Front Suspension R&R with polygraphite bushings ala Souk!

[MotoSook]

Ok..I know it's a black and white topic for most of us here, but I figured I'd share my version of installing polygraphite bushings.

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I made a quick video of how I think the bushings should be fitted....

I think doing it by filing (as some have reported) or some other is a hit or miss install. You might be able to make it work, but...see for your self.

Even a fresh from the factory bushing is not round and with the flex in it, machining it w/o an attachment like I made is not going to result in a round bushing. And without the attachment, you won't take the correct amount off the bushing, because the bushing won't have the same amount of stretch in it as it will when it is installed on the A-arms. Sure the carrier is not exactly round, but with the right fit, you're less likely to bind due to the carriers. Also, machining the material off the OD leaves the smoother finish on the ID for the A-arms to slide on.

The attachment was made to have the same OD of the A-arms. the bushings fit a little tght on it, just like it would be on the A-arm. So when machining, you try to match the ID of the carrier at the ends of the A-arms. I think you get the idea..

Here's the video


Of course polishing the A-arm ends will help too



Not much difference to the eye...but the caliper and the lathe know.....



And the part that we don't want to take for granted:

The foam washer.....

HA! I say screw that! I have a better solution than the factory

ACE Hardware store neoprene washer and a pair of scissors!

I cut it oblong to fit in the cross member. The outer portion is more likely to let water into your A-arm, so the more cover, the better! The neoprene washer is a bout 1/8" thick, fits snug over the t-bar and cut to just fit in the cross member. This should keep water out of the A-arm (and your T-bar safe from the cancer...oxidation!) better than the factory foam piece of crap...

[dd74]

Very interesting, Souk. I've seen so many threads on the Elephant bushings, I wasn't sure anyone considered another type. Why did you pick polygraphite over what Elephant provides? If at all, aren't the Elephants easier to install?

[MotoSook]

David,

I haven't installed Chuck's bushings, so I can't compare the installation process. I haven't driven a car with Chuck's bushings, so I can't compare ride quality.

I can tell you that with the tools I have, the graphite bushings are not difficult to fit. The polygraphite bushings have been around for a while, and they are a low cost solution. I think a lot of the bad reports may have been from less than perfect installation, but who knows....anything can happen, even with the bushings I installed.

I can tell you that I tried to find issues with the bushing use and installation. Yes, I believe a poor installation will lead to binding and later sqeaking of the front suspension.

Do I think the p-g bushings are a good option..yes. Esp. since the suspension is now "new." The owner/driver can compare the new suspension to the old suspension, and it will be like night and day! The car was riding on 35 year old rubber bushings! Heck..anything that is not 35 yrs old will be a huge inprovement. We've seen a lot of folks who rave about the suspension after they've replaced or upgrade (t-bars and shocks)...their 30+ year old suspension parts...do we expect anything else?

I put 22/30 t-bars on this particular car, with Koni adjustables, stock sway bars...I drove the car before I worked on it, and after I worked on it.

The front strut inserts were shot! There was hardly anything left of those old parts. The bushings were shot...

The car felt like it was riding on 3 wheels in certain corners, and it was not corner balanced well (I could visually tell).

So after the bushing, strut insert, t-bars (F and R) (I did not work on the rear shock..they have already been done), new wheel bearings and races, new front rotors, ball joints, turbo tie-rods and caliper rebuild....the CAR WAS A BLAST! I lowered it and corner balanced it..gave a little agressive alignment....(will tweak a little more). I had to deliver the car to the owner, and I was told to "shake it down." So I did...

The car weighed in at 2275...and it hadn't even seen the bastard weight program yet!

So without getting anywhere near the edge, I gave the car a shake down! It was planted! Much better than my car (before it got stripped for the never ending paint job )!

Crisp turn-in, no jarring of the suspension. My delivery route included residential streets, highway and inner city streets...even with 22/30 t-bars, the little car felt great! I adjusted the front Koni's to 180 degrees less than full firm to try and match the 22 fronts....worked very well. The car had very little body roll and on the highway, the front was planted w/o a harsh ride over expansion joints and what is left of last winter's frost heaves.

The rear was a bit loose due to a too soft setting on the shock. I recommended the owner adjust the rear. That should make everything just right.

[Chuck Moreland]

Having installed quite a few sets of these, I guess I can comment. I agree trying to fit these with a file/sandpaper/drum sander/etc or the brute force method is to plan for failure.

The only way to even consider doing this is with a lathe. Whether it is best to machine the OD (which causes an out-of-round ID once pressed into the mount) or the ID (which leaves a coarse friction surface) is a matter for debate.

Since most people don't have a lathe, they are forced to use one of the alternate methods above, with predictable results. In fact it was the difficulty of machining these that prompted the development of PolyBronze, which require no machining.

