Granada spindles on that car?

lowercasesteve wrote:

'66 Mustang, 351w/T5, TCP manual R&P, TCP UCA, TCP strut rods, stock LCA.  All installed about 15 years ago.  GR8 shocks. It has not been aligned in some time, but tire wear pattern is normal.  Steering wheel has ~ 1/2" movement back and forth.  Wheels have no slack when I try to move them back and forth when jacked up.  Steering u-joint set screws are all tight.

I just started getting what feels like a bad case of bump steer.  The car bounds all over the fwy even though the wheel stays straight.  It is scary.  It suddenly veres about 6" one way and then bounces back. Today I drove it a few miles on the street and got the same results.  I know it is not toe out as I have lots of experience with that condition getting to the alignment shop in the past.  I am beyond my level of expertise.

In a week or so I have an appointment with a shop that has worked on the TCP products.  I just want to go in to the encounter with as much info as I can.  What thoughts abound out there?

Your problem could be in the bellow list:

Granada spindles but you can work around the wrong geometry and make them work fine.

Unequal tie rod length from passenger to driver side.

In proper caster alignment to "0" plane. 

Another problem that will cause this is set back on wheels. For example say if you were in a accident and rear ended someone and you're wheel was diven back this will cause set back.  What will happen is your wheel will always be chasing "SAI" (steering axis inclination). Our Cars are designed with what is thought to have the proper amount of SAI to make it so the wheels aren't chasing true center. Which is The true zero line from top dead center of upper Control arm and the lower control arm.  They way you can measure for set back the easiest Is stick your hand inbetween the tire and the fender towards the rear of the car and see how many fingers fit.  Then do the same measurement on the other side they should match.  If not you have a set back problem. 

Another  big thing that will cause this sense you stated it has new steering parts is, inproper camber adjustment.  This can cause excessive bumpteer. You can also use a string with a weight and go from 0 center line and Measure the middle of the tire this will show excessive camber roll.  Example: to many shims could have to many shims on the upper control arm and have roll out. Or not enough and have roll out on the bottom.  This would theoretically cause bumpsteer to force the car to the right of you have roll in on the top of the left drivers side wheel.   

If you can get the car on a relatively flat surface and do the ole bounce test on the front this should help shed some light on what's causing the bumpsteer problem.  You'll need someone to bounce the car and you or the helper to look at the car when it does the shimmy. 


I hope this some what helps there are several other things with caster and camber that will cause bumpsteer.

Last edited by True74yamaha (3/04/2015 5:17 PM)

I like this SAI description better https://m.youtube.com/watch?v=PVGnLI9Fx1Y

This goes further in depth.https://m.youtube.com/watch?v=x_GN7ePUBKg  on bumpsteer sai camber caster etc

  There was a grand am that the rack was 3/8" raised on one end. This cause extreme bumpsteer. I had to fix it in class the owner had just changed the rack after an accident.

Thank you everyone for your responses. 
I guess I did not put enough info in the beginning just as I thought would happen. 
I bought the car new in 1966.  It is now approaching 600K miles!  I'm thinking it is just getting old.  I'm the only one who drives it unless my wife has to under duress!

The spindles are the original 1966 spindles.  In addition, NOTHING has been done to the suspension in the last 4-5 years.  No accidents; no major pot hole incedents.  As far as I can determine there is no play in the steering or the suspension.  Looking at the TCP strut rods there is no  apparent wear in them.  Tires are about 2 years old and have not caused any problems in the past.

I am completely stumped.

Last edited by lowercasesteve (3/04/2015 6:09 PM)

darren wrote:

Tires? Ahh I see you added tire info. A rotation is free diagnostic unless staggered sizes. Then, I'd swap left/right front and test.
 

Fronts are 215's, rears are 225's.  Can't do the front-back swap, but I could do left right. I'll try that.
 

lowercasesteve wrote:

Thank you everyone for your responses. 
I guess I did not put enough info in the beginning just as I thought would happen. 
I bought the car new in 1966.  It is now approaching 600K miles!  I'm thinking it is just getting old.  I'm the only one who drives it unless my wife has to under duress!

The spindles are the original 1966 spindles.  In addition, NOTHING has been done to the suspension in the last 4-5 years.  No accidents; no major pot hole incedents.  As far as I can determine there is no play in the steering or the suspension.  Looking at the TCP strut rods there is no  apparent wear in them.  Tires are about 2 years old and have not caused any problems in the past.

I am completely stumped.

based on this info, your steering gear and/or rack is worn etc.
  

Last edited by barnett468 (3/04/2015 6:26 PM)

barnett468 wrote:

lowercasesteve wrote:

Thank you everyone for your responses. 
I guess I did not put enough info in the beginning just as I thought would happen. 
I bought the car new in 1966.  It is now approaching 600K miles!  I'm thinking it is just getting old.  I'm the only one who drives it unless my wife has to under duress!

The spindles are the original 1966 spindles.  In addition, NOTHING has been done to the suspension in the last 4-5 years.  No accidents; no major pot hole incedents.  As far as I can determine there is no play in the steering or the suspension.  Looking at the TCP strut rods there is no  apparent wear in them.  Tires are about 2 years old and have not caused any problems in the past.

I am completely stumped.

based on this info, your steering gear and/or rack is worn etc.
  

 
Very likely could you could easily test in a few ways return to center and shift from side to side without using the steering wheel.  He did mention quite a bit of slack in steering.

Ball joints or tie rods that have gotten dry inside and are binding can cause a car to behave terribly.  Just something else to try.  Be sure the tie rod studs on the rack and spindles are perpendicular to the angle of the tie rod body.  I also have a TCP rack and have seen the alignment jockeys tighten the nuts to secure them after an alignment and get them cocked in the socket so they bind up in certain positions.  ie.; they are already at max travel before the suspension even moves.