Here's the scoop. Got the rear suspension and differential done in my 72 Cutlass. Took a long time to get it all new looking but it's worth the wait. Everything went in last night and today EXCEPT the rear sway bar.

I bought the sway bar on line about 3 years ago. It's a 1" bar and was listed to fit 64-72 A body.

Now that I got to install it, problems arise. The distance between the lower rear control arms is 40 1/4 " on the wide side and 38" on the narrow. The sway bar is 41" on the wide and 38" on the narrow.

Is it possible this sway bar was for a 64-67 Cutlass? I think I remember reading somewhere the rear brakes and control arms were wider on those models. Anyone know for sure about this? By the looks of it the sway bar is way too wide to fit my 72

 

Sorry to hear that AL. I can't comment about the situation. But I have a question,,,Where did the bar come from and what "brand" is it? Help keep us from doing the same thing.

 

Mike,
I wish I could tell you. That info was on my old puter which decided to go TU with the information.
LOL: I was describing this to a friend of mine and wrote this to him:

 

hey buddy sorry to hear the situation this might help though. check out malibu or ho performance in california or hellwig. I believe they are in the trade still. I have all of ho or malibu parts on my 71 plus praise dyno brakes at all four corners out of texas. My car handles and stops excellent about a mid to late nineties vette capability all over plus super traction and very cheaply. total cost complete front to rear about maybe 1100 complete with no hop bars included.

 

For some reason I'm thinking I got this sway bar at a Chev site. It was on sale for around 90.00 I think. The Chevelle and Cutlass should be exactly the same for rear sway bars if memory serves.

Wondering if I might be able to have this bar tweaked at a shop so it will fit.

 

Do not quote me on this, but the only sway bar I have heard that would need some tweaking, would be the 1964 Chevelle SS 396. I thought that all other 64-72 A body rear sway bars would fit.......um....

Ted

 

All of the 64-72 A-body cars have the same geometry for the lower control arms,and the sway bars will interchange between all of them.Most of the time,the factory cars came with an assortment of shims behind the factory sway bars,but I have also seen some that did not.Some were a tight fit,and some layed right in there.

 

Allan I required the shims on both sides on mine. You boxed in a set or open lower control arms is it possible the open ones were slightly wider then factory boxed arms? I think there is also the possibility that the lower control arms are left and right if you swapped sides would it give you the clearance? I would think that you should be able to position the sway bar and use a large pry bar to lever it in but you will probably scratch that paint. You also might be able to put the lower arm in a vice , aligned with the mounting holes for the sway bar in the jaws and give the arms a squeeze. Or grind the mating surface on each side of the bar a little on both sides a 1/16th is not much. My assembly manual clearly shows shims required? So perhaps this bar is not quite to factory specs ?
Not much help I know just thinking out loud

 

maybe you could use a ratchet type cargo strap to draw the ends together,it may give enough clearance to install the sway bar.

 

The lower control arms are NOT side-specific.There is no right or left.

 

The reality is that there was NEVER a 1" rear bar offered by the factory for the 64-72 A-body cars (yes, all 64-72 rear bars interchange). You either have an aftermarket bar or one for a different application. It's not surprising that an aftermarket bar would be made incorrectly. Is the problem that you can't bet the bolts in? Can you slot the holes in the bar slightly?

 

Eddie, the only difference between a factory boxed sway bar and the one I did is that the factory one would have been done at the factory 40 years ago. The inserts I welded in should have no effect on mounting the sway bar. In fact the sway bar mounting kit comes with 4 anodized bushings to put between the gap of an open control arm to avoid crushing the sides when tightening the nut down. My decision was to box it in the way it should be. I don't think the CA's are the problem.

I don't think that would work. The outside curve of the bar is a good 5/8" to 3/4" too wide. I would need some serious pulling power to bend the bar that much, and far as I know it would be unhealthy for the suspension to release that much side pressure onto the control arms. These are supposed to fit easily between the rear arms and should need gapping shims.

Agreed. However just for the sake of continuity I did put the CAs back onto the same sides. It was easy to determine which side was which since the e brake cable had worn a small groove in the tops.

Probably is aftermarket - most things are now a days. The problem is nothing to do with the bolts. On one side I can get both in with no problem. Going to the other side, the rear of the sway bar is almost 3/4" too wide to fit between the CAs. My gut says it's the wrong bar. Even if I tried getting the bar bent more in the middle I think that would also affect the front dimensioning more than the back.

 

Brian I will of course defer to you, but i could swear the instructions I got with my repopped boxed arms mentions this, after thinking about it it doesn't make sense sorry for the confusion

 

Eddie, you might be getting the instructions confused with which side is front and which is rear? There's DEFINITELY a front and rear - just check the bolt holes for the sway bar.

 

Is it possible it came from a G body car? I saved one from an 85 Cutlass I used to own and tried to fit it to my car. It fits in the front, but is a little wide in the back. And it's a one inch thick bar.

 

Hi Eddie,
No, the shape and dimensioning of the G body rear sway bar is completely different. Thanks for the thought though.

 

Yes, it DOES have everything to do with the bolts. The arms are angled, not parallel. Sliding the bar rearward puts you in an area where the LCAs are further apart. Slotting the bolt holes lets you put the bolts in. Problem solved.

