Rear sway bar, what fits?

[AngryMcMuffin]

Hey guys, while I'm waiting on Lunati to send me my cam for my Mercury, I'm thinking of other things I could do while the car is mostly or all the way apart.

This involves adding a read sway bar. What sort of options/amount of work are we looking at if I wanted to add a rear sway to my 87 MGM?

[sick88tbird]

I wouldn’t even consider a civilian “pencil bar”, those are worthless! Lol. A PI bar is a bolt on and makes a huge difference, I’m not experienced with wagon sway bars or their size relative to the PI rear bar. I SUSPECT later model sway bars could be used, but would require some fab work to mount them... that’s something I plan to get into down the road, but I have yet to actually test fit anything.

[Arquemann]

I was actually looking into rear sway bars earlier today. Only thing aftermarket that I'm aware of is the addco 650, which is $200.
Some have mentioned that I'd make a car very prone to oversteer if paired with the stock front bar. I take no sides.

Police bar is thicker than the tow package bar I'm pretty sure. Adding pretty much any bar only requires drilling the original lower control arms or getting original rear sway bar -equipped control arms, which are reinforced. Rest is bolt-on. I'm sure someone here has the details to modifying the regular control arms.

I'd like a rear bar too, but so far shipping has been an issue.

[tbear853]

I was actually looking into rear sway bars earlier today. Only thing aftermarket that I'm aware of is the addco 650, which is $200.
Some have mentioned that I'd make a car very prone to oversteer if paired with the stock front bar. I take no sides.

Police bar is thicker than the tow package bar I'm pretty sure. Adding pretty much any bar only requires drilling the original lower control arms or getting original rear sway bar -equipped control arms, which are reinforced. Rest is bolt-on. I'm sure someone here has the details to modifying the regular control arms.

I'd like a rear bar too, but so far shipping has been an issue.

Unless I were to upgrade the front too, I'd stick with the civilian bar or at most, a PI bar. That Addco is a full inch of solid steel bar, putting it on alone is gonna make for one tail happy rear, especially if a wet roadway is under the tires.

I had a Chevelle and a GTO that had the rear sway bar mounted solely to rear LCAs, but my Addco 650 uses links with poly biscuits to the frame cross member above the muffler rears. The bar itself is attached to the axle housing tubes at two pivot points just outboard of the center diff casting.



Sway bars are about bringing balance, not chaos to the car.

[sly]

Also, with a rear bar that bolts to the control arms, you'll want some spacers that will fit inside the control arms to support the clamping force of the bolt that goes through the entire arm or use short bolts and nuts inside the arm. You can also get aftermarket adjustable arms now from ADTR.net that have provisions for the police bar. The addco bar I think clamps to the control arm instead of bolting to it.

[gadget73]

The small rear bar is better than no rear bar by miles.

wagons had no rear bar, or at most the small one.

Front police bar is 1 1/8 solid, wagon is 1 3/16 hollow. The diameter has more to do with the rate than anything, so you're probably better off with the wagon up front than a police one. Easier to find at least, though at this point none of it is exactly simple.

If we're talking factory stuff, only factory things through the end of the box era just bolt up with zero effort. There are aftermarket rear bars that are bigger but they cost money and I don't know much about them.

Possible gotcha in the back, not all cars had a rear lower control arm with both sets of bolt holes drilled. If you have one hole per side, you're gonna need a hole maker to mount one. Don't recall if the existing hole is the front or rear hole on the bar but its probably on here and you should be able to figure it out. The bar should be in-line with the axle tubes when it is properly positioned. Make sure you put the "dip" in the bar down or it will whack the cover on the diff when the back end of the car is squatted down. It is possible to bolt it in upside-down but it will look funny from the back if you do. If the bar doesn't follow the basic profile of the rear axle, its wrong.

I've run a big rear bar and the stock front. Its not some sort of horribly sketchy handling mess. The wagon bar up front does flatten it out but you aren't going to spin the car out and die with a cop bar in back and the usual 7/8 bar up front.