As a point of comparison, here is a video that shows the free movement of A arms with Polybronze bearings (the torsion bars have been removed). The A arms drop under their own weight with no encouragement except that provided by gravity.

http://elephantracing.com/video/freelymovingAarm.MPG

[450knotOffice]

Souk, I agree with everything you mentioned. It's a little amazing to me that I have gone with 22/28 torsion bars and Bilstein sports along with the new bushings, tie rods, ball joints, strut brace, lowering, corner balance and alignment and the car is now firmer and handles MUCH better yet is much less harsh than it was with the old stock, yet worn out suspension that was originally in there. I was expecting the ride to be a bit harsh but instead I got a better ride because of the new components all around. The car used to crash and shudder over potholes, now it's just a firm bump and that's it.

BTW, while I agree that the PB bushings are state of the art, people like RoninLB have proven that one can get high mileage out of polygraphite if the bushings are trimmed to fit and lubed properly. His car has over 50k miles on the polygraphites according to him.

[island911]

Originally posted by 450knotOffice
. . .
BTW, while I agree that the PB bushings are state of the art, . ..

You agree? . . . with who?

Also; "state of the art" !?

Let's examine that.

The OE bushing solution have proven to last though neglect, abuse, road-grime and DECADES of use.

That is; Just whos replacement bushing can even claim HALF of those four parameters? Do you really think that those PB bushings will seal-out water and grime like the OE? Do you think that they will stand-up to being neglected for a few decades?

Now tell me again, which bushing design is "state of the art"?

I understand; If you want a less expensive part-cost alternative, than OE, you buy Chucks PB.

But then you've also got to concede/acknowlege that those who want an even less expensive part-cost alternative, than PB, ought to be able to go the route Souk just layed out. (. . . keeping in mind that BOTH are in the realm of experimental solutions.)

What is so tough about that/ And, why is it that Souks (or any/all of the others) thread on replacement bushings (not PB) immediately digresses in to "have you seen the polybronze? . .. look . .. its the best"(?)

Really!? I've never heard of these PB's. Maybe someone could tell me more . .. and while they're at it, could someone show me a picture of this guy "Jack Olsens" car . . .I hear its Black, but want to see for myself.

Oh, and Souk, cool 48sx.

[Dixie]

What I hear is perhaps someone with a lathe could do a little business selling refurbished arms with poly bushings. Send your arms in, get a set back...

...And no, I have no idea if the numbers work.

[Elombard]

Would a set of bushings turned down like this fit any car? Or did you do it specifically for that car.

[724doorE]

48SX,

nothing is more amusig at work than to have an unsuspecting person come to my cube and attempt to ues my 48HP only to find "wtf is wrong with this thing!"

I here they don't make em any more finally.........

Back on track,

Souk nice thread and great use of the seal. Thanks,

[MotoSook]

You can always tell which era-of-engineer you are dealing with by the model of HP they carry And yep! I love the reverse polish notation....it eliminates a large percentage of folks from asking if they can borrow my HP....

Back on topic:

I was hoping the thread wouldn't turn into a BP-vs-PG bushing thread, but in the back of my mind I knew it would come up. And this thread was not meant to steer anyone from the PB bushing.

Island is right about the merits of the rubber bushings...they have performed well for a number of reasons. But after 20+ years and with the cost of the OE replacement A-arms (w/ rubber bushings)....it makes sense to find a "better" solution..better is absolutely qualitive with varying degrees for different folks.

I see our cars as "non-general public" cars. The majority of us on this board and other boards, would not be considered the average car owner nor driver. If we wanted stock, we wouldn't have bought 20+ year old cars then begin to customize them.

I don't see the PG bushings as the ultimate solution. Surely nothing last for ever, and it may be that 5 years down the road, the bushings need to be changed. They do wear and they do deform. BUT! They should perform better than the rubber bushings in that they will provide a more "permanant" operation of the suspension...within their useful life...and if I had to replace the bushings in 5 years...I think the $:benefit will still be acceptable. I don't know what the life span of the PG bushings is...I don't think anyone does...for a properly installed set of PG bushings! Most of us and our cars may never see the end of the useful life of such bushings...either through change of ownership or "retirement" of our cars.

SO! I think the PG bushings make sense, but I don't expect everyone to agree....it's like the oil debate. No sense wasting time debating one or the other...they are what they are, and someone looking to install any part, should do a little research so they can make an informed decision. This thread just adds to the data available.

As for machining the bushings for general use...or fitting them to "sent-in" A-arms...I think it would be difficult to do. Not all 911's are created equally. The fit is a custom fit...there are some variabilty in the suspension (carrier and cross bar ID and shape). A person could machine the bushings round, but the chance that the bushing will cause a tight or loose fit makes the idea unfeasible IMO. I prefer a little tight rather than a little loose. The PG bushing will wear-in when it's a little tight...too loose and you might start to feel that jarring from the road...and maybe even changing alingment..I do have a solution that may get us closer to the "one part for all cars" solution, but it needs some refinement.

