Proforged sleeved polygraphite LCA bushings!
Ok so here’s the update on where I’m at with replacing the lower control arm bushings in my dart. Thank you everyone for chiming in and continue to advise me. I pressed out a set of original OEM rubber lca bushings so I would have an outer and inner steel sleeve to adapt to my polygraphite LCA bushings. Now there seems to be an issue. The polygraphite bushing isn’t tight enough within the outer steel sleeve that goes into the control arm. It can spin when I twist on it. Also the inner steel sleeve that goes inside the polygraphite bushing also isn’t very tight and I can push it in and out without a ton of effort. The only fit that appears to be real tight is pressing the pivot shaft into the inner steel sleeve. With all the motion or spinning within the LCA is it even worth it to install the polygraphite bushings? Here are some of my thoughts/changes?
1. Try to find a steel sleeve slightly thicker for a tighter fit within the polygraphite bushing. This may spread the bushing a little and tighten it up within the outer sleeve.
2. Wait to try to install the proforged steel sleeved polygraphite bushings I ordered? I’m just worried that they will have the same problem.
3. Just for the LCA go with OEM rubber bushings?
4. If I do go with a polygraphite bushing and the pivot shaft doesn’t have a grease fitting will I be ok if I grease the s**t out of the bushing between the polygraphite and the steel before I install? I was told that any metal to metal surfaces shouldn’t be greased. I don’t drive my cars more than 2,000 miles a year or in rain.
See pic below.
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The "problems" you describe aren't problems. The poly bushings do not work the same way as the OE bushings, and that's why the poly bushings get a bad rap. People expect them to work the same way, and they don't. The poly bushings that were sold for years without the inner and outer sleeves also can spin within the shells. And, they NEED to. The old rubber bushings aren't all that different, they aren't bonded or anything to the inner and outer shells. It's just a friction fit between the rubber and the shell. It just so happens that the rubber is soft, so, it
tears before the rubber spins in the shell. The friction between the shell and the rubber is stronger than the rubber itself in that method of loading. So, when the suspension moves up and down the OE bushings just flex back and forth. That's why you have to tighten them at ride height, because they'll tear if they're tightened somewhere other than the middle of the range of suspension travel.
The poly bushings are harder, and the material is much stronger. The bushing spins in/on the shells before it tears, and actually, before it deforms much at all. That's how it's SUPPOSED to work, there isn't enough flex in the material for the bushings to work like the originals. It's also why they need to be greased, because the poly will squeak when it spins if it's not. The pins can also slide in/out of the bushings, which is why I recommend using adjustable strut rods with poly bushings. The material has less give, so, the length of the strut rods has to be more accurate. If you run stock strut rods and rubber strut rod bushings, you may see some movement at the LCA pin/poly bushing. It was there with the rubber too, but the pin now moves in and out of the bushing instead of there just being a ton of flex in the rubber. With adjustable strut rods that fore/aft movement is better controlled (there still is
some, because the arcs of travel are different for the strut rods and LCA)
The biggest issue with the poly bushings is using them with old outer shells. The factory tolerances weren't great, and replacement OE rubber bushing shells aren't any better. So, you have to check to make sure the poly bushings fit tightly into the shells. That's where a lot of the complaints about the poly bushings came from before, they wouldn't fit tightly into the old shells, so they'd wear out or function poorly if the fit wasn't checked, you couldn't just slap them in and go. The proforged poly bushings provide their own shells, so, that's a bonus, because the bushing should fit the shell just fine. That doesn't mean the bushing won't spin or slide in the shell, it just means the bushing won't flop around inside the shell. It should be a tight fit, but that doesn't mean the bushing won't spin. The inner sleeve seems like a waste to me. The reason being that the best way to use the poly bushings is with a greaseable LCA pin, not the stock LCA pin and proforged inner shell. No way to grease that later. The inner sleeve won't move on the LCA pin (or it shouldn't), but the pin/shell combination may spin in the bushing. It should be a tight slip fit, but it will still move (because something has to!). Which is why I use greaseable pins. If they start squeaking later, I can add poly grease.
If your plan is to use rubber bushings and stock parts elsewhere in the suspension, your best bet may to be use OE style rubber LCA bushings. If you're using adjustable strut rods, use the poly and get greaseable pins. Or, like Peter said, buy his Delrin bushings and don't worry about shells or grease. You still have to make sure the pins you use fit tightly (even more so than the poly) and I wouldn't use Delrin bushings with stock strut rods.