[toploader]

Hello all- I am new to the group, and just like all of you, I love my cat. I have a question, but first let me give you a little background to what led up to the problem. I have a '67 standard that I am about 80% done with the ground-up restoration. I am going the restomod approach, with a high revving small block 4-speed, and 4:11s out back. I had the leaf springs off the car for about a year and a half, and never took the packs apart. When I reinstalled them in my car, I eliminated the rubber sandwich mount, and used stang shock plates instead. I replaced the shackles with stock style aftermarkets. Heres the problem: My car sits very high in the rear, as if the springs re-arched themselves while they were off the car. I had to load up the trunk with about 15 8" concrete blocks to get it to squat down enough to bolt up the kyb shocks! When looking uder the car, the shackels point straight up and down perpendicular to the floor, instead of towards the rear. The engine and trans is in the car, but no doors, decklid, interior, or rear bumper. I weigh 230lbs, and if I stand in the trunk, it only squats down a little bit. The rear suspension is very stiff. I can't believe that adding the interior and sheetmetal that I mentioned will make that much of a difference. Heres the kicker- before I tore it all down, the rear end actually sat a little lower that the front, and had air shocks to level everything out, and give it a slight rake. Has anybody else experienced this? Whats going on here? Sorry this is so long, but I wanted to be very specific. Thanks to all.

 

[modifiedmark]

Well eliminating the rubber in the mounts will mount the rear closer to the springs and increase the ride height some. But I'm guessing that you installed and tightened the shackles with the rear end hanging and new the rubber bushings are tight and thats whats actually giving your springs a new arch.

You should have lowered the car down on jack stands under the rear end before tightening the shackles and the front eye bolt. So if I'm correct that you did it this way, go ahead and loosen all the bolts up with the rear hanging and then lower the rear on jack stands and retighten them and see if that makes a difference.

Oh, and welcome to the board. mm

 

[toploader]

Thanks for the reply Mark- I forgot to mention that the front spring bushings are the originals, and I tried to use the old bushings in the shakles just to see if this was the problem, and it does the same thing either way. Right now everything is very loose, and has been for over a year. If I put my floor jack directly under either one of the springs and raise the car, it will compress the way it should, but if I put the jack under the center section and raise the car, it only compresses slightly.

 

[modifiedmark]

Well, I tried then! My guess is that when the car is finally back together and the tank is full of gas then a short drive will put everything back to normal after it rubs the rust out of between the spring leaves.

You are still going to gain some ride height with the Mustang spring plates which is probably a good thing.

Dark 7068 was working in a spring shop and might have some more to add to this. mm

 

[Cougrrcj]

Rear spring arch

I have eliminated the Cougar 'rubber sandwich' spring mounts on AlphaCat as well. I'm not sure about your earlier years, but my 71-73s use a cast iron wedge plate to get the pinion angle right to compensate for the longer leaf spring. I had to do a little modification to them but got them intalled with the Mustang-style solid axle mounting plate. Don't forget the wedge plate!

I'm running a set of homemade plates out of 3/8" steel plate that my buddy Terry whipped up that will allow direct mounting (welding to) a set of homemade traction bars. None of the usual aftermarket traction bars are long enough to reach the front spring eye like they should, so we're making our own! As soon as we get the car back down on its feet and all back together to be the angle right we'll weld on the 'bar' part to the plate.

 

[modifiedmark]

CJ, off the top of your head how much stock downard angle is there supposed to be? mm

 

[toploader]

I eliminated the shims with my setup--I'll have to see how things work out when I get it on the road. The driveshaft angle "looks" acceptable, but only driving it will tell the tale.

 

[Cougrrcj]

Wedge plate angle

Oh, sure, now you ask me! Now that the rear end is bolted in the car. Hmmm, the plate is about 6" long, and the thickness is about 1/8" at the front and 3/8" at the back. Now I'm sure one of you mathmatical geniuses can figure out the angle. Let me take a stab at it...

in 6" there is a 1/4" angle increase, so that makes it close enough to .250 for 6", or close enough to .040 for 1". Take the proper arctangent to get angle....(plugging into calculator and....) we get 2.5 degrees.

I suppose now you're gonna make me go out and unbolt one to check my measurements, aren't ya?

 

[Cougrrcj]

OK,

Just to settle this once and for all, I went out and unbolted the rear end u-bolts and removed one of the wedge plates. (the things I'll do to prove a point, eh?)

OK, so I was a little off in my guesstimates. The plates are 5" long, not 6", and the taper is from 1/4" to 1/2", or still 1/4" total 'wedge'.

Now that makes it .050 per inch of length. The arctangent of .050 is ....(calculator time again)... 2.86 degrees.

Almost three degrees. I'd say that is a significant enough ammount to worry about. Let's put it this way, if the Ford engineers thought it was worth making special plates for Cougars (over the Mustang) at a couple of bucks per car, it must have been necessary, eh?

This is the wedge angle for my 3rd gen Cougars (71-73) and may not be correct for your earlier cars, but I'm guessing it is close enough.

Are we happy now? :

 

[72cat]

Hi Toploader, welcome to the forum.

 

[dark7068]

early cougar's dont use the wedge, and are only neccecelary if the pinion angle is out. When bolting up the shackles, all the weight of the car should be on the wheels, doesnt matter about the front eye bolt, cuz it goes in a metal tube, and is made to move. I dont now why they lifted up when they where stored, could be mini-gremlins bending them while they were in storage so you'd have a bad-ass looking car. The stock style aftermarket shackles are probably longer then stock, 1/2in. difference in bolt holes will raise the springs up alot, which sounds like the problem.
If your still confused, I'll ask my friend and see what he says. Email me your questions and I'll send it off to him for an answer.

