To PolyBronze or not...

[safe]

Are there really any alternatives?

If you were on a budget (like me) could you fit polybronze in the front and somthing other in the rear, or the other way around? The only thing I am sure of is new torsionbars all around (21/27).

[Sameer]

I'm using the Elephant racing polybronzu bushings for my front a arms and love it. Rear is stock for now but will be placing an order soon for the polybronze bushings for the spring plates. Go for it really. The steering feels lighter, sharper in turns and less road noise from these bushings. Forget the polyutherane bushings unless your going to track it often, too noisy. BTDT.

[Rot 911]

You could go polybronze in the front and neatrix bushings in the back.

[safe]

Neatrix is that like the original rubber och more like polygraphite. Where is the friction in Neatrix bushing?

[widebody911]

Hate to say it, but Neatrix bushings aren't all that great. They're an OK replacement for stock, but there really isn't any performance improvement other than getting back to stock compliance levels from worn OEM bushings.

Particularly in the rear, this isn't a job you want to do twice. This is coming from someone who done rear torsion bars something like 9 times in the past 2 months in an air-conditioned shop with a lift.

[safe]

Originally posted by widebody911
Particularly in the rear, this isn't a job you want to do twice. This is coming from someone who done rear torsion bars something like 9 times in the past 2 months in an air-conditioned shop with a lift.

Jepp, thats what I´m thinking...

[einreb]

Originally posted by safe
Are there really any alternatives?

If you were on a budget (like me) could you fit polybronze in the front and somthing other in the rear, or the other way around? The only thing I am sure of is new torsionbars all around (21/27).

I have polybronze front and back. If I had it to do over again, I'd do polygraphite in the front and think long and hard before doing putting the polybronze in the back.

The polygraphite in the front will require you to custom fit the bushings. You should also install grease fittings. Polybronze is expensive and you may also end up needing to get the additional hardware to stop them from binding. So, to do polygraphite is a lower material cost, but may take you a bit more time to install.

[safe]

Originally posted by einreb
Polybronze is expensive and you may also end up needing to get the additional hardware to stop them from binding.

How many has that happen to and why?
Cant that happen with polygraphites also?

/Magnus

[MotoSook]

Originally posted by safe
Are there really any alternatives?

If you were on a budget (like me) could you fit polybronze in the front and somthing other in the rear, or the other way around? The only thing I am sure of is new torsionbars all around (21/27).

If you are on a budget, then use the polygraphites. Install them correctly and you'll be fine! Even the polybronzes can be installed incorrectly leading to repeated install-reinstall-reinstall.....

[einreb]

Originally posted by safe
How many has that happen to and why?

I don't know... but it seems to come up a lot. I think it was a problem for some and thus chuck came up with a solution.

Originally posted by safe
Cant that happen with polygraphites also?

Other could likely respond better, but my guess is no. The polygraphite would just wear to the point that it would no longer bind.

Originally posted by safe
Even the polybronzes can be installed incorrectly leading to repeated install-reinstall-reinstall.....

You talking to me punk!?!?! Even correct installation can lead to repeated install/reinstall.

Souk is likely refering to the fact that I had a HELL of a time with my rear polybronze bushings. I had noise on one side and some very bad scoring on the other. I undid and redid it a bunch of times. It was finally solved by new inner bearings and races from chuck. I had several other look at the install and no one found any obvious problems.

My impression is that there are wear surfaces on the bearing that will never see additional lubrication other than if its unistalled and done manually. The grove pattern for the grease is typically used for sleaves that rotate 360, not the 20 (or whatever) degrees your suspension travels. there is also an outside lip edge with no means of lubrication that the race seats against. I suspect this was my problem area.

[911-32]

I was cheap and did polybronze on the front and Neatrix on the rear - if I did it again I would do Polybronze on the rear as well.

