LCA Bushing Comparison

I finally got together some LCA bushings for a comparison. There are two different bushing styles - early and late. The rubber portion of the early model bushing is wider (along the axis of the bushing) than the late model. I suspect that the reduced width of the late model bushing is to allow the suspension to have more off-axis bending compliance (e.g., better flex) and probably reduced NVH.

Among the all the bushings, Moog bushings were the only ones that had "Clevite" embossed on the bushing. While totally subjective, I feel that among the early model bushings, the Moog was the best quality. The other two bushing that were made in India felt cheap.

For the two late model bushings, the Duralast seemed like better quality because of the use of a machined center sleeve and better dimensional consistency of the rubber bushing. Hard to say if its actually better. I suspect that the late model Duralast is a rebranded late model Centric 602.58011 bushing.

I tried to estimate stiffness of the rubber of each bushing, but I couldn't find any tools that could allow me to make any kind of quantitative estimate. Qualitatively, they all found about the same stiffness.

While I didn't have the Teraflex LCA bushings on-hand for this comparison, I'm pretty sure that those are the early model Moog design. Moog made some early model design bushings with yellow zinc plating, and this is what I think Teraflex is selling.

IRO says that the early model design is better. Their website shows a PN of FB543 which corresponds to the Duralast early model bushing that's made in India.

I like the the looks of the FP855 and then the FP543

I'm on the fence about whether to use the Moog K3131 or the Duralast FP855. The RC long arms came with Moog K3131s, and only one is lightly cracked after probably 7 years of service. The Duralast FP855 quality looks better though.

I made some measurements of some of the bushings and found some interesting things:

- The early (K3131) and late (K7419) model Moog LCA bushings have a small diameter of 2.245" and a large diameter of 2.285".

- The late model Duralast FP855 has a small diameter of 2.255 and a large diameter of 2.298", so it is a full 0.010" larger diameter than either of the Moogs. I suspect that they did this intentionally because the sheet metal control arms likely have a tendency for the bushing hole to open up over time.

- The late model bushings seem to have a 0.1" longer body than the early model bushings.

- When I removed the early (K3131) model Moog bushings from my RC control arms, I first had to push out the inner metal sleeve using ball joint press. It pushed through with some effort, but within the capability of the press. There was no evidence that the sleeve had been bonded to the rubber. It looked more like it was being held in place because the rubber was is in a compressed condition.

- Out of curiosity, I tried to push out the inner sleeve on a late (K7419) model Moog because it looked like the rubber had been bonded to the inner and outer sleeve. Sure enough, I could not get it to budge. I stalled an electric impact wrench using the ball joint press, so I put it on a hydraulic shop press. Still no luck with a fair amount of effort. If I had put more effort into the press, I might have been able to break the sleeve free, but if anything went wrong, parts would have gone flying across the room at high speed, so I didn't try too hard. Besides the sleeve not breaking free, the rubber went through a huge amount of deflection without damage. Its definitely one tough bushing. The Moog K7419 is definitely a tough bushing.

All that’s left to do is make sure you tighten the lower control arm bolts at ride height. As with all memory rubber bushings.