Thread: ? on panhard bar / steering damper

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Getting my frame ready, and in doing some reading, I've come up with a question. I've got a dropped I-beam axle with hairpins, and have been studying a book by SoCal about building chassis.
They talk about panhard bars and their necessity with a I beam axle, but they also talk about a "steering damper", and don't make it clear if this is the same as a panhard bar, a replacement for a panhard bar, or to be used in addition to the panhard bar.
What do you guys suggest?
Thanks,
Randy

R.A....... a steering damper is different than a panhard bar. The damper is a hydraulic gizmo that is essentially a shock....

http://www.est1946.com/index.asp?Pag...n=Custom&ID=11

this site has an article about dampers (not dampeners). SoCal usually does both a panhard and a damper as I remember.

Do you need a damper? Many cars do not have one and drive just fine......perhaps others can comment that have tried it both ways.

mike in tucson

Resin addict---To clarify things a bit---. On any I-beam style axle with transverse leaf spring (any early Ford), the frame, body, and engine is suspended by the spring shackles which attach the ends of the spring to the spring perches. Under adverse conditions, and especially with a bit of wear on all of the components, the entire car can actually "swing back and forth" on the shackles. At any speed above 20 MPH, if this starts to happen, it rapidly begins to amplify itself untill the car will virtually shake itself out of control. This phenomenon is called "shackle rock", and is a truly terrifying experience. A Panhard rod is simply a link that is pivotted off the frame on the drivers side of the car and off the axle assembly on the other side of the car. This lets the frame move up and down as the spring flexes, yet prevents it from swinging back and forth on the shackles.
A "dampner" is essentially a shock absorber mounted crosswise, with one end anchored to the drivers side of the frame and the other end mounted to the axle on the far side, and it works in conjunction with the panhard rod to farther dampen any harmonic vibrations that would cause the front end to "shimmy".
I have always used Panhard rods on the hotrods I build, and have never found it necessery to use a "dampner".
Not all cars will need a Panhard rod on the front, but some will, and its a heck of a lot easier to put one on while building the car, than to have to add one after everything is painted and finished.
There really is no way to know beforehand whether your car will need one or not, as there are so many variables such as engine placement, tire size, wheel offset, weight distribution, etcetera.

robot is correct and so is brianurpnow!

To add to this topic...you simply need to understand the intended use of a panhard bar vs. the use of a dampening unit to know which one (or both) you will need.

First, when splitting a wishbone and using a dropped axle, you will need (and want) a panhard bar. The panhard bar keeps the axle located and prohibits sideways movement...thus eliminating or minimizing bumpsteer.

The dampener on the other hand...doesnt control the axle movement. It helps control the side-to-side wheel movement. I have one of the SO-CAL dampening units and it does help. With a Vega or Unisteer cross-steering unit, any bump can increase "road feel" to the driver. Four-wheel drives usually have a dampner to reduce steering wheel movement when driving over bumps, rocks, etc. While they arent cheap (only $35 in black...but $70 for chrome...) they do help minimize sideways movement of the wheels.

So if you are asking for advice...If I was building a new rod, I would certainly install a panhard bar. And I would add a dampner if I could afford it and had the room within the chassis. I would also recommend a stabilzer bar, other wise known as an anti-sway bar (Chassis Engineering makes one for the 28-34 dropped axles). With all three of these technologies at work for you, your hot rod will drive and act like a high dollar sports car!

Why not put a rigid mount on one end of the spring? Make it look like the shackle, but solid on top, bushed on the spring. The spring then acts as its own panhard bar. Most suicide front springs are very nearly flat, so bump steer wouldn't be a problem.

Thanks for the clarifications guys.
I knew I needed a panhard bar, and will have to weld the bracket for that before painting or powdering the frame, but wasn't sure about the dampner.
Is the dampner a weld-on bracket type item as well (like the panhard bar), or is it something I can add later if I see/feel a need for it? (although an extra $70 in the grand scheme of things really isn't that much I suppose).

Maybe the deciding factor is the tire you are running, also. I always run somewhat skinny bias-ply tires, because I like the look on a fenderless car better than radials. I have never run a panhard bar or dampener, and have had zero problems. Maybe with radials it puts a different hold on the road, and magnifies the shake some of you describe.

My '27 roadster is as basic as it gets: Dropped '32 axle, hairpins, '56 ford truck steering box, and it tracks right down the road. I'm running 5;60 x15's on the front, and it steers and handles like power steering.

But like the others said, it's easier to add it now berfore the pretty stuff gets sprayed on.

SO-CAL's Dampner simply clamps on without any welding. One end clamps onto the tie rod and the other clamps onto the passenger-side hairpin or four-bar. So if you select that unit, you can always add it later. Again, it is there only to add driving comfort as it "helps" keep the wheels from moving back & forth.

The reason I have found both the panhard bar and dampner useful is I put a lot of highway miles on this hot rod. I certainly am not saying you "must" have either... we have driven this car over 200,000 miles without either a panhard bar or dampner. But now that the technology is available and cheap (relatively speaking to the cost of the car for safety sake), I can see no reason not to have them on the car.

When you stretch it out at 80+ mph for a day or two, these really help you relax and have more confidence in your rod. And with today's traffic and road conditions, I need all the relaxing I can get!

I've heard the Volkswagon Bug damper looks very similar to the SoCal damper and a lot of builders are using it.

Like other V-Dub goodies, the price is pretty reasonable.