How much can you adjust T-bars...

[dwbiggs]

Before you need to get the front end re-aligned? 

[Challenger6pak]

I am not an expert but I would not adjust the torsion bars at all w/o a re-alignment. As soon as you move them you change your tire angle.

[dwbiggs]

Makes sense but I remember reading/hearing that there is some adjustability before you need to have it re-aligned...just can't remember what it was.

[Chryco Psycho]

changing the height changes the length of the tie rods , so you can always reset the toe in to 1/16 using a tape measure after adjusting the height

[dwbiggs]

changing the height changes the length of the tie rods , so you can always reset the toe in to 1/16 using a tape measure after adjusting the height

How does the tie rod length change?

I thought adjusting t-bars affected camber...guess that shows how much I know. 

[Chryco Psycho]

as the angle for the tie rod changes with the height it will adjust the effective length of the tie rod

[asm74]

How does the tie rod length change?

I thought adjusting t-bars affected camber...guess that shows how much I know. 

Think of a triangle.  As you change the length of any one side, you must also change the length of at least one other side. 

[Changin Gears]

Toe should not change during suspension travel.  If it does, this is known as bump-steer, and can be corrected.  It is caused by the tie rod ends not being parallel to the lower control arm.  It can be on one side of the car or both (each side should be measured individually).  This can be corrected by raising or lower the center link on the effected side by shimming the steering gear box or raising/lowering the idler arm.

Camber can change during travel because of the unequal length control arms.

Caster should not change.

If you are changing the ride height by <1" I wouldn't worry about the alignment changing.

[quagmire]

Toe WILL change with a change in ride height, as will camber.  As stated already the effective length changes as the angles change.  This is why caster and camber must be set BEFORE adjusting toe. And yes, any change in ride height will affect the alignment, to what degree all depends on how much change is made.

[Chryco Psycho]

 
 That has been my experience , adjust the height & toe is out slightly as well as camber

[dwbiggs]

Now if I lower my front an 1" or so, can it be re-aligned back to spec?  I have heard that some shops won't do an alignment until the car is at factory ride height....why is this?

[Super Blue 72]

  I have heard that some shops won't do an alignment until the car is at factory ride height....why is this?

   I'll take a guess    and say that the specs they have so the techs can have an easier time aligning the car to factory specs.  Deviations from factory ride height may cause trouble getting certain angles into spec as there are certain limits to the movement of the front end parts to bring parts into spec.  Some cars that are lowered purposely add more camber (negative camber) but wear of the tires becomes an issue.

Also a car that is not at factory ride height may have worn or broken suspension parts and may be difficult to bring the car into spec.

[Changin Gears]

Just remember, a couple of people sitting in the car will change the ride height, on a car with bump-steer, there goes the toe.  This is obviously not a big problem or it would have been addressed when the cars were produced.

[Challenger6pak]

Now if I lower my front an 1" or so, can it be re-aligned back to spec?  I have heard that some shops won't do an alignment until the car is at factory ride height....why is this?

When I worked at a tire shop the reason to keep everything to factory specs was for insurance and liability reasons.  A CYA situation.  The funny thing is that the specs were for bias ply tires.  Now we run radials.  I was told the alignment needed to be different for the radials but could not be done due to liability reasons. This forced the shop to send out an inferior product in regards to alignments on older vehicles.

[dwbiggs]

So how is the factory ride height determined?  Anyone have that info?  I'd like to know how far I can vary from that and still maintain adjustability within spec.