Rick

 

[modifiedmark]

Geesh, your the man CJ! I was just having old mans memeory fade and was thinking that 3 deg was right but I get confused after all those circle track cars and there settings. They were set at like 5-9 deg but that was because the rear suspensions had pull bars or 5th coils to let the rear wrap up to soften the instant power to the rear wheels and also transfer weight to the rear wheels by actually lifting up on the rear of the chassis and pushing down on the rear end for traction.

But I was just checking for the future rear suspension mods to the next car. Just in case I actually find one!LOL mm

 

[Cougrrcj]

Wedge plates

Rick,

Every 71-73 Cougar I've ever had (and that's a bunch, 8 at last count) have had the wedge plates. Toploader's 67 had the wedge plates... I'm guessing that all Cougars had wedge plates (along with those stupid rubber sandwich mounts). The reason I say that is Cougars and Mustangs were coming down the same assembly line. Ford tried to keep the majority of the car the same (under the skin) so as to maximize parts commonality if they could. It just makes sense that all of the rear axles assemblies would be the same for the Cougars as for the Mustangs. I mean, how could you tell them apart, really, if the axle mounts are off by just 3 degrees? Hmmmm. Cougars get the rubber sandwich. OK, That's easy to see. Then if Cougars get the sandwich, they also get the wedge plate. Simple enough that even an assembly line worker could figure that one out.

Oh, why the 3 degree difference between Mustangs and Cougars? Well, the cars are the same under the skin from the front of the car to the front leaf spring eye. Cougars have a longer wheelbase. Cougars have longer rear springs. If the axle is moved back along the arc of the leaf spring, the pinion angle is going to change, hence the need for a 'correction factor' wedge plate!

My buddy's 70 Torino is the same way. They also have looooong leaf springs. They also have the wedge plates!

OK everyone. Here's an assignment for y'all. If you suspect that your Cat's rear springs are original or unmodified, go out and look at your Cat and see if it has the rubber isolators and wedge plates. Let us know what you find.

 

[swamper]

Just crawled under car 69 Emiminator no wedges.

 

[dark7068]

All of my old Fords had a 1/2in. plate (flat, no wedge) that rest on the rear perch, then the axle on top of that (as a guide). I Must be missing something.

rick

 

[greggieatthebat]

Can someone post a pic of this mystical magical wedge that we're looking for? (or what it would look like if it weren't there?)

 

[toploader]

Got a question for ya CJ- can you tell me what you did to midify the wedges to work without the rubber sandwich? I seem to remember having to cut a little tab off the spring bolt because it was so long that it hit the axle tube before it was seated on the pad. I know that my shims have a large hole in the center to accomadate the rubber mount. I assume you had to make some sort of bushing to fit in the hole to fit everything up? Whats the scoop?

 

[Cougrrcj]

Sandwich eliminator

Oh, sure! I just get the thing bolted back together after taking it apart yesterday to measure the wedge plate and figure out the angle and now you want me to take pictures and everything . Well, now you're gonna have to wait until I can get my cheap digi- camera up and running again to take a bunch of pics. (I suppose I might as well take pics of my restoration projects so far to get some of you off my back )

Give me a couple days and I'll see what I can do.

Anyways, the wedge plate has a 1/2" round raised section that pilots or indexes in the round hole at the back of the spring perch. That keeps the wedge plate in there. The spring center bolt is long enough that it goes through that big center hole that used to hold the sandwich mount and still can index to the hole in the middle of the axle spring perch. (Toploader, If you eliminate the thickness of the wedge plate, the spring center bolt is long enough that it will hit the axle tube.) Anyway, that keeps the axle from moving in relation to the spring. Now that everything is all locked together you clamp it all together with the u-bolts. You can still use your stock bottom plates if you want to, but I made mine to Mustang bolt pattern since I added a factory Mustang rear sway bar and that has a plate that goes between the spring and the bottom plate and has holes for the Mustang bolt pattern u-bolts to go through. I suppose I could have made the sway bar plates have slots instead of holes and still used the Cougar bolt pattern, but my buddy Terry had already made the 3/8" bottom plates to Mustang specs.

I did have to modify the wedge plates a bit since the Mustang bolt pattern bottom plates have the u-bolts closer to the spring perch. The wedges interfered because they were too wide. The wedge plates needed to be grooved or notched to allow the u-bolts to fit the Mustang bolt pattern.

This will be a lot simpler to see once I get the pics posted. Everything is all nicely painted black so the individual parts may be a bit hard to see, but I'll give it a try anyway. I'm definately not going to do the 'Family Handyman' illustration route and paint every piece a different color for ease of identification! LOL !

Milo

 

[72cat]

Does that mean you are going to take a pic of the front as well

 

[toploader]

Thanks for the info cj-- After seeing that most everyone here agrees that I should keep the wedge plates, I decided to put them back in. I know about the leaf spring bolt being so long that it hits the axle tube, because I had to cut a slight amount off when I bolted everything up. I took the wedge plates into work tonight, and took some round bar stock cut about 3/8" thick and pressed them into the plates. I then drilled a 1/2" hole in the center of them. This should work out pretty well. I did however forget about the stang shock plates bolt pattern being closer to the spring. I guess I'll just have to cut some grooves in the wedges where the axle pad locating flange is with a die grinder. My shock plates are off a '69 mustang. All in all not to bad of a job. Can't remember why when I did all of this 2 years ago I left them out--perhaps I had a brain fart