'70 rear sway bar

Is the Cougars rear sway bar straight across the back or does it have bends at the attaching bushings/brackets?? Cougar is 1/2" and Mustang was 5/8". I thought I remember the bar being straight but remembering from 2005 was some time ago…

Never seen a straight rear one either aftermarket or original.

Rear sway bar

Here’s my experience with the rear sway bar. The write-up is from four years ago somethings may have changed.
Rear Sway Bar for a 1970 Cougar.
I’ve had a series of issues in adding a rear sway bar to my 1970 Cougar. Several manufactures of after-marked bars have been bought, installed, removed, and returned. The initial install was done in conjunction with rebuilding the front and rear suspension. A chronology of the different ones tried and the issues found with each are listed below. After attempts to use different end link lengths and considering moving frame rail attachment locations with the third bar, I drew a scale drawing of the frame rail, and axle/spring assembly including movement up to the frame stop/bumper.
The Cougar rear is different from the Mustang. The leaf spring is longer and presumably has more height and vertical travel. The longer springs and wheel base may change the relative position of the axle to the frame rail compared to the Mustang. Factory rear sway bars use longer (added~2”) end links than the Mustang. These differences may be part of the problem in finding a workable product for the Cougar. Generally, all of the aftermarket bars struck either the axle to spring U bolt and/or the axle bump stop mount. The ’69 and ’70 Cougars while very similar may not be the same in this area. The WCCC site shows that the have common mounting plates. The OEM ’70 will not fit Mustangs. Some additional thoughts on the ’70 factory bar and its mounting are included below.
I did not pursue using a factory sway bar since they seem expensive and hard to find. I have not seen any information on how or where they attach to the bar body but have surmised a good bit about them based on the WCCC site information.

  1. ADDCO #995 (Scott Drake C7ZZ-5486) - This is a 3/4” bar that attaches to the frame rail behind the axle and with end links to the leaf spring immediately in front of the axle. I found holes already available in the frame rails in a usable location and used them. There were issues with this sway bar.
    a) With this installation location on the frame rail it runs right through the factory dual tail pipes.
    b) Missing hardware
    c) The sway bar hits the top of the leaf spring U bolts when the axle is bounced up.
    d) Attempts to contact ADDCO for tech support got no response by either email or phone. I did not attempt to contact Scott Drake for tech support.
    NOTE: See 4) below for a second more successful attempt using this bar with modifications
  2. Hellwig #6806 – This is a ¾” bar that attaches to the axle and the end links attach to the sub-frame in front of the axle. This bar went in nicely with some adjustment to the rear brake line to clear. However in trying to install the end link mount (drilling the sub-frame) it became apparent that the end links needed to go through the parking brake cables on both sides. Some discussions (with pictures sent) with Hellwig came to the conclusion that theirs would not work. These may work on earlier model Cougars that appear to have different routing on the parking brake cable. Pit Stop USA took the return and provided a refund including return shipping once they confirmed the issue with Hellwig. By the way, Pit Stop provided good service on the phone, a good price, prompt shipping, and easy return. They were relying on Hellwig for fit information.
  3. Eibach #3561.312 – This 7/8” bar attaches to the frame rail forward of the axle (new holes drilled to mount it) and with end links to the leaf spring immediately in behind of the axle. This bar went in nicely (did have to disconnect both shocks at the bottom and drop the mufflers and tail pipes several inches to thread it in), it has stout hardware. However, it like the ADDCO bar hits the top of the leaf spring U bolts when the axle is bounced up. Attempting longer end link lengths moved the bump point to the end link hitting the axle bumper/stop mounting bracket. Contact with their tech support for return, provided pictures of the issue and got a return authorization. They didn’t volunteer to cover the return freight nor did I press the issue (a $70 error on my part).

At this point I made a scale drawing of the sub-frame, and axle/spring assembly including movement up to the frame and axle bump stop.

