Do I need a Panhard bar in the rear, with transverse leaf and parallel 4 link...32 Ford/Ford 9"/new, boxed frame? Thanks, guys......
Yes,unless you have something else to locate the rearend you need a panhard bar.A parallel 4bar will not locate the rearend.
in my opinion, no, when you side load the rearend (corner hard) it pushes the spring opposite of the turn (trys to push the spring under the car) and it actually preloads the outside wheel, you don't get this effect with a panhard bar and transverse springs
The rearend will still occolate side to side by swinging on the shackles. If you have sufficient tire to frame clearance so the tire doesn't contact the frame while cornering you 'MIGHT" get away with out one. Frank
On my '34 pickup I have an Ibeam two link with a 40's front spring on the rear with no panhard. Sometimes when I would thrash it really hard through twisty, curvy backroads, it felt a little "sloppy" out back. Nothing crazy or scary feeling, just a little loose. Sooo, wanting to always improve what I've already got, I added a panhard bar thinking it would cure the ills. It felt EXACTLY the same. I guess I was feeling the tire sidewall flex or something. No difference. So I pulled it off and haven't looked back since.
Yes, you definately need one. Without a panhard, the rear swings left and right on the shackles and gives you what I call "squishy" handling. You aren't going to crash the car just because you don't have a bar, but you do need something to locate the rear if nothing else, to keep the tires from rubbing the 1/4s. Good luck, -Abone.
You don't "need" it but if your going to drive it hard your going to want one, It'll move around in the shackles. Terry
On my Bonneville car I hard mounted the spring on the right side and only have a shackel on the left side. just like the old midgets and sprinters. Don't really get into much cornering with it.
Unless your spring geometry is perfect you need one. I've had quite a lot of side to side movement in rearends with transverse springs running rear split bones that they would rub on the frame or bellypan in my case. The added panhard bar in the rear of a light car gives the driver the ability to turn the wheel all the way to the left, pop the clutch and find yourself going the opposite direction without the left front tire doing anything but rotating. But I have another car without one with good rear spring geometry, meaning the shackles hang at 45%, haven't found a need for one. I'm into another roadster now and I'm just going to put one in so I don't have to wonder why I didn't. I like cars that take corners flat.
Rich, is there some logic as to which side has the shackle? Did the various midgets have a consistent placement? Gary .
If the rear perches have been mounted to the original Ford dimensions, the spring shackles are Ford spec and the Ford spec spring is mounted under tension as Ford designed it to be from 1909-1941 and no Panhard rod is necessary.
IIRC, both of those used ladder bars that came pretty close to meeting at the trans cross member. This in an of itself provides some triangulation, when factored in with the spring, provides pretty good location characteristics. Now, a parallel 4-link, on the other hand, does not do this. The axle could "rock the shackles", making for a sloppy ride. I think that a panhard bar, or better yet, a watts link would be in order.
Midgets always turned left. So I guess they would hard mount the left side to put the main leaf in tension rather than compresion. On my car I did the side I was standing on at the time. Stock Fords had the wishbones to trangulate the axle. When you split the wishbones or go to a four bar, ladder bars or hairpins, I believe something should be done to resist side ways movement. I don't know of any new cars that don't do something to locate the rear axle. few new cars that have one.
It really gets down to the angle of the shackles when your car is on the ground. If the angle is around 45 degrees or less you probably would not need a panhard rod if the shackles hang more than 45 degrees or are almost verticle your car will swing on them and you probably need a panhard. I know because I could not get my rear spring mounts far enough apart and the shackles are more than 45 degrees and the rear wants to swing a little on really hard corners. Rex
That's right. As I explained it to "model A hooligan" (http://www.jalopyjournal.com/forum/showthread.php?t=379294), "Keep in mind that Henry's spring mounting already does a fair job of locating the axle laterally. Contrary to popular belief early Ford suspensions don't pivot on the centres of the springs, they pivot (quite freely, until they run out of travel!) on the spring shackles. If you extend the lines of the spring shackles you'll find they cross somewhere a short distance below the road. That's your real roll centre, the point around which the whole car pivots side-to-side, on these systems. The weight is above the pivot, so you'd expect the car to fall over, or at least go and sit on one of its bump stops, but if you take a close look at what happens you'll see the roll centre starts to move, or migrate, as soon as the car starts leaning over. It migrates in under the weight, and then some, so the car keeps tilting back to vertical." The steeper the shackles are, the lower the roll centre is below the road, the less unresisted roll you'll get and the more lateral shift. When the shackles get parallel to one another the roll centre gets undefined and there's no unresisted roll. There's no percentage in that, so I'd try to keep the shackles to 45° or shallower. Remember also that the length of the spring changes as it gets compressed and uncompressed, and that changes the angle of the shackles, steeper on bump and shallower on rebound, which changes the roll centre height, which changes the roll moment arm length. This is exaggerated if the shackles are short.
