Polybronze bearing question

[Canada Kev]

If one were to install polybronze bearings, are there any NEGATIVE effects? I understand that they will reduce friction, allowing the suspension to do what it's supposed to do and promote a more supple, non-binding compliant ride.

The worry I have is that they will transfer more harshness due to losing the give of the stock rubber bushings. Is this a good upgrade for a car that spends most of its time on the street?

[ossiblue]

Don't know about the ride harshness, but you may consider having to grease the bushings periodically a negative since the other bushing options are service free.

[vash]

i put them in my car. there is some harshness. but it isnt that bad. and my completely silent rear suspension now has some creaks, bumps, and groans. tiny ones, but i do hear stuff now. definitely a case of "no free lunch". i keep everything greased up properly, but i think the poly part is making noise against the car...i had to use some poly sealer on my car.. as per the instructions. some cars take some jamming and cramming to get the part into the car. mine were on the loose side.

[brads911sc]

I have them on mine. no issues to date...

[SteveinTO]

I've had them on my '82, front & rear, for three years. They do require a squirt of grease now & then, but otherwise no issues. Way quieter than the 25 year old rubber bushings creaking and groaning. I don't notice any additional harshness except when driving over those freeway dots. Overall I think they give a much more precise pick up point and they rotate much more smoothly than the rubber (I know, the rubber doesn't rotate).

[TT Oversteer]

I have a set of PB bushings on my car and I like them very much. I would not describe them as harsh at all. Mine do not squeak or creak; they are silent.

There are always negatives to anything in life I would consider the installation to be a little tricky to do correctly. These must be set up with correct shims or washers so they do not bind when everything is torqued down. As stated above some have a loose fitment which requires the bushings to be glued into the torsion housing with polyurethane caulk. You may need to do a little grinding of the welds around the torsion tube to get the bushings to seat properly.

The maintenance is pretty minor; just a squirt of grease with the zerk fittings every six months or so.

Cost could be considered a negative. These are not cheap.

I would consider these bushings as part of a suspension SYSTEM in which you want to upgrade the whole suspension and not just the bushings. If you're looking for a lower cost, no maintenance, easier installation solution I would consider neatrix or Elephant rubber bushings. But for precision and overall "coolness" the PB's are the best.

[don gilbert]

I have had mine on for almost a year now. Before the P/B i had the hard plastic bushing on for a year. No comparison between those two, PLASTIC SUCKS on a 911 suspension. I think the P/B was one of the best improvements on my car, and i have improved everything, down side? as posted above they are expensive, but worth every penny. From now on ever car we do will have P/bronze

[C4 Pazzo]

... and my completely silent rear suspension now has some creaks, bumps, and groans. tiny ones, but i do hear stuff now.

I found that if I greased them with the suspension loaded, I got groans from the rear. After I greased them with the rear unloaded, the groans stopped (thanks to Steve Weiner for the tip).

[cmonref]

I found that if I greased them with the suspension loaded, I got groans from the rear. After I greased them with the rear unloaded, the groans stopped (thanks to Steve Weiner for the tip).

Now THERE is a tip I can use! Annoyed by the bumps and clunks, I had figured the next greasing would be to S-L-O-W-L-Y push in the grease so it would flow down the grooves instead of squirting out the side and causing me to stop.

[ossiblue]

Originally Posted by C4 Pazzo

I found that if I greased them with the suspension loaded, I got groans from the rear. After I greased them with the rear unloaded, the groans stopped (thanks to Steve Weiner for the tip).

Good point. We old timers remember the Zerk fittings and chassis lubes from our teen years and know about unloading the suspension but "grease-free" cars have dominated the market for over forty years now and it's becoming a forgotten practice. Your little reminder is valuable, indeed.

[vash]

Originally Posted by C4 Pazzo

I found that if I greased them with the suspension loaded, I got groans from the rear. After I greased them with the rear unloaded, the groans stopped (thanks to Steve Weiner for the tip).

great tip!!! i am going to try it!

[RSTarga]

I went with the elephant rubber bushings and am very happy with them for my street car. Of course the roads here in tx are not very smooth.

[Gordo2]

I refreshed and upgraded the suspension on my 83 Targa last year. The quality of the poly bronze bushings were nothing short of impressive.

In addition to the bushings, I stiffened the suspension up with larger T-bars and heavier sway bars (among other things).

My car actually rode smoother through turns, dips and minor bumps, but definitely transferred some new noises when I ran over harsh bumps: more rattling of the the doors and interior components compared to stock.

I think the increased rattling is due to the stiffer suspension components/not necessarily associated with using the poly bushings.

I've been very happy with the overall results of my suspension upgrades, and attribute part of the better ride quality to the bushings.

Best of luck, Gordo

[proffighter]

This was discussed here too:

911 SC suspension bushes

[Canada Kev]

Originally Posted by proffighter

This was discussed here too:

911 SC suspension bushes

And that was only a month ago. How's I miss that?

[911nut]

I installed them in my old SC.
Had lots of squeaking in the front until I installed the self-aligning mounts that Elephant developed later (a extra $200 and a do-over of the front end; a discount to the "test pilots" who installed the polybronze before the mounts were available would have been nice but nothing was offered).
Had lot of squeaking at the rear due to distortion caused by the shimming of the races. Elephant remedied this issue with thicker races. I chose to blue and file my races round, which fixed the noise problem but it required another do-over and I hate doing things twice.
I noticed no additional harshness with the polybronze system.