Is everyone using those hard plastic bushings in their 4 bars? They don't seem to last too long and give a harder ride. Do you think if someone made a mold to pour softer urethane or rubber directly in the 4bar end incorporating the center sleeve in the mold, they would be better? I can't see why this wouldn't work. It would necessitate repouring them if they wore out. I am just looking for a better ride and longer lasting bushings.
You can get softer bushings, try an off-road shop. Personally, I'd try to find rubber bushings as most urethane ones are too hard IMO....
One thing that may work, if you have a local auto spring building company or warehouse you might take one of the ends with you and see if they have a spring eye bushing that will fit. Length won't matter as you can cut to length. May have to have the end honed or reamed to fit bushing. IF you do find one to work, write down application and part number then if it ever needs replaced, pushing old bushing out and new bushing back in. The ends of my 4 bar have the hard rubber ends on it and the above is my plan if they ever need replaced.
I agree. The urethane bushings suck. They just don't last from my experience. I'd try to get the rubber spring bushings.
I replace them with brass bushings. I also always have an end that allows rotation. Big rubber bushing or a rod end. With either the plastic or brass bushings, the end has to unscrew for rotation.
I'm pretty sure way back in the olden days, Pete and Jakes started using 60's Chevy panhard bars for their cars' front fourbars. And then when they went into production they had to come up with an easier way to produce a bushing than Chevy did. The urethane bushings can be made by a simple molding process and assembled by hand. Maybe Pete Eastwood can confirm this.
Pete and Jake in the "Olden Days" ? I must really be getting old ! Sent from my iPad using The H.A.M.B. mobile app
https://www.smooth-on.com/products/simpact-60a/ This product might work... https://www.overdrive.fi/forum/threads/pontiac-catalina-63-convertible-389cid.251058/page-9
A second cousin of mine told me about this stuff, years ago when it was unknown outside of mining: https://www.vesconite.com/ I have no personal experience of it, though.
Not sure what you guys are using, I have used Polyurethane 4 bar bushes for 30 years and they have no signs of being worn or failed, car gets driven regularly including many long road trips, maybe you have them under stress in their relaxed position. I have seen some of these types of bushings in early 60's Chev front ends that wear hard, but these are in a different load arrangement than a simple 4 bar.
Delrin is used for aftermarket suspension bushings and is available in bar. With all the existing bushings, I dont think custom would be needed unless your looking for a specific durometer. Can you measure the size? All kinds of bushings for trailer, equipment etc are listed by size instead of application like cars.
I was thinking of trying Delran. I have a small amount of it. I just thought if they were poured in the 4bar end and of a softer urethane or a two part pourable rubber, maybe this would help the ride. It would require 4 different molds to do all the ends on my car that I could make from Fiberglass laminates. I would be pouring them with the sleeves centered in them and trying to get the material to adhere to both surfaces. I feel the bushings that are available and also using brass leads to a harder or harsher ride. Thought I would see what everyone thinks.
If you have the equipment available to make these please post up details on your process. What material are you thinking? If you can post up measurements of your existing bushings, we can help look for available options. Would a properly sized rubber bushing work?
We experimented years ago with different hardnesses. We used 85 durometer urethane, which is softer than the more common 90 durometer that most people use. They had a softer ride, but the life wasn't as long.They would get sloppy after about 3 years of hard use on street rods. A friend made a 2 cavity mold, and he emptied his machine (where he made cane tips) every night into our mold. FWIW, that has been my experience.
I would have to make molds for each different angle of the bars. There would be two different molds to do my front bars and one additional mold for the rears due to different angles. I am going to start looking into pourable two part rubber trying to find the best for this purpose. I have two sizes of bolts through mine, 1/2 inch in the front and 5/8 in the rear. I would need to find rubber that would adhere to the bushings and the 4 bar ends. Might have to put wafers of a plastic material on the outer edges of the bushings to ease the rotation as they move.
@alchemy I was under the impression that Pete & Jake switched from the Chevy pan-hard bar bushings to urethane, because the rubber did not hold up to the continual twisting. Hadn't thought about the production standpoint, just remember the "repair" kit, they had back in the '70's that included a removal tool along with new bushing and sleeves. I don't think a lot of people realize how much the bars twist during suspension motion. Like Andy mentioned a "hard" bushing requires that you let the rod end rotate. Seen an imported rear four bar set-up with some sort of really hard bushings literally tear the frame mounts apart. Of course a too "soft" bushing will wear out to soon.
Looks like I will have to do some experimenting. I just thought they should be able to work like an A arm bushing.