  1. Round two with the ADDCO bar above – with the scale drawing of the car, I reviewed the ADDCO bar installation. The sub-frame attachment can be moved back up to 2” to clear the tail pipes. There are some reinforced (a ¼” reinforcing plate inside the frame rail) areas further back that could be stronger, however only one end of the bracket would be in the thicker area. If the end link length is increased to use a 7-1/2” to 8” grade 5 bolt with about a 2¼ to 2¾” spacer (originally a ~5-½“ Bolt and 5/8” spacer) the bar no longer hits the spring U bolt. The spacers can be easily made from ¼ NPS pipe. The longer link must just clear the axle bumper/stop mounting bracket at the top of its movement. Check the fuel line for clearance on the driver’s side. This arrangement works with the bar limited in movement just barely between the axle U bolt and the axle bumper/stop mounting bracket. This modified fit to clear the factory tailpipes is untested at this point since my pipes had previously been rerouted to clear.

In reviewing the WCCC site and other data I’ve surmised the following for ‘70’s factory sway bar. This is a DOWY-5A772-A and the related pieces. It is shown on the WCCC site but is out of stock. It is lighter, only a ½” diameter, it is slightly wider (to clear to the outside of both the U bolts and the axle bump stop mount), it has longer arms, its end links attach to an added plate (also special) under the spring just forward of the axle mount and to the outside of the leaf spring, and it attaches to the frame rail behind the axle (probably using tapped holes in a reinforcing plate inside the frame rail). ADDCO indicates that they make a replacement bar #432 but it has no mounting hardware.
There are other aftermarket bars available but the all appear similar to those listed above.

That bar you posted from Wccc is straight across the back then makes a 90 degree turn toward the link.

The bar I’ve posted has a bend up and down where the brackets attach.

If you can find all of the attachment hardware this is probably a good way to go. It might be a bit pricey.

70XR7Tom. I have the attachment hardware. I use to have a B2 Cougar. I bought nos end links from John’s years ago and have the used brackets/ bushings. Bushing look Great. Did you look at the link Royce posted? That bar looks straight across the back.

The picture you posted is the 1971-73 Cougar rear sway bar. The link I posted was to the 1970 rear sway bar. There is a big difference. There was no factory rear sway bar in 1969 for Cougars.

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Use Royce’s WCCC link for the sway bar picture and details on the correct hardware. As was previously stated the 1970 stuff is unique to '70. Back when I was looking I did find a few originals without the hardware. There may be some out there now.

1970 Mustang OEM 1/2" Rear Sway Bar & NOS D0ZZ-5A486-A Stabilizer Bar Link Kits - The Marketplace / Miscellaneous Parts for Sale - Classic Cougar Community Forum

Here is what a 70 rear sway bar looks like. I bought one from gary miller years ago with just the bar only. I had to buy the plates separate, also had to make my rear end links from longer bolts and bushings. The sleeves where the bolts go thru i made from steel tubing proper length.


My research showed that the Mustang bars don’t fit the Cougar.

They don’t.

Ok that explains that. But while digging looking for Eliminator undercarriage images, I found this Eliminator and it had that '71 bar on it. Adding to my confusion.

Pat that looks like a Mustang bar and is titled a Mustang bar. You can barely see the bends where the bracket go.

This is what I have, I purchased the straight bar under the assumption it is the correct rear bar for my eliminator. I didn’t receive any of the hardware that went with it (pictured at bottom). The other bar is a mustang 1/2 inch. I also have another NOS rear bar (not pictured) with a D0ZZ… number on it, it is a larger diameter than either the mustang bar or the cougar bar pictured. It has the same bends in it as the mustang one pictured, but I don’t know what it is for?

This next picture is what I believe was for the cougar bar, it has been a long time since I purchased it. The bolts and the spacers are longer. They are not reproduced as I am aware, and dead nuts recommends getting the Mustang ones and welding them up to make them longer.

The spring plates (that go under the main rear springs) are different than mustang too, something about both sides being the same. I recall reading about it on the WCCC site?

Peter :slight_smile:

How are things down under? Can you take a picture of the Mustang bar on top of the Cougar bar to check dimensions and place a measuring tape to measure each? They look to be the same except for the bends on the back of the bar. Maybe the bends were put there to help clear the exhaust?? Is your larger bar 5/8 vs 1/2? Thank you for your help to clear up some issues about these two bars.

You can also buy grade 8 bolts at the right length. The extra threads you won’t see with the sleeve and the bushings/washers. Pat said above you can buy the steel tubing and cut to length.

Here are the measurements of a 70 rear sway bar plus the 12 inch bolt.

Thanks. Now I just need to find a Cougar bar!