Do you "need" a panhard bar ? Well no, if soggy sloppy handling does not concern you, why bother. But if you are running decent modern radial ply tires and plan to corner your ride hard, then the stiffer the lateral location of the rear end, the sharper the handling will feel. It is really a case of what are you trying to do, and what is important to you.
That's a possibility, too. But any device used to locate the axle laterally - be that a Panhard bar, Watts linkage, WOB linkage, Mumford linkage, or whatever - will also locate the roll centre, and locate it other than where the spring shackles cross. In that case your approach to shackle angles will be completely different. To make sure that roll is resisted entirely by the spring I'd try to get the shackle intersection well away from the roll centre. It might be just as well to set them up close to parallel, so their intersection is some ridiculous distance away from everything and thereby ceases to be much of a factor.
True, with the original 'bones configuration. But when the triangle of the original bones is removed then something is necessary to replace Henry's original stability. All the way back to the 1950s (on the track)with "Henry's original mounting" Fords beat the hell out of others in handling, BUT, WHEN the wishbones were split or removed. that original stability was lost. It became immediately apparent that something was needed to replace the loss of stability with those modifications. Choose a panhard, _(or as RichFox points out)
Someone want to draw me a picture as to why split bones are different from non-split bones in axle locating geometry? I am just not following it. What is commonly called a "Watts linkage" is pretty well worthless on a hotrod with 3" of suspension travel. The extra slop, wear and weight of the three extra joints and structure offset any benefit you would see. A short 24" panhard bar would displace the rear about 3/16" with 3" of travel, hardly worth worrying about. Wikipedia has a decent page on linkages, http://en.wikipedia.org/wiki/Linkage_(mechanical) anyone who is designing anything mechanical would do well to understand the concepts outlined in the Gruebler equation, as well as the different types of connections. Bascially you want to make sure that each wheel has a single degree of freedom to move up and down while being constrained in every other direction. Mr. Ludd has it right about using a panhard bar and parallel shackles, which keeps the movement from being over-constrained.
No. When I put my A together I went with a 4 link and a transverse leaf. Many arguments were had at the shop about a panhard. I said I needed it, Jeff siad I didnt, Jon said give me a beer, and so on. Anywyas make a long story short, that was a year ago and I have had zero issues with out one
Back when the grease******* was an altered, the guy the originally built it had a Total Performance spring behind front end with a panhard bar added from the center of the suicide mount to the p***enger bat wing. Every time I would jack up the front end the axle would drop on the driver's side, but stay up on the pasenger side. I replaced the spring behind axle for a spring over axle to get ground clearence and left the panhard bar off. Now when I jack up the front end the axle drops evenly level. What was up with that, and was that something to do with the panhard? The front end always felt like it was in a bind until I replaced the axle.
Almost anything will work (in a fashion), but some things definitely work far better than others. If you are a racer, or at all interested in street performance, that is very different from being interested in what just looks cool, or is "traditional hot rod". Automotive technology has come a very long way in the last hundred years, but maybe you are trying to just restore it back to how it was originally built ? And there is nothing at all wrong with that approach either. But if you are after modern day standards of stopping, steering, ride, and handling, with and older style vehicle, then there are many fine points to suspension design that are well worth the trouble to use to the best possible advantage. Leaf springs are fine, if the incredible weight and non adjustability of the damned things does not concern you, but they are not really suitable for positively locating anything, for the precise reason that they are "springy" in all directions, not just up and down. Locate your axle any way you want with rigid links of your preferred geometry, and just use the springs and anti roll bars, as springs, to feed the vertical static and dynamic ch***is loads into your suspension. Rigid links isolated with rubber can be made extremely stiff, and they will not rattle, or wear out, and can give a crisp response to steering inputs, and a vastly smoother ride virtually free of road noise. But many guys are quite happy with bump steer, instability at speed, and soggy handling in an older type vehicle. It just does not have to be like that if you are building it up from scratch.
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