Need ideas 40 ford rolling side to side at 70

parallel springs in the rear,Roger Hart mustang II front end,no panhard rods

 

Any welding been done on the rear axle housing? Spring pads, shock mounts?

 

Sounds like the ch***is is twisting from the lack of good crossmembers/boxing..

 

If you raised the front up then you changed the toe-in. With too much toe in it will feel like you`re correcting both directions at speed.

I did the same thing on my `29 roadster and felt like I was on top of a fence trying to keep it from darting both ways. Corrected toe settings and all is good. It was so pronounced I thought I had something broke in the rear axle. Might not be your problem but it`s a cheap fix to check out.

 

Must 2. #3 deg pos. Sway bar back,good shocks, it will be happy.

 

get rid of the bias plies and quit sawing the steering wheel---you don't need sway bars to go straight...

 

Front end was realigned by the same guy that did it before,The owner has installed this same front end on a few cars all with no problem.After talking to some people and thinking about it I believe the Roll center has changed by raising the car and we will try a sway bar in the front and check the rebound in the front shock. Thank you. I will report my finding after.

 

You've never said how far it was raised with the coil overs.
If you jacked it enough to change the roll center that much you probably have other issues now that are consequences of that change. If it were me I'd be looking at what was changed immediately before the problem showed up and stay there.

 

You can realign up or down, but you must start off with the lower A ARM level with ground. If you raised the car the arms moved also,you changed the height.
I don,t know what my lbs springs are, They are from heights 1939 ford with narrowed a arms. If it was ok before lower it back to were it was and but bigger tire.
If dropped spindles put stock ones.

 

I'd try a different set of tires..borrow some to try, to me its tire related..

 

Sway bars front and rear,,the old sedans are kinda top heavy and the sway bars,especially the rear are needed. HRP

 

the car is obviously top heavy. I say chop it to lower the center of gravity

 

Might as well section too?

 

I agree, mine likes 80 much better.

 

Have you checked the squareness of the wheelbase?

 

Car was raised 1 inch in the front by adjusting coil overs ,rear stayed .

 

Some good input here. What have you checked of the ideas posted?

 

Yes,some we plan to check all and then probably add the front sway bar if all checks out.

 

Front end geometry, has to be correct , sounds like it's all fugly up !

 

All what he said above, plus too much toe in can also be a pain.
I'd be interested to know how and where the rear leaf springs are located.
Too close together could help produce the sway, plus ensure decent tire pressures all round...

 

raised front end changed caster

 

Question do you have dropped spindles.
You only have 2 ways to lift car.
Stock spindle if you have dropped ones.
2nd go to larger dia tire.
If a arms are not level your toe in gets worst as it goes up and down on road.

 

Pretty much !!!
Maybe refit the crossmember so the car works. since Trans is bottoming out I'd be interested in seeing how its put together.
If there's stock spindles and no room for bigger tires you don't have a choice.


The control arms need to be where they are designed to work. PLAIN and SIMPLE. If you ask them to do their job in someplace they weren't ment to work then the entire system needs redesigned.

 

X2 for sure----I have been past 70 who knows how many times and no problems. Parallel springs---and sway bars.

 

If you want to check the spindles.
dropped is more in the middle of the ball joints from top to bottom.
Stock is more to bottom lower to ground from center of ball joints.
about 2" difference.

 

I heard Cadillacs do this, but not until they get up to around 95...

 

Post a picture of the lower control arms. That will tell the tale.

 

It has coil over on the front we raised the spring bottom to raise the car and had it realigned.

 

I am looking for the angle of the arm. By raising the car, you changed the angles of all of the control arms. This raises the roll center of the car. To high in relationship to the center of gravity of the car, and you can have disagreeable results.

 

If the caster was not enough would that cause ill handling at higher speed?