Thread: Ever seen this before?

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Yesterday I was taking some measurements to buy the parts necessary to put a new chrome front end on my roadster and I noticed the spring only had shackles on one end. It is directly bolted to the axle on the drivers side. Really weird. I've only driven the car a couple hundred miles or so. I didn't notice it while driving. It would have to move the axle sideways when the spring compresses and pull it back when it contracts.

Looks like it may act almost as a panhard bar to eliminate some of the side to side that may occur otherwise?

Originally Posted by MP&C

Looks like it may act almost as a panhard bar to eliminate some of the side to side that may occur otherwise?

I've never seen that driver's side spring perch before, and Robert's idea that it may be to eliminate the need for a panhard bar makes sense. I think I'd rather have a panhard bar to allow centering of the axle to the frame. Jason at Pete & Jakes is my go-to guy for questions like this.

It's called a "dead perch", was/is a popular setup in the dirt track circles (sure, pun intended) As Robert and Roger surmised it's intended to act similar to a panhard bar. It's been used from time to time in hot rod applications but never really took hold as a standard because not everyone is convinced it works as well for street use as it does for racing apps.

It occurred to me that I hadn't seen much reference to these the past several years so did a quick search to see if anyone still marketed them.. Sure enough, SoCal has them in their catalog: GT2 Adjustable Dead Perch Head Though from what I've observed most of the cars they build in their shop don't leave with one installed..............that might mean something too.

Originally Posted by Bob Parmenter

It's called a "dead perch", was/is a popular setup in the dirt track circles (sure, pun intended) As Robert and Roger surmised it's intended to act similar to a panhard bar. It's been used from time to time in hot rod applications but never really took hold as a standard because not everyone is convinced it works as well for street use as it does for racing apps.

Very interesting. Thank you.

I love this forum!

I'm wondering if I should re-use this method when I install my new chrome front end? My car does not have a panhard bar. All the panhard kit's I've seen require welding to the frame. Since my car is finished and painted, I don't want to weld/repaint.

I've been thinking as I drive this car that a panhard bar isn't necessary. But maybe that's because this setup has been doing it's job? I know lots of guys don't run a panhard bar, others say it's mandatory. I have very little experience driving a buggy sprung strait axle.

Thoughts?

You could probably get arguments both ways, mostly based on theory or perception, real or imagined. The basic notion is that the shackles will swing sideways when steering action on a cross steer car is induced. Of course since that means the car will be turning there would also be sideways inertia too. Is it enough to cause a problem with handling? Most people probably can't tell, but some probably think they "feel" it. Either the dead perch or panhard bar will limit that, though the dead perch could limit the arc of one end of the spring end movement causing slight bind and a resultant harsher ride. The panhard bar swings in an arc so to the fixed length axle there could be some tugging and side to side movement induced. Neither of which is very significant, but to those who might want to "feel" something it could be perceived. Stock Fords started with cross steering in 1935 and went a fair number of years in the beam axle era without a front panhard bar. Dirt track cars are pretty much in a constant turn, and ride quality/feel/comfort isn't a priority so fixing the spring at one end may be fine for that situation.

As for retrofitting a panhard bar, you could probably make the frame attachment bracket a bolt on with minimal paint disturbance if you were so motivated.

I would leave it alone for several reasons.

1. A panhard bar will also move the axle slightly sideways because it swings in an arc - albeit a small one.

2. If you add a panhard bar, you'll have to replace the dead perch with a standard perch, otherwise, there will be a bind.

3. It's working for you now. If it ain't broke, don't fix it.

I'd go with what you got. If after replacing the other parts it feels funky or behaves in a way you don't like then think about switching out to panhard and replace dead perch. If it hasn't been a problem yet, probably never will be?

I really appreciate all the input.

I think I'm gonna go with shackles both sides. I already own brand new components to do so. I had already ordered them since I'm taking off the old painted tube axle hardware and replacing with chrome I beam. This set up seemed a bit funky to me from the get go. I'll see how the car works w/o the panhard bar and add one later if I feel it's necessary.

Again, thanks for all the input, you guys are awesome.




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Look at the odometer and see how long its been riding down the road that way! If its a bunch since it was built I'd have to say it's worked well, if it has 50 miles on it and its been built for 5 years you might have found the reason they sold it! Best of luck Matthyj

11 years, 20K miles. I guess it worked OK.

You said you didn't notice it while driving.

Why then, change it to something you may have to further modify?

Originally Posted by firebird77clone

You said you didn't notice it while driving. Why then, change it to something you may have to further modify?

Because the old stuff is pitted and rusty and I already own new pretty stuff. The new stuff is installed now, you wanna buy the old stuff?