Handling question

[peg leg]

My Demon has an unsettling habit of following tar strips, grooves and road surface irregularities.
The suspension is all poly, disc brakes with new lower control arms, rebuilt steering box and "E" body axle. No power steering.
It seems to sort of float aimlessly unless it is loaded on a center of the road "hump". The front end was aligned by a good shop.
I have measured (The only way I know) the toe, by measuring between identical tire grooves, and found 1/4" toe "in". The rear alignment showed the rear axle at 0.27 degrees.
Could insufficient tension on the struts be the culprit?
Any suggestions?

[cudabob496]

could simply be the state of the front tires? what pressure? how old tires?
alignment shops do occassionally mess up?
Aren't there other steering bushings etc that need to be replaced as well?
Was steering box rebuilt properly?
How loose is the steering wheel when car is stopped?
was it doing it before all the mods? if so, its one of the mods?
Try varying front end height?
how good are shocks?

[peg leg]

The box was loose after being driven, so I adjusted it. I now have about two inches free play at rest.
Tires are new Goodyear Eagle RSA at 35 PSI.
Shocks are new KYB. Disc brake conversion on front end.
The car was not driven before all the mods. I'm leaning toward trying to take more play out of the box, reefing on the strut nuts and moving the front wheels from one side to the other.
I wonder if those lousy air shocks on the rear could contribute. They tend to let the body roll when parked on an off level surface. The car will level itself from the shocks air pressure.

[340_GTS]

How does the idler arm look? They wear out, and introduce an enormous amount of slop into the steering linkage. And you are probably right about the air shocks. A sure-fire way to screw up the handling of almost anything!

[peg leg]

That's what's so frustrating about this issue. The idler arm and bolt are brand new Moog parts. I did see some slight movement last time I was under there, but dismissed it. Maybe the nut on the bolt is not taking up the slack enough. It is supposed to put a slight crush on the inner washer, right???
I'll get under tomorrow and try everything I know to find this thing. It's looking a bit like the air shocks are contributing. I put them on in a rush to get on the street. Big mistake!

[340_GTS]

Yes, torque the snot out of the idler arm bolt. The only slop you should have there is inside the idler arm itself (maybe a few .001") but no slop between the frame and the arm's washers/bushing. Factory manual says to torque the bolt & nut to 65 ft./lbs., but it can go a little tighter than that.

[cudabob496]

see how it changes with front tires at 25 pounds. I know this is not a recommended pressure, but it will show how much tire pressure could be contributing to the problem.

[ttraut@unlockit]

My 69 Roadrunner used to scare the hell out of me because of a bad steering box. I don't know if two inches of play is a lot or normal, but that's where I'd look (again!).

[cudabob496]

Originally Posted by ttraut@unlockit

My 69 Roadrunner used to scare the hell out of me because of a bad steering box. I don't know if two inches of play is a lot or normal, but that's where I'd look (again!).

I would imagine that any linkage component from the steering wheel to the
tires is suspect.

But I do remember running high pressure in front radials, that were not designed for high pressure, and getting the same response as noted in the original post. Then, if your suspension is set up wrong, it can make it even worse.

My Cuda, around 90, gets real lose and the front darts around on certain roads. I built a front spoiler and that helped settle things down!

[pressureangle]

This is typical of cars set to factory spec, with modern tires. Particularly with manual steering specs, you don't have enough caster. Here's a good article for review.

www dot allpar dot com/history/mopar/front-end-alignment dot html

dang blang link post limit.

[cudabob496]

Originally Posted by pressureangle

This is typical of cars set to factory spec, with modern tires. Particularly with manual steering specs, you don't have enough caster. Here's a good article for review.

www dot allpar dot com/history/mopar/front-end-alignment dot html

dang blang link post limit.

vacationing in Afghanistan???

[Rich Kinsley]

Since everything appears to be new I doubt that the steering box bolts are loose but that was one of my problems when I first got my car. It wandered all over and among other things I found that I could turn in the mounting bolts for the steering box by hand almost a 1/4". They were about ready to fall off. Since then I talked with several other guys who noticed the same thing. I check them frequently now. Also we ignore the specs and experiment to find a set=up that works for the car. I have a shop that understands all things are not equal and Kentucky windage is required occasionally.

[Ray Bell]

I think pressureangle has nailed it... you need more caster...

[peg leg]

You guys are great.
I know the box fasteners are tight. I'm going to attack the idler nut today, and test drive, then try tire pressure and test drive. After that, I'll attempt to kick the caster out a touch. Thinking about caster, it does act like caster is maybe neutral, virtually straight up and down. Kind of like walking on eggs.
If I find the culprit, you'll be the first to know!

[peg leg]

You guys are clairvoyant. I got under there and observed what I had previously seen, but did not think would affect the issue. Yes sir, the movement in the idler arm was very apparent, probably in the range of 1/8 inch! The guy who installed it did not torque the nut to spec. I put three turns on the nut before the wrench clicked at 65 pounds. Thanks for the spec 340 GTS.
Took it for a drive on the ruttiest road around here, and the car drives like it should now.
I also found the left strut nut too loose, (My bad) and torqued it to 90 pounds. This made no differemnce in driving.
Put a full turn into the box adjuster, and that change was effective, too.
Thanks very much, guys.