Solid Poly Rear Trailing Arm Bushing OK for street?
 

Replacing my rear trailing arm bushings this spring.
Was looking into replacements from either:
OEM
Energy Suspension
Prothane

The aftermarket bushings are solid and so they don't have the same axis movements as an oem bushing. Good for less deflection, but probably harder on the bushing and other components in the long run. Was wondering If anyone has run into issues with the aftermarket or if I should just get OEM? I do like a tighter rear end

1998 Civic DX Hatch
Stock springs
Bilstein HD dampers
19mm rear anti-roll bar

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Hardrace or PIC/SONEM

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Is hard rubber "stiffer" than poly?
Looks like they allow a little more movement.
Are the Hardrace/PIC/Megan racing ones all pretty much the same?

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Do not use polyurethane trailing arm bushings. Just like you said, they don't allow the same axes of movement that the trailing arm requires, and they tend to bind up.

Just stick with OEM/Mugen/HardRace. Mugen and HR look pretty much just like OEM, but I don't think there have been any definitive answers as to whether they're stiffer than OEM or not.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Interesting remark, awaiting comments.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Mugen trailing arm bushings and toe control link bushing material is the same as stock...as they should be.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

As it was told to me, the Mugen are made in the same factory as the OE Honda ones (thanks tot heir relationship) but are in fact stiffer than the OE. The Hardrace as well as PIC/SONEM are not made by the OE Honda manufacturer but are definitely stiffer than OEM.

Here's a comparison between the OE (left) and PIC/SONEM (right) from my car:

Attachment 463289

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Seems the pic/sonem is almost solid. Wonder how much movement the 4 openings will provide/allow.

Anyone who has the pic/sonem bushing how does it feel? How hard is the material?

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

To me they feel fine. Those on my EG with 10k/8k and they are 100% streetable. I was in St. Louis this past weekend and was driving around with a 240SX owner who remarked how well the car rode with those rates and all upgraded bushings. I guess 10k on a 240SX rattles your teeth pretty good.

The rubber has more elasticity than polyurethane so even though they may use the same amount of material the makeup allows the bushing to have more give. Obviously not as much as the stock bushing but more than the polyurethane. This means no deformation like polyurethane, a longer life, and better streetability.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

To tell the truth I can't remember if my HardRace RTA bushings look like OEM or those PIC ones above. They're sitting in a box in my garage so I'll have to look at them later.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Thanks for all the info. I'm going to go with OEM. I value streetability. Most likely going back to my OEM 13mm SiR rear anti-roll bar as well. I think the stiff rear bar is what destroyed my stock RTA bushings in the first place. Although I've heard that those bushings are one of the first to go anyways.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

13mm is nothing, and specific for the (USDM) SI.

EDM/JDM EK4 has 15mm.

Those won't destroy those bushings any more than without rear sway.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Yeah my current original RTA bushings are pretty dry rotted right now, but they're not torn up (yet) and I've had the 22mm ITR bar on the car for probably 6-7 years I would say.

Sway bars do not put any stress whatsoever on the RTA bushings that I know of, and in fact it should help them last longer since the sway bar is limiting body roll, which limits how far those bushings have to stretch/move.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Checked my HR bushings and they look just like the PIC ones on the right above, which I believe are also the same as the Megan RTA bushings.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

There has been talk of HardRace supplying bushings/arms to Megan but I can tell you Megan and PIC/SONEM are not the same. Actually, HardRace and PIC/SONEM are not the same (different formula for the rubber) but I can't say for the HardRace vs. Megan discussion.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Yeah I've heard that about HR/Megan. I was just saying they look very similar if not exactly the same as my HR ones.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

I have a 19mm rear anti-roll bar on my car right now. Wouldn't hard cornering with a stiff rear bar and wider tires tear the bushing. I'm thinking side to side movement.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

That bushing isn't really for side-to-side movement but allows "twist" as the trailing arm pivots. As the car compresses the suspension, that side trailing arm comes up relative to the car. That bushing has to twist (move that inner bar like a see-saw) to compensate for that movement.

The rear trailing arm is at a fixed distance from the chassis via the compensator arm, rear lower control arm, and rear upper control arm. They don't compress so the trailing arm can't move in or out. If the trailing arm has side-to-side movement then there's a problem.

Am I making sense at all? It's had to explain without pictures and I feel I've just done a terrible job of it.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

I understand. It moves in more of an arc than straight up and down. I just figured it was the weakest link in a more aggressive than OEM set-up, and thats why it failed.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

They generally fail on lowered cars because they become permanently twisted. The bushing is always deflected and under tension on a lowered car, which causes it to fail prematurely.

