Thread: Rear panard bar

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Looking under my 29 Ford roadster (for an unknown reason) I saw that my panard bar bolts at the 3rd member connection had come out. My panard bar bolts to the frame bracket on the right side then crosses over the drive shaft and bolts to the rearend housing. Looking at the proper installation posted by TCI I see that this bar is suppose to be mounted on the left side frame rail and then bolt to the same side of the rearend versus crossing over. My rear end is also about 1" farther to the left then the right. Sorry for being winded, but can I leave the panard bar as it is, reconnect it where it came loose and adjust the panard bar to move the rear end to center? Thanks for any help.

Jim Groves

That's just TCI's way of doing it. Reconnect it, move the punkin to the center, and you'll be fine. It doesn't matter which side of the frame the Panhard bar connects to.

If you are using a steering set-up where the drag link goes from the pitman arm to the drivers side spindle, then Henry Rifle is absolutely right---it doesn't matter. BUT---If you are using a vega cross steering set-up it does---here's why. The vega box and Pitman arm are effectively "fixed to the frame" on the drivers side. The other end of the drag link is attached to the spindle arm on the far side of the car, so by default, it is attached to the axle which moves up and down as the spring flexes. In a situation like that, your panhard rod should be fixed to the same framerail (drivers side) as the Vega box. Even with a perfectly engineered panhard rod, the body will move slightly back and foth as the rear spring flexes, and the panhard swings thru its arc. Normally, it is such a small amount that it is not noticable. ---However, if your rear Panhard rod is attached to the passenger side frame rail, it will exagerate this side to side moment, as it is working opposite to the panhard rod effect at the font of the car caused by the drag link.---Y'all clear on that now????

Thanks for the quick response.
I have a Vega box which of course is mounted to the drivers side. So The "fixed" point of the rear panhard bar should be on the drivers side versus the passenger side where it is now? What are the consequences of me leaving it "fixed" to the passenger side? And if I can leave it "fixed" to the passanger side does that mean that I can center the pumpkin using the panhard bar, or should I swap sides? By the way, which is it, Panard or panhard?

Thanks again
Jim

It's Panhard. I'm not much of a fan of panhard bars, much prefer a watts linkage. Your setup should technically, as Brian said, be connected to the left frame rail and the right side of the rear end housing for the reason he brought up...... Just one of the many reasons I prefer an IFS front and a watts linkage on the rear.... I hate it when the car does the watusi!!!!!

I agree with the technical explanation, Brian. However, most street rods don't have enough suspension movement to make it an issue. In Jim's case, I'd hook it back up and see how it rides before going through a lot of work moving the whole system.

if you are gonna be turning left all the time you want it to be hooked to the right frame.

We had a fairly extensive discussion about panhard bracket placement on the HAMB within the last couple of months.

General consensus was, frame bracket on the drivers side for the front panhard.

It doesn't matter which side the rear panhard bracket is on.

People reported their cars handled just fine with the panhard frame bracket on the passenger side.

If you plot the arc the end of the panhard swings in, there's not really much horizontal movement due to the limited vertical travel.

Leave it as is and enjoy the car.

I am giving advise based on sound engineering principles. If I was designing a chassis from scratch, thats how I would design it, because that is what is right. If something has been built wrong, and it works anyways, that still does not mean that it was done correctly. If it isn't causing any handling issues, then bolt it back in place and run with it. I jumped into this column and gave my information so that anybody considering adding a Panhard rod or building a new chassis would know why it was pivotted from one side of the frame as opposed to the other, so that they could do it the correct way and know why that was the correct way.---I never intended to be the final authority that dictates how street rods must be built. If you have something that you know is designed incorrectly, and choose to use it anyway because you find that "it works"---far be it from me to insist that you change it.

Thanks you guys you made me smarter. It seemed to handle just fine before and would get a little squirrely from the line but I attributed that to horsepower. It goes straight, fast and stops.
Regards and thanks again
Jim

Brian,

No one was knocking your technical expertise.

Brian, I'll echo Henry Rifle's words.

In fact, both of my roadsters have the panhards set up as you've noted.

The passenger side panhard frame brackets are working ok since there's no steering input from the rear axle's panhard when the suspension hits a bump.
Different story with the front panhard as you know.

Denny---I am not sure what the stock steering on a 34 Chev looked like. The one I had 43 years ago was a Master series coupe with the knee action front end---All I can remember is that I got an I-beam axle complete with springs and spring hangers out of a 50 or 51 Chev pickup, and it bolted right into place on the Chev Master frame. As far as the 9" Ford rearend, since you are running a Chev frame in your 34, I would stick with the leaf springs that it came with. That way you avoid the hassles of panhard rods, wishbones, aftermarket coilovers, the whole headache, and you can mount bayonet style shocks off the capture plate that sets under the leaf spring on each side. If you plan on racing it, set it up with a set of "slapper bars"

Forgive me for asking this again, but can you center your rear end using the adjustment of the panhard bar?

Last one
Jim Groves

You can if one end has a threaded rod end or 4-bar bushing. You just thread it out or in to to move the axle centerline. Note the threaded 4-bar bushing on the left of the P&J kit below.