944J

I just got my car aligned for the first time since buying it.

It's a project 944na car that I got for very cheap.

Now I have spacers on the front and late offset 16" BBS RS wheels.

Questions:

1) The guy said he couldnt get the castor to align. Has anyone else had this problem? How should I go about fixing it?

2) The car steers and handles much much better after the alignment (suprise!) but the steering wheel still shakes at certain speeds. Any ideas?

The main reason I am asking is to determine if the car will ever drive without the shaking. If it won't I'll just part out the car. If I can get it to operate correctly then I'll continue fixing it up.

Thanks in advance!

Mr. Avionics

What is the condition of the tie rod ends? Not just the end at the wheel but also inside the rack. Any slop? Second and probably the reason for shake. Wheel balance. Mine shook too at certain speeds, good wheel balance cured it, after I replaced worn out tie rods. Just some thoughts.
Bill

944J

well he said that the castor was off and that the car didnt have any way to adjust it.

the car has probably been hit in the front right (passenger side.)

so I wonder if it is because of the wreck?

how much are frame machines?

and yes, the steering rack leaks...

but the only thing off is the CASTOR and I'm trying to see if its from the wreck, if so I'll just part out the car, if its the bushings or the steering rack, or wheel balance, then I can fix it... the tires also have different wheel balance.

I just dont think there is any point in fixing up a car that wont ever be able to be made to operate correctly...

Zero10

I would say the shake is from wheels out of balance.
Stupid question, but caster is the same as toe in, right?
If so, then damn straight these cars have a way to adjust it, same as any other car.
If it's another word for camber, then there's the eccentric bolts that attach the control arms. Either way, it's adjustable.

Hehe, how much are frame machines?.... about as much as a cheap house. No way in hell any DIY'er can afford one.

However, there are many shops that can check the alignment of the frame for a reasonable fee, I would expect in the neighbourhood of 1.0 - 2.0 hours labour to mount the car on a frame machine, and check the frame alignment.

Dave951M

Toe is exactly what it sounds like. It's like a person being pigeon toed. Camber is looking at the front of the vehicle, the angle of the wheels relative to a perpendicular with the ground. Caster is viewed from the side of the car and is th angle of the strut relative to a perpendicular line from the ground. For high speed stability, the strut should be angled back to the passenger compartment. If it is close to perpendicular, the car will be unstable at speed.

Your problem may be the strut bearing at the top is worn out and making it impossible to for caster to be set. Check that first.

Mr. Avionics

Caster and toe in are different. Caster is the angle of rotation of the steering nuckel when you turn left or right. Picture the front fork on a motorcycle, the point of rotation when you turn left or right is not verticle but angled back. This causes the wheels to track streight ahead when in motion. Too much caster and it would be very hard to steer, too little and the car would wander all over the place. Caster is adjusted by moving the aft control arm mount in or out, causing the ball joint to move forward, more caster, or aft, less caster. Toe in is to cause the wheels to run parallel when the car is in motion, to take up any slop in the steering by using the inherent rolling resistance to force the wheels back. Our cars use verry little toe in, indicative of a very tight suspension system.
So what does all this come down to? Again your shimmy is most likely due to wheel balance or out of round or bent wheel. Check the simple cheap things first. Always!
Hope this helps.
Bill

Mr. Avionics

Dave,
Ya beat me to it. hope all this info helps em.

Gerald Allgire

Tire out of balance can cause this. A brake rotor with some rust can cause this. Lubricate the sliders on your brake calipers. If they don't slide correctly the pad will drag slightly. Are your tires worn or cupped from driving with a poor alignment? That can cause the shake you've described. Do your brakes pulsate at all when you stop? Try swapping the front and rear wheels to see if your problem changes. I found that one of my struts was bent when I replaced them. I had always suspected that mine had been hit in the right front corner. Did the shop tell you what the caster was currently, or that they just couldn't set it? A better question; does the steering return to center after turning a corner? If so then you have enough caster, unless you're planning to drive it at very high speeds. Caster is more about feel than anything else. As stated before it makes the car more stable at higher speeds and returns the wheels to center. In a dirt track car we use it for other things too, but on a street car it's a setting that's more about driver feel. Hope this helps.