Been scouring HAMB past tech posts/ threads on suspension issues from others. Learning about bump steer, Ackerman, caster, camber, spring rate, tracking, center line/ perpendicular line ch***is set up, etc. . My head is about to explode. Bottom line. The set up on my car is damn scary when I drive above 60MPH. No fun in traffic Hitting any bump causes rear to jump & bounce and my *** to pucker. No rear shocks or panard bar using 40eye/eye buggy spring. No panard bar on front. Dropped 48 I-beam axle, hair pins tube shocks. Running bias tires. I did not build this car. What needs to be done to get this car to run down the highway without having to stay under 50MPH and worry about ? All help/criticism is appreciated. I want this to be a driver. Dave
Panhard or watt's link on the rear would be my first move. The rearend could be steering you on bumps.
why not triangulate your top linkage on your rearend? That would be self centering then. That and shocks
Get some suitable shocks (not TOO stiff) on the rear pronto! Also, do not run excessive tire pressure for the rear axle weight. Bias plys are stiffer to begin with and aired up too high they become real 'bouncers'.......combined with no shocks it's not hard to imagine it will hop all over the place. Ray
Get a couple of your fat friends on each side of the rear and have them jump it up and down. Is the spring flexing and the shackles moving out?? Looks like 11 leafs are a plenty. Something looks different about the shackles. Maybe just my bad eyes.
other than that very short upper bar , i can't see what is locating your rear end....could you post some more detailed pictures?
A panhard bar wouldn't hurt a thing. No shocks will add to the bounce problem as will the spring rate. I'm going to guess that it has a couple too many leaves. Something else that would other me is the length of the suspension links. They look pretty short of a streeter. I can't get a good angle on it but you may also have some pivot point problems. Everything wants to swing together of one link is shorter than the others and the pivot points are not set in the correct place it will cause some handling/ride ills also.
There look to be some short lower bars as well. The shackle angle is probably not letting the spring move much and it appears awfully stout (STIFF) to begin with. Shocks are a must to keep it from bouncing all over. I would re think that entire arrangement
It could just be the pictures, but the "shackles" don't look like shackles to me. They appear to be welded solid to the arms off the rear end and are just providing a place to bolt the spring to. A side shot or better detail picture of the rear "shackles" could help determine that. I would expect a real harsh ride if your spring is mounted to rigid points on the rear axle. The spring can't flex right as it travels.
The shackle's look like they are solid? do they pivot? I bought a trailer once that looked really nice and the shackles were welded solid!, I found out after putting 500 pounds in it and it tore the shackles off the frame, the spring wont flex when it cant expand. Stiff spring, no shocks, bias tires, short trailing arms, probably want to just start new. Rear end brackets to locate the spring, shackles, shocks and longer arms to start with, then dial it in. Then go 70 mph
I thought that initially as well. But I wasn't sure so I didn't say it. Would like to see a better shot as well. There is nothing wrong with a straight 3 link. Done in race cars all the time, the problem is a lack of lateral location, like a Panhard or Watts. My guess is that if the rear spring weren't all bound up that thing would be like the tail wagging the dog big time!
Holy ****, I ***umed that I just didn't see them, but on further review they do look solid. "bump steer, Ackerman, caster, camber, spring rate, tracking, center line/ perpendicular line ch***is set up, etc. . " none of that will fix the solid mounted rearend.
Add another vote for this. a leaf spring suspension needs to have shackles to work properly. without them the spring cannot flex. the setup you currently have will eventually break the diff hangers due to metal fatigue where the spring is trying to move. A panhard bar will also help greatly. a three link like you have with only the leaf spring to keep it centered will let the diff move back & forth while you are driving it. also you need to have shocks. A panhard on the front will help also. I feel you pain, suspension & handling issues can be difficult to track down. And if you know who built the car, my suggestion is to find him & educate him on the fact that he set the rear up wrong before he builds another unsafe ride.
They do look solid. That thing must ride like a hay wagon. Add another bar on the top and triangulate. gives you a 4 bar and keeps the rear centered. Shocks are a must!
Looks like too much spring ( too many leaves ). Main and secondary springs are too long, not enough shackle angle. Need rear shocks. Also need rear suspension triangulation or lateral position control.
All of the above, plus who fabbed those outer brackets and the steel bracket's on top center of the rearend housing? That cast-iron center section and those steel bracket's won't last long when everthing get's to moving around. Start fresh.
Cross steer front MUST HAVE a panhard rod. Rear suspension could be helped by one also, the addition of shocks will help a great deal. The clevis on the upper bar should be changed out to something more suitable like a HEIM or four bar end. But while you are at it, changing to a triangulated arrangement at the top would solve many issues.
I don't think a panhard with cross steer is written in stone but proper spring pre-load and shackle length/angle is..At the rear I can't see well enough to judge if shackles are welded or not, good suggestions have already been made..If the frame ends at the spring [looks like it does] I am wondering what is supporting the battery and the gas tank?..
I went and looked in his profile. It is not solid mounted. triangulating the upper, like has been suggested, would probably help. As long as the welded to cast mount is up to the task. and a better shot of the front.
I drove a basiclly stock 35 ford around without shocks and it was a nightmare at higher speeds. Added shocks and now its a dream to drive.
Looking at that picture, I'm pretty sure the shackles are fighting movement due to angle. There is noting wrong with the three link, quite common in dirt track and road race cars, but they do always use a panhard or Watts link. I would also get rid of the clevis' as they are going to cause bind in roll or articulation.
That rear end, the way it is set-up now, effectively has FIVE links. The shackles, the way they're extended forward on the fabricated brackets, cons***ute TWO upper links. The middle (upper) link, has become a THIRD upper link of sorts, and is of a different length. REMOVING the CENTER link would probably help matters. IT is the "binding" element. That whole mechanism really needs a "clean sheet of paper" re-design. I'd personally shoot for four, longer links. I'm amazed something has not broken before now. From the picture, the front appears similar to thousands of other totally functional hot rods. Model A thru '40 front ends had NO panhard rods. DD
Getting to the front end, it looks as though the spring eyes are resting on the top of the axle. Could be just the angle of the photo, but I would still check that too.
Took a couple more shots of the rear for clarification. The 2 bottom rear suspension links, along with the center link are 11 ½ long eye/eye, clevis on axle ends, rod ends on frame mount. The rear shackles pivot alright. Shackles move out when pushed down from center. Push down hard on one side & the rear tire appears to move back. Most of frame made from 2x3 sq. Rear uprights are 2x3 with a 2x2 rear cross member. After step, front clip is 2x4 with a 2x2 cross member for the front spring. When driving, jam / door gap varies.
Removing the upper link would mean there is NOTHING controlling rotaional movement of the rear end except for binding against the shackles, this would be a HUGE mistake. Sounds like the entire frame is flexing !!
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