Wheels causing car to jump all over

[nba1341]

Originally Posted by THUMPIN455 The alignment is off. If they are unaware that cars built with bias ply tires had different specs than did cars with radial tires, then take it somewhere else. A 215 tire is not going to be that much of a problem. I have run 285s on the front and it doesnt do that. If they have the toe and camber set for bias ply tires, it is going to wander all over the place, because radials drive differently. Aligning an old Mustang is a bit more involved than the newer cars that are toe and go, and just maybe the guy they have doing alignments is unaware of the adjustments on the older cars. Its like finding a guy who knows carbs, its a rare thing to find someone who actually knows how to fix and tune the old stuff. thanks for the replies guys they took it down the street to the alignment shop which they do mostly old cars and they aligned it a pit (i believe) and also replaced the idler arm it actually drives pretty straight going down the freeway but any little bumps and what not and the car will be in the next lane, etc is this bump steer or what?

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[nba1341]

also all of my tires have always rubbed on the fenders when hitting bumps hard and my fenders have never been flared or anything


but seeing guys like tims65 with 245s in the back! and 225s up front! makes me wonder what can I do to fix this????

[Carlos Pineiro]

I'm guessing the tire size is 215 55R 17 all around. This should not cause any probs. Bad alignment will. Your car will shimmy with new rubber if it's not aligned properly, in most cases. The offset is important if it's a different wheel than when last aligned also.

If you have a lot of orig steering and suspension parts, shimmy can be felt if the bushings and spring perches are worn.

If you have wheel hop at launch, the torque is flexing your leaf(s), Traction bars will fix that and they're an EZ bolt on.

CP

[Tims65]

Originally Posted by nba1341

also all of my tires have always rubbed on the fenders when hitting bumps hard and my fenders have never been flared or anything


but seeing guys like tims65 with 245s in the back! and 225s up front! makes me wonder what can I do to fix this????

What alignment specs did they align your car to? Can you post them?

The wheels hitting the fenders, are a separate issue and may be due to the wheel backspacing. Can you measure the backspacing for us? Take one wheel off, lay it face down on the ground, place a straight edge across the back of the rim and measure down to the mounting hub. That will give you the wheel's backspacing.

Tim

[chris66dad]

Have to agree it is not the tire size.
I also believe it is an alignment issue
Other possible issues to consider:
Lower ball joints on the LCA are bad
inner tie rod ends bad
outer tie rods bad
Check the steering components for slop from under the car

Good Luck and BE Safe

[chris66dad]

For the issue of the front wheel clearance issue you have a couple of options.

Roll the fender lips to give you more clearance

Install Vario-Centric Camber Kit to the lower control arms. This will enable you to remove the shims from the UCA and this will pull the top edge of the tire in about 1/2 of an inch. The distance depends on how many shims you have in place
Here is a link:
http://www.mustangsplus.com/xcart/pr...5&cat=0&page=1

If you do this it would als be a great time to install adjustable strut rods to eliminate the rubber bushing issue and flexing. It will also make front end alignments MUCH easier.
Here is where I got mine:
http://www.rosehillperformanceparts....20Strut%20Rods


Just some ideas-options to think about...

Good Luck and BE Safe

[nba1341]

Of course they did not return my wheel key so I cannot remove the wheels :/

Guess i'll have to wait till wednesday to address this issue

[Tims65]

Originally Posted by nba1341

Of course they did not return my wheel key so I cannot remove the wheels :/

Guess i'll have to wait till wednesday to address this issue

Did they give you a print out of the alignment? If so, post it, so we can help. Your car is way to sweet to not get the steering just right.

Tim

[67mustang302]

Like Thumpin said earlier, it's HARD to find people these days that can do old stuff. I'd go a step further though and say these days it's getting harder to find people that actually UNDERSTAND what's really going on with cars. Most of the newer alignment techs are taught how to adjust newer cars and given a VERY basic understanding of the "big 3" of alignment, toe, caster and camber(and even then they barely understand their relationship to the car). But there's a lot more to it as well, such as steering axis inclination(which works with camber to create the included angle) as well as scrub radius, and that's without getting into how the suspension geometry affects the car driving down the road.

What's your wheel backspace? If you have too little backspace then your scrub radius will be larger which can cause the car to pull to one side under certain conditions such as bumps or especially under braking. A large scrub radius will also cause the steering wheel to try to kick out of your hand if one tire tries to lock under braking. It could also be a bump steer issue, or if your suspension is worn and you're still running stock upper arm locations it could cause a bit of pull if one side hits a bump and you have a small sway bar. It could also be multiple things working together.

One of the reasons newer cars track so straight and "drive easily" is because they run a crapton of SAI(steering axis inclination) and caster, but it makes them handle like ass. The caster helps with handling a tad, but the huge SAI screws up the contact patch during turns. It also creates a very small or sometimes negative scrub radius, so they track very straight even under heavy braking. Older cars and most sports cars tend to not run as much SAI, so as a result the cars are more sensitive to minor variances such as wheel backspacing and alignment settings.

Also check EVERY moving part of the suspension and steering for worn parts.

[nba1341]

Here is what I got for alignment specs

Front roadside 1/4 positive both sides

canister 1 1/2 - 2°

16 tow in


any help?