23 replies to this topic

[KW78]

You might consider this.  Once you have the parts changed, find someone that will do a "proper" alignment with a modern alignment rack.  The SAI function (Steering Axis Inclination) specifically is there to evaluate bent spindles, but if it is done half ass or not at all you won't get real information.  (IE your local 49.95 coupon alignment probably won't do)

 

Better yet, if you can find a race shop that does this with a modern alignment rack and scales for setup, it would be worth the stretch....  If you were in the Denver area, I would have a great recommendation for you....

 

Kyle

[RazerX]

We have TFB out here and my go there.  But essentially I am replacing everything on the corner and the frame checked out within 1/16".

[SaulSpeedwell]

You should do all your homework before throwing parts at the car.

 

First- try to insert a new bolt into the upper control arm mount on the subframe. If the bolt goes in easily, you are ok, if it does not, you will need to replace the subframe. The bolt should slide through with zero effort. If you need 2 fingers to push the bolt through, the subframe is bent.

 

Second- With the tie rod assembly attached at both ends, loosen the jam nut and watch the inner tie rod as you turn it. You are looking for any wobble. Resulting from bending. If it wobbles, replace the inner tie rod. If the inner tie rod is bent, replace the outer tie rod also. All the force required to bend the inner, went through the outer!!!!!!

 

Third- Measure the distance from the alligment cam horseshoes, side to side. Not from the cam bolts, but from the tips of the horseshoe. Measure all 4 pair. They all should measure the same within 1/8". If they do not, change the subframe. I have a tool to measure the rear subframes, but not the fronts.

 

Forth- This sounds kinda silly, but it works great. Compare the normal bends in the lower control arms left and right. Lay under the car and rub your hands accross both lower arms at the same time. Close your eyes and pay attention to your fingers. You will very often be able to feel any difference between the 2 sides.

 

Fifth- just replace the lower ball joint. They take a lot of abuse and are fairly cheap. Stay away from the cheap brands (ebay specials) they are not worth what you pay for them

 

Sixth- First step on inspecting the spindle is to check the brake mounts with a straight edge, as you have already done. If that is square, then you need a comparison spindle. Put the flat surface of the lower ball joint mount on the table. Compare the height and position of the upper ball joint mount, the tie rod mount (Steering arm) and the tip of the spindle. If any do not match a known good sample, replace.

 

Good Luck

Dave

 

This is a great post.  Add to this:

 

7.  Minimize (or maximize) or otherwise make equal the caster on both sides, and measure the wheelbase on both sides.  More than 1/8" different makes me lose sleep.  The short side of the car will always have trouble turning towards the long side of the car.

 

8.  Look at or put an angle finder on the tie rods when the car is on levels scales.  If the steerings arms are bent (or if the car has been modified fo less bumpsteer ), this should tell you.

 

9.  With caster equal and car level on scales at a given % cross, re-check % cross with steering wheel turned 90 degrees left versus wheel turned 90 degrees right.  There is no absolute tolerance I can give you for this, and it changes based on camber and what tires you have mounted, but I always wrote it down anyway because this is the "Weight jacking" due to caster and spindle geometry.  This helped me find a very (purposely?) bent spindle once that didn't match the other side.  That car had perpetual asymmetrical handling problems that % cross didn't explain. 

[Blake Thompson]

Don't forget the ball joint. I bent the stem on one several years back and chased a goofy alignment issue for hours before I discovered the problem.

Rick\\

 

this is common enough, and not obvious.  Good point.