Before reinstalling a new one, be sure to mark the orientation of the center pin *at your preferred ride height* and install the new one in that orientation. That will maximize the bushing's life.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

...and the postion of the trailing arm bushing also exerts is will upon the toe control links.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

I have been running es poly rear ta bushings on my crx for years now with no issues. Car has seen plenty of street time as well as track time at summit point. I noticed no uncertainty or unpredictable-ness that people always complain about. Works fine for me, and it's much cheaper and easier to replace than a press in solution like oem and others of the like. I'll continue to run them in the future, that is til I replace them with a completly solid solution like a spherical bushing.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

I bought 'PIC/SONEM' style trailing arm bushing for my car to replace 2 year OEM styles ones, and car feels almost as 'smooth'/soft as those OEM styles ones.

I'd say they're a win win, given how difficult replacing them are.

Update: These make toe adjustment very difficult, AND is biased towards toe out. Most alignment shops won't be able to get it in spec (toe-in/positive toe). Consider having them stick out 5 to 10mm towards the exterior side of the vehicle; from the upper part of the trailing arm housing. I recommend having out kit just in case.

And familiarize yourself with the following thread, if you do get toe kit.
https://honda-tech.com/forums/suspen...e-kit-2895853/

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Stay far away from these bushings. So I decided to get the special tool, the one that actually fits on both sides of the trailing arm, and used to be $300 a few years ago; $125 now.

I pushed these 5mm (3/16th of of an inch) outward away from the top part of the trailing as seen in the following picture, in hopes of getting toe-in. It was originally at 0 to 1 mm, i.e. lined up with the trailing arm. The picture is on the 'upper control arm' side of the trailing arm. Make sure lower control arm side is less than or equal to what you push opposite, in my case, I think it was 3 to 4mm. 5mm would definitely be the upper limit, and 3mm the lower limit in regards to UCA side.
I was thus able to attach 17mm bolts to the chassis/body of vehicle easily with the strength of my fingers. This was not the case in my 1st or 2nd attempt of doing these trailing arm bushing repair. The moog ones I later got, were the same, I.e. I have it sticking out 5mm, was able to attach it to the car easily. Both moog and the 'aftermarket design/solid poly design' i got, their bearing 'race' measured 40mm across

Now some of you may laugh at me but I did a DIY string alignment. The tires suspended and within 1 inch of accuracy within each other. I used the water level trick but forgot to double check myself. And of course I made sure all 4 tires were on 'slip plates' to allow suspension to settle.

String apparatus follows the same logic as the following post at this Miata forum, instead of the 4 jack stands approach. This negates the need of calculating the center line. Front and rear had wheel hub distance difference of 8.25 mm, instead of 2.5 mm (track width), LOL.
https://www.miataturbo.net/suspensio...2/#post1398008

Anyway the driver side (left side for those that live in North America), rear tire were still towed out (3 to 4 mm difference, over 0.4 degree toed out), and the passenger side was 1:1.

Bottom line, the engineers at Honda aren't stupid. Given this is a sports compact, the engineers did not design the bushing like these after market ones, because it would limit the toe range; although one could argue that Acura is 'luxury' and this aftermarket design would make the ride stiffer. Getting toe-in with these after market is near impossible, and would likely result in welding an 'extension' piece near where the inner 17mm bolt goes through. It's a dud.

Please save your time and stay the hell away from these.

Also the car handled better on my first attempt of the DIY alignment, but I did adjust the rear passenger camber by 0.6 degrees (From 1.6 to 1.0), with the ground not being perfectly leveled on all fours.


https://cimg3.ibsrv.net/gimg/honda-t...037a3a2c08.jpg

Edit: It seems the bushing should be sticking out by around 1.5/16ths (i.e. 3/32 of inch) instead of 3/16th of an inch. I had the car suspended on wood and had slip plates (to rid of suspension preload), and the bushing was 'twisted' as if it had been pushed out too far. On top of that I was unable to get toe in, with the bushing sticking out by 3/16ths of an inch.

2nd edit: I'd say 1.5/16" minimum to 3/16" maximum is okay, as I did not have any trouble attaching the 17mm bolts to chassis of the car. I had a shop make it 0", I.e. have the bushing line up with the exterior, and had immense difficulty attaching placing the 17mm bolts. I'd stick with 1.5/16", since the rubber was bending at an arch like position when at 3/16" away from the arm.

Re: Solid Poly Rear Trailing Arm Bushing OK for street?
 

Thanks for the heads up on this. Do you have a link to or picture of this tool you used? I'd like to do this job without removing the whole arm & brake lines off my car.