*However*, for a bit of prespective, the vast majority of club race cars in the UK are running around on nothing better than Neatrix - from my observations anyway. If you are just building a track day car then maybe Neatrix is plenty good enough. I would add that from what I read on Pelican it seems that people spend a huge amount of $$$ and time to prepare track day cars compared to the UK. Does it buy you any more "fun"? I don't know.

Richard

[einreb]

This is the bearing that was not making noise, but I pulled it to swap from right to left to isolate the problem and saw the scoring. This is after about 400 miles.



EDIT: The noise showed up at about 300 miles. I PM'd back and forth with chuck a number of times and tried all sorts of different 'fixes'. More spacers, less spacers, more shims, less shims, double check 'free play', et cetera. The noise would sometimes go away briefly (i suspect because i had manually lubricated the entire surface) but always came back. Just jacking up the car would sometimes briefly clear it. i suspect because it moved lube into an area not lubed by normal driving. I also swapped bearings left to right... and that didnt fix it either.

The 'fix' was to replace the inner bearings and races completely. I have about 400 miles on it now with no noise.

[widebody911]

Is there a better lube that can be used?

[911SCfanatic]

Tell us what we're looking at. Are the scores on the top or bottom as its installed in the car? If I had to guess I would think at the top because that's where the load is carried...and due to gravity the lubrication would flow away from this area to the bottom.

[einreb]

Originally posted by widebody911
Is there a better lube that can be used?

Thats a good question. I used the valvoline moly stuff that chuck uses.

I've heard of some sort of 'monkey snot' stuff that people use on polygraphite rears that you cant get grease fittings on. I'm guessing 'monkey snot' is not the techincal name for the stuff.

Lubemaster... where art thou?

[MotoSook]

Originally posted by widebody911
Is there a better lube that can be used?

How will a better lube help? metal to metal contact=wear.

Unless you can continually feed lubrication between the contact surfaces, and create enough force to separate the two surfaces....there's nothing you can do. As Bernie commented, the grease grooves do not do an adequate job of lubricating the bushings. We had a long discussion about Bernie's problem on GruppeB.

[safe]

This noice/wear problem with the PolyBronze is totaly new to me.
For almost $600 I would expect something perfect and trouble free.
How many has had this problem?

[CBRacerX]

Mine have been on the rear for 4K miles with no problems. I have not yet "relubed" them, but I used lots of Mobil 1 grease initially. There is a small amount of squeaking, but very minor indeed.

EDIT: The noise I hear is not metal to metal. It is more like a "poly" on metal (and is very subduded) - a bit like I used to have in spaded with poly only bushings.

[Breeang]

Bump

[Chuck Moreland]

I'll try to address some of the comments/questions.

Low-Friction Mounts solve a design limitation of the 911 suspension. The factory made no provision to ensure alignment of front/rear mounts of the control arms in the vertical plane. If the mounts are out of alignment binding will occurr with any hard compound bushing including delrin, polyurethane and PolyBronze.

Not all cars have the mount mis-alignment issue. Cars with frontal impact damage or pan replacements are sure to have some misalignment. Other cars may have misalignment due to to the ravages of up to 40 years of potholes and potentially poor alignment from the factory.

My recommendation for lubrication is a good moly grease. Give them an occasional shot, use your oil change as a reminder. Assumes you do regular oil changes, please say you do.

There is a large installed population of PolyBronze. The product comes with good installation instructions, and email / phone support is available. Unfortunately the installation process itself is impossible to control for many reasons:

- condition of the mating parts
- other modifications to the vehicle
- dilligence in following instructions
- skill set of the installer

With a wide population of installed product, these variables ensure that some percentage of the installations will have problems. The challenge to myself and other manufacturers is to make products forgiving of errors and easy to install.

I'm not saying that Bernie (einreb) screwed up the installation, but his situation was not typical. He did send the parts in the pic back to me for inspection. Unfortunately the races where damaged upon removal, impeding meaningful diagnosis. Based on what I did see, the product design was adjusted to slightly increase clearance between bearing/race. His replacement parts had the greater clearance and he has had no problems.