What's the benefit? For example a torque arm- an adjustable torque arm is going to allow adjustment of the pinion angle; correct? How often does that need to be done and what is gained by doing that? LCAs and panhard what is gained by having these parts adjustable? Wheel alignment? I need some insight to this.

 

Hello,

Yes a torque arm allows you to adjust the pinion angle of the vehicle. In most cases once you find a desired setting you do not have to change it again. If the vehicle is tracked a lot then changes may be made at the track for optimal performance.

Control Arms- In most cases adjustable control arms are not needed or adjusted. The times we do use them and recommend them is for larger tires and after market rear end installs. The control arms will allow you to move the rear end back or forward.. when running a larger tire such as a 29" tall or taller tire you may get rubbing in the front or rear fender well. The control arms would then allow you to move the rear end slightly to prevent this. Also some aftermarket rear ends (Moser 9" esp) do not sit centered in the wheel wells and using adjustable control arms will allow you to center it.

The Panhard bar controls the rear end side to side, changing the length of the panhard bar will move the rear end left or right. This is needed when the vehicle is lowered or when running a wider tire. The rear end from the factory usually sits off center a 1/2" so installing a wide tire may lead to rubbing on one side. The panhard bar would then allow you to shift the rear to prevent this.

I hope that helps some, please let me know if I can help anymore. Thank you!

Ryan

 

Those parts are made for people who adjusting things.

 

You can also set the thrust angle. When you get your car aligned, in stock form, they just center the toe, to match what the rear thrust angle is. If you have adjustable LCA's, you can zero the rear thrust angle. Between this, and an adjustable panhard, you then have all the adjustments needed to square everything up nicely (this all assumes the car is square...).

Adjustability is nice if you have tools/knowledge to use them. For the most part, stuff is a set it once, and then you only mess with it, if for some reason you measure it and it is off. All of the adjustable parts work this way, the weight jacks, etc. They aren't really there so you adjust it all the time. It is there so you can set the car up initialy, then pretty much leave it, unless you make an adjustment to change something at a racetrack.

I have seen a lot of posts about adjustable this and adjustable that. People seem to be missing the point of the adjustabllitly. Some adjustablity can also cause more problems then good, if you don't have the proper setup/tools. Like the weight jacks, and LCA's. If you don't corner-weight the car with weightjacks, you can end up with some really funky turning. Same with LCA's. If you try to just eyeball adjust them, you could end up with a significant change in thrust angle.

--John

 

Thanks guys!

John, what do you mean by thrust angle? Is that like pinion angle?

 

"Thrust angle is the direction that the rear wheels are pointing in relation to the center line of the vehicle. If the thrust angle is not zero, then the vehicle will "dog track" and the steering wheel will not be centered."

http://www.familycar.com/alignment.htm

 

So can a good alignment shop check the thrust angle and make the adjustments if needed, providing adjustable LCAs are installed? I know they base the front alignment of of the rear, but can they check if the rear is square to the car first?

 

Did you read the link I posted? It's all right there.

 

Informative link, thanx. Adjustable LCA also prevent binding you sometimes get with non-adjustable LCA. Later.

 

No they don't. The bushing is what binds. The only way to do away with binding, is to use a rod-end on one side, so that you have restriction free movement in rotation. Any rubber/ploy style bushing will bind. How bad the bind is, depends on the durameter of the matterial.

 

OK, u caught me, it was pictured in my head but didn't type it . Yes u need at least one rod-end with the adjustable components for it not to bind, thanks Dewey. Later.