[mrtleavitt]

Hey guys, are there any disadvantages to panhard bars?

If I'm following the idea correctly, it keeps the rear end from moving side to side in corners and such, right?

[Phatboy]

Yes thats right. It has two connection points. One on the framerail, and another on the opposite side but on the axle. A non adjustable bar is measured to perfection and installed between the connection points usually with heim joints.

This allows the axle to move up and down, but not side to side.

The caveat is that if the bar is not designed properly IE. its too short, it will do just the opposite of its intinded purpose and acctually MAKE the rear end move around as the suspension travels.

Usually this only happens in vehicles with very high suspension travel numbers, and a normal street car wont see this occurance.

Having said that, if your going to install one, do your absolute best to get the panhard bar/rod as close to horozontal as you can when the vehicle is at ride height. This will minimize any axle shift during suspension travel.

To show you what I mean. Do this. Hold your arm out straight to the side. Now move your hand down to your side using your shoulder as a pivot point. Notice that your hand takes and arc back to your thigh. If you go the other way it will move in an arc up to above your head.

A panhard rod works the same way. The further the suspension travels the more it pushes and pulls the end link(your hand) side to side.

Now do the same thing, but move your hand up and down only 6 inches. Note how little side to side movement your hand has. That would be an example of a properly installed panhard bar.

Here is a picture of the idea. Which is acctually a bad picture, because of the angle of the bar. When the suspension compresses even slightly this axle is going to shift to the left. And, when the suspension extends it will pull the axle to the right.



Here it is in opperation, which is a much better example, because the rod/bar is installed nearly horozontal. This design will work much better.


The dissadvantages show up, when the bar is incorrectly installed, or too short for the application. Then all hell can break loose. Literally!

Another application that does exactly the same thing, is more complex, but doesnt have the down fall of side to side movement like a panhard rod is a "Watts Link."

The picture below should explain everything.

[mrr1999]

It's all about the set up. Make sure it's done right if not the geometry will be messed up and the car will never perform right.