[724doorE]

Easy, make and inner and outer sleeve for the PG bushings on is stationary and the other rotates with the bushing.... You have a lathe, It'll be easy. Oh wait somebody did that.

Oh wait, thats my point you could do the same thing.....

Maybe I skipped through it, but the key is partially that not everyone is able to afford the PB bushings, or OEM arms. You figure PG is roughly half of PB. Sure if a guy is doing his suspension he will surely spend some money, but will likely have to draw a line somewhere (where and on what components to draw the line is another topic for another discussion) and the PG are clearly a good usable product if installed correctly.

BTW, if anything on the PB's breaks after a few years, my money is on the bronze components getting hammered from the SS sleeves. You better keep that baby greased up good. Plus any grit that gets into the clearance will also cause damage over time.

Having said that, I'd still buy Chuck's product if I had the pocket book to do so. If not, I'd make my own version. 3rd choice will be PG.

And like many others here, due to a loack of money and time, it'll probably be choice three

[MotoSook]

Originally posted by Souk
I do have a solution that may get us closer to the "one part for all cars" solution, but it needs some refinement.

How about a 4th option Dennis?

[JeremyD]

I like it Souk - Plan B

[Wavey]

Has anyone tried using a wheel cylinder hone to fit the PG bushings?

[MotoSook]

Thanks Jeremy..now send me your brakes

Dave,

I considered installing the bushing into the carrier at the front of the t-bar, then boring the bushing round, but that seemed more time consuming and the chance that the bore axis and A-arm axis may not line up made me abandon it. Sure the carrier ears would allow for some misalignment, but there are other reasons why I didn't take that path. I would also have to make a fixture to hold the carrier. All of that made it less attractive to me. I also would rather have a smooth ID on the bushing.

This leads to why I wanted a little drag on the a-arm during movement without the t-bar to restrict movement. I left a little more material than necessary to "fill" the carrier so that even though the carrier is not perfectly round, the bushing will form to it. Now if the carrier is damaged or very much out of round, the method is not going to be much help. The bushing squeezes on the A-arm a bit, but the friction coefficient should not be appreciably greater.

With a little drag and over time, the bushing will find it's happy home within the carrier without losing contact with the A-arm. The bushing is "plastic" and it will creep a bit.

All that, and I'd still have to make the attachment to machine the bushing that goes into the cross member...so I just made one tool....

Obviously, the installation I demo'd requires a lathe, and it wouldn't be efficient to do this if one didn't have a lathe in the shop. I don't consider myself a pro...but it's something that a pro at a shop should be able to perform for his/her customer. When I hear of the prices that some folks pay for a suspension R&R, I see the machining and fitting as minor within that cost.

[anthony]

Not having a lathe is the biggest obstacle to us DIYers not being able to install these correctly. I will probably go with PB because of the relative ease of installation.

[89911]

I would argue the most important part of fitment is the internal dimensions of the bushings. As long as the external diameter fits the housings (either front or rear) with no binding or deformation (changing the interior dimensions), these can simply be glued in place with a suitable adhesive. This way your not relying on the snugness for retentions. The second time I did these, I realized all the fitment for the outside diameter in not as critical, since the glue will retain it more then adequately.
As for the interior, I used a drill press with a hole saw that was as close to the ID of the bushing as possible. I used a very coarse sandpaper and would sand while constantly rotating the bushing for evenness. This would build up heat. I would cool it in a bucket of cold water and then test fit. Repeat until the bushing slid on the polished a arm ends with no play and no extra force. Once I was satisfied, I glued these into the respective housings, added zirc fitting and cross hatchings for disperse the molylube and test fit these on the car. Once greased the a arm would slowly rotate down with no friction. You can use some fine emory paper for the final sanding of the ID if you like, but I felt the rougher surface was more retentive to the molylube. I've been running these for the past 3 years with no problems, squeaks, or play in the a-arms.

[Todd Simpson]

What glue did you use?

[Shaun @ Tru6]

RE: the longevity issue, all I can add is that the targa has about 25K miles on a F/R set of Chuck's polybronze bearings with no issues. Prolly the best mid-$ upgrade I've done to the car.

I've driven a few cars with plastic bushings and thought they were harsh.

In determining how to upgrade any of the cars, I amortize the cost over expected lifetime, throw in some degree of subjective enjoyment factor and then balance with a penny-wise pound-foolish analysis to yield ultimate value. My experience confirms the original hypothesis, Chuck's bearings are worth saving for.

[89911]

Originally posted by Todsimpson
What glue did you use?

I used a trim-mold adhesive type glue because it was quick drying. If done right, there is nothing penny-wise or foolish about them.