 

NO, it has NOTHING to do with the bolts. The bolts are just fine and are proper length/grade. Furthermore the bolt hole pattern on the sway bar matches the bolt hole pattern on the sway bar. I know what the sway bar should look like and that the bolt holes should line up without modification. In fact shims should be required to fill in the small gaps between the CAs and sway bar. That's just not the case here. BTW, I know how CAs line up from the frame mount to the rear axle, so I don't need lessons on how they are angled, not parallel. Slotting the bar as you suggested is not going to happen.

 

What we have heaya is a failya to communicate.

Ignore the bolts. The space between the LCAs gets wider as you go further towards the rear. Set the bar between the LCAs where it fits, ignoring the bolt holes. High school geometry says that there will be a point where the bar does fit between the LCAs. When you find that point, how bad is the mismatch between the bolt holes in the LCAs and bolt holes in the bar? If the mismatch is small, you MAY be able to either slightly slot the holes or partly weld and redrill them. Sorry if I implied you needed different bolts. It's the bolt HOLES I'm talking about.

 

I thought of that and did try aligning the bar that way during the attempted install.

 

Lookin like you'll need anotherr sway bar.

 

Here's pics of the bar. As you can see there's no wiggle room that wouldn't compromise structure even if I wanted to move the bolt pattern back. BTW I did put a caliper on this and it is 1"

 

my rear bar came off of my '69 and was put on my '67-no muss, no fuss.


bill

 

That would be an OEM bar though? This one isn't. I think that's why I'm having issues with it.

 

yes, oem bar.


bill

 

Bill
Any chance you have measurements of the bar from side to side where the bolts/nuts line up? I'd appreciate if you could LMK that.

 

Not Bill (!), but I just measured my OEM 7/8" bar :

Ouside surfaces at center of bolt holes
front (of car) holes = 37 15/16"
rear (of car) holes = 40 1/8"

 

Thank you Indy!! That's exactly what I needed to know.
The one I have is rear - 40 9/16", front 38 1/8"

So it appears someone back then shipped me the wrong sway bar. Any idea what kind of car that would fit or if it's even for GM? B Body maybe?

 

Allan, wow, that's quite a difference in dimensions and obviously the wrong sway bar. Good thing you didn't try to modify the mounting holes because if you can figure out what it fits, you can sell it to recover the money you spent on it.

Brian

 

I bought a factory bar at a Chevy site and it was a simple boilt in. I also installed a bar on my 70 Bonneville B body, but the mounting is entirely different, and the big Olds is probably the same. The Bonneville bar mounts on the bottom of the control arms and the A body cars mount on the sides of the control arms.

 

Unless I can get an OEM in decent shape from someone, I'll have to check the aftermarket suppliers. This time I'll ask them for side to side dimensions at the holes prior to committing $$. I have a few feelers out right now.

Brian - Yes, I agree. Modifying the bar was something I thought was a bad idea too. It should fit without having any mods to it. Makes you wonder about some comments at times. Now I just have to find out what car this bar was really designed for and post a FS on the appropriate site.

brown7373 - thank you for the info on the B Body cars. Didn't realize their mounting was so different.

 

Allan,
I have a 1" rear bar from these guys at Muscle Factory on the blue car. It fit perfectly just as the 7/8m factory bar I removed (the one I removed I used on my current ride).
https://classicoldsmobile.com/forums...ars-cheap.html

 

Mike, Thank you for the link and email. I have a feeler out right now to Eric (jensenracing77) and Scott (Oldspackrat) on OEM bars. If they don't have any that are in good shape; not all pitted, that site you linked for me has great pricing. I'll have to see what they say about shipping.

Questions: in your opinion is there much of a difference between the 1" and 7/8" bar as far as handling goes? Did you need shims to install your 1" bar?

 

I used these lower control arms http://www.umiperformance.com/catalo...products_id=34
and yes I needed shims.
I started on the suspension a few winters back, I usually do some improvement each winter. First I put all urethane bushings up front and lower ball joints and idler arm. Next year I sent the steering box and pump to Chip at powersteering.com , had it converted to 12-1. At this time I still had stock rear suspension with factory box arms and 7/8 bar. Next I did front disc and stainless lines with a new complete system and silicon fluid. Next I did the rear suspension with all UMI products, the lowers mentioned, double adjustable upper with roto-joint and urethane bushings, and a pair of frame connectors, and the 1" rear bar and installed a 1.25 front bar I had for years with all urethane front bar bushings. So each thing just made it better and I am very pleased with how it drives and handles now. The best handling "A" body I have ever driven. I know there are many, many better, but still best I have driven. So the way I did things a little at a time I couldn't say the 1" bar alone did or didn't make a difference. But both bars considered together did make a big difference.

 

allan, sorry i didn't get back to you about bar measurements-i've been busy. glad somebody else was able to supply the requested info.

from what i've read over the years, gm liked to have slight understeer in the suspension systems. a larger rear bar with the same front bar may cause oversteer. seeing as how the rear bar mentioned above is 1/8" dia. larger, that's a healthy increase. your front bar is probably 1" dia. something else that may need consideration is the torsional rating between oem bars and aftermarket bars, there may be a difference.

you will probably need shims-you don't want to start pulling control arms inward when you install the rear bar. my cars each required 1 shim on each side, yours may be different, but probably not.


bill