he probably just thought it would be stronger.

I've had mine on for over 3 years,and they don't even come loose. I check the torque a couple times of year and they are still tight. It sounds to me like someone didnt quite know what they were doing when they were originally installed. :confused:

Stealth,I sent you some pics of mine installed.

And that "tab" is as much a bracket as the plate on the other side and needs to be fully welded, or bolted on, too.

Tim.

Today I took the grinder to the old welds on the tabs there was some rust under them probably why they broke. Went and got it welded and everything seems fine. I get some pics up soon.