I’m getting closer to putting my the old desert cat back on the road, and need an alignment. Calling multiple shops, and a few have mentioned the use of or needing shims. I did not see or notice any shims as I replaced upper and lower control arms. Is it common to need shims with a new alignment?
I have found many the shops won’t align these older cars, because new alignment racks use a program that requires the shop to buy blocks of years ex.(60-69) (70-79) (80-89). etc.
Consequently the shop buys the block of years for the cars they are most likely to encounter (2000-2024)?
With that said, I have read some Cougar peeps suggesting 2005 Crown Vic specs.
Is anybody able to confirm what 2005 Crown Vic specs are?
Shims are a Generic Motors thing. Not needed on Fords.
For most, a Cougar equals a Mustang, and the 65-66 Mustangs used shims on the upper control arms to set the caster and camber. That just translates down the line if they aren’t familiar with the cars. By 1968 those were replaced with adjustable strut rods and eccentric camber plates on the lower control arm inner pivot.
For specs, use the “street” specs from Opentracker Racing. With radial tires, you need as much positive caster as can be dialed in without causing issues with the tire hitting the front of the fender.
1 Like
Those were replaced in 1967 model year - the first year for any Cougar but the second generation for the Mustang.
BTW the radial tire was optional; from 1967 onwards - for any Cougar. I would not use "all the caster you can " when specs are available that say otherwise.
I hope this doesn’t turn into a ‘what oil to use’ discussion’, but…
Caster helps the car center itself when driving down the road. I also prefer a good bit of positive caster. Several degrees is good (3-5 depending on your needs). There’s really no downside to excessive caster other than it’s harder to initiate turn-in (doubt you’ll get there with these cars).
The OEM suspension design was total crap. Shelby’s mod (which I’ve incorporated on my '67) was to lower the upper control arm mounting points. It lowered the front a bit and altered the geometry to make it less mediocre. such a mod had some loading issues on the ball joints (there’s a wedge kit to correct), but I digress.
With that mod I generally run -1/2 to - 3/4 degree camber, as the other gent suggested - as much positive caster as I can get (with a bias to compensate for road crown when needed- generally a little more positive right vs. left). I can’t imagine I’d run differently even stock (perhaps more so since the stock geometry is so bad). Of course, if you use big sway bars to stiffen roll resistance then you tend to mitigate the crappy geometry by not letting it roll over.
I’m unfortunately not home to cite the last alignment specs I used (hard copy in file), but I believe was a bit over 4 degrees positive caster, and alignment as I suggested.
The front end alignment specs are in every copy of the factory shop manual. If your alignment shop does not have them bring your own.
The original specs are really only good for the factory bias tires. Even though radials were an option, there’s no “radial spec” in the manual. The manuals are not infallible either, there’s plenty of errors, missing info and copy-paste from the previous year’s manual that doesn’t apply.
If anyone wants to go down a rabbit hole, Google caster trail. That’ll bring you into some deep info on suspension theory and design. Bias / belted tires deform at speed, creating more caster trail, so they naturally are more stable at low or zero positive caster settings. Radials deform less, and don’t generate as much added caster, so they feel squirrely and unstable with bias specs.
OP, you don’t need to take my word for it. Dig around, talk to companies like Street or Track, Opentracker Racing, Mike Maier or any of the dozens of companies out there that specialize in this front suspension system. They’ll tell you the same thing - increased positive caster with radial tires.
The factory shop manual gives alignment specs. If you are not racing do not deviate from the factory specs or severe and inappropriate tire wear will result.
I would say we need to determine how modified your front suspension might be before recommending stock or modified specs. Tire sizes also matter. A radial in the same size as the OEM tire is going to be fine on the OEM specs but if going larger and wider you may need to deviate off of what the book may tell you.
If its 100% OEM I would say to stick close to the factory manual specs, If running a larger wider tire, have lowered springs and/or shelby drop, or have aftermarket suspension go for the other specs as mentioned with more positive caster. These have proven to work on countless mustangs and cougars.
I have done the shelby drop and have 1" lower springs and have run the camber caster/specs that are recommended by street and track, open tracker etc and my car is just fine on the street. Tire wear is also good.
1 Like
This stuff is adjustable so it’s easy to add
and subtract a little bit and see if you can feel it or see a difference. You can measure toe with two tape measures and some straight edges.
In the shop manual I have it gives caster specs not in degrees, but distance in inches between chassis and suspension members. I guess the Alldata-type systems that shops use had these roughly translated into degrees (who knows if it was done correctly). When I let my alignment shop do the alignment to the specs in their computer it showed -0.8 to 1.3 degrees as the desired range. I can tell you from experience on radials this will make the car wander all over the road and have no return to center. When I went back and had them dial in 4-5 degrees caster it massively improved the wandering and return to center.
Maybe it has nothing to do with radial vs bias ply liking different casters, but those distance measurements being improperly translated into degrees at some point.
1 Like
Footnotes on “C” and “D” are suspension ride height distances.