Why is it pulling left?

[steve91tt]

My 1971 240Z has developed a pull to the drivers side. It is bad enough that at highway speed the car will switch lanes in about 7 seconds if you let go of the wheel. I have checked the camber, caster and toe on the front end. Everything seems to be fine and balanced left to right. The tire pressures are all within 1psi of each other. The ride height is even side to side and the front is about 0.25" lower than the back. The car corners and brakes normally.

I'm scratching my head on this one. Any suggestions?

[buysell]

Just a swag, check the thrust line. Also check the distance between the front and back tire on each side.

-Justin

[doradox]

My 1971 240Z has developed a pull to the drivers side. It is bad enough that at highway speed the car will switch lanes in about 7 seconds if you let go of the wheel. I have checked the camber, caster and toe on the front end. Everything seems to be fine and balanced left to right. The tire pressures are all within 1psi of each other. The ride height is even side to side and the front is about 0.25" lower than the back. The car corners and brakes normally.

I'm scratching my head on this one. Any suggestions?

Try swapping your front tires from side to side. You could have a bad tire.

[cygnusx1]

Do what doradox says first. But when the front end is up in the air, make sure there is no drag when you spin the wheel by hand.

[steve91tt]

Lots of things to check. Thanks for the great suggestions guys!

[cygnusx1]

Oh don't forget to also check the rear wheels for drag. They can certainly hang up and pull the car to a side. If you don't find anything obvious, bring your car to a shop with a modern wheel balance machine that tests "road force". They can tell you if your tires rolling resistance is off kilter.

[boro92]

Is there any play in tie rod bushings or anything of that sort?

Alignment spec can be bang on, but any worn bushings will cause misalignment under load.

[Classicconnection]

Howdy Steve; I had similar experience with my '71 recently. It particularly was fun when I poured the coal to it and the front lifted and pulled hard left into the other lane. Yikes. I followed the book's torquing schedule for all suspension parts; some 65

lbs, some 90lbs etc. I also put the weight into the two seats to suspend the car as it will be driven, also per the book. Once done, it ran true. Just a thought.

[steve91tt]

I think I figured it out. This is my track car, I was adjusting ride height by playing with the height of the lower perch of my coilovers. I was checking ride height by measuring from the quarter panels to the ground. As it turns out, the bottom of my quarter panels are not aligned well with the suspension, side to side. In other words, setting ride height based on quarter clearance induced a pull. When I redid the height based on suspension hard points the pull went away. My bad. I ran 8 track sessions with the car this weekend and it worked great. No mechanical issues. Thanks for the help guys.

Edited November 7, 2011 by steve91tt