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Suspension Bushings

jfb05177jfb05177Member
As I contemplate my rebuild, I wanted to hear some opinions and recommendations on what type of suspension bushings to use or ones to avoid.

Other than for returning to an “original” build, why would one WANT to use the original bonded rubber bushings? While they do provide a nonlinear resistance to arm travel, but must be locked into position at a desired initial suspension setting (normally neutral), I would think the inablity to povide exact positioning would make them undesirable.

As for the free floating bushings, is there one particular Pantera parts vendor that has the most desired kit?

Has anyone just used the pieces offered by the various component manufactures (or just built their own)? Would the required items number be available or the dimensions needed to select or make the components be available. I have not taken mine apart yet to measure and more than likely ship to Builder still assembled.

So far just looking at photos from Google searches, I have not noticed any of the free floating bushings addressing the hard surface for thrust face rotation. It looks like the bushing material is just up against the bracket.

Any recommendations about the desired amount of preload (or freedom) of assembly and other things to ensure during assembly would also be appreciated.

thanks, Joe
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markcharltonmarkcharltonOld enough to know better and still young enough not to care. My '71 Pantera
I'm rather surprised this topic hasn't taken off in the age-old Poly vs Rubber debate. Yet. Big Grin

When I rebuilt the suspension on my stock white '71, I chose to use the stock rubber replacements from Maserati Source. I did so because I wanted to maintain originality, but also because I wanted to retain the rather decent stock Pantera ride quality. The same was true when I replaced the springs and shocks — I maintained the stock values. I am very happy I did because the car is (still) a pleasure to drive long distances and over rougher road surfaces.

My blue '71 Pantera has much stiffer springs and the Poly bushings. It handles like it's on rails, but to be honest, I don't enjoy driving it as much except for short trips. I too lack the balls to drive my Panteras all-out but many do.

So I guess the answer depends on a few factors that relate to how far from stock you want to deviate, and how much you want to drive a track car vs a Grand Touring car.

Good luck with your decision Joe.

Mark
markcharltonmarkcharltonOld enough to know better and still young enough not to care. My '71 Pantera
Joe, Thanks for reminding me. I forgot to mention the noise!

YES, you can add zerk fittings and lube them (poly bushings) when installing, as has been done on many Panteras I know, but somehow they all seem to end up making a lot of squeaking noise. I found it rather embarrassing when I drove my blue car across a lawn (which seems to swallow engine noise) for a high-end car show and it squeaked the entire way. Guess what is on my list of parts to replace on that car? Big Grin

Mark
George PGeorge PAdmin.
I'll stir the pot Smiler

There was a time when poly-urethane bushings were a viable choice, because the OEM rubber bushings were hard to find, and expensive if you were lucky enough to find them. That situation no longer exists, the OEM bushings are now available and reasonably priced.

Here's my hierarchy from best to worst in terms of NVH, ride quality (compliance), handling and maintenance. This is how I advise shoppers.

(1) Spherical rod ends - best - premium
(2) New OEM rubber bushings
(3) Poly-urethane bushings
(4) Old, hardened, OEM rubber bushings - worst

If your Pantera is riding on the OEM bushings, you and your car are being subjected to a lot of harshness, and the vehicles handling is being significantly hampered.

-G
tsolotsoloMember
quote:
Originally posted by OSOFAST:
My car has been set up with a set of delren bushings the previous owner made himself. Good ride quality and with no real harshness, plus they are firmer than the rubber bushings, and they are quiet.
Jeff


Jeff,

I was curious about making Delrin bushings. Does your car have white or black Delrin? Can you post a picutre of them? It would be easy enough to turn them out on the lathe. Could even possibly use the original bushings inner sleeves if they were disassembled carefully.

Steve
Last edited by tsolo
bosswrenchbosswrenchMember
Re making your own: you gotta be careful in redesigning suspension parts. The stock rubber 'bushings' were designed to NOT MOVE AT ALL, so the rubber was bonded to both the inner and outer sleeves. The inner sleeve was purposely made long so its bolt locked it into the mount tabs while the outers were tight press-fits. The action was via rubber deformation or twist, controlled by the rubber's formulation when originally made. Incidently, rubber constantly changes with age so 43-yr-old unmolested cars do not ride the same way they did when new.

Plastic bushings don't work that way- they are far too stiff to twist under load. Instead, they behave as true bushings, and don't need either the inner or outer steel sleeves. It's also not a simple materials-swap to get them to work right, and as you'll find when machining plastics. Plastic's high expansion rates with temp changes means some careful calculations & material selection, or you may find them seizing up when really cold, and sloppy when hot. And they melt when too close to exhausts. Reinforced-plastic-composites are best or cracking under load can occur, too. Material color is irrelevant.
panteradougpanteradougMember
Rubber sure does change. It tends to get harder until it reaches a point that it just fractures or cracks.

The factory bushings are a lot of effort to remove. New bushings are available but you probably will feel them loosing effect at about the 5 year range and will want to change them out again.

The nature of the Pantera suspension does not lend itself well to constant removing of these bushings. You are going to beat up the edges of the knuckles in the control arms.

Polyurethane bushings are not a bad compromise. They are now available graphite impregnated so that reduces the squeaks inherent to that material. They are also made in a way that installation of them is very simple and unstressful on both man and machine.

Many race cars back in the day went to bronze bushings to reduce deflection but the ride can be very harsh with those. So harsh that the suspension itself would sometimes crack from the road shock.

Delrin was and is still used by racers but I just see it as "plastic" and it is not my favorite material to risk my life on.

I went with polyurethane. Dark red ones. I will probably change them out eventually when I get tired of the color! Roll Eyes
jfb05177jfb05177Member
I need to photo my bushings where they have just been settting for 30 years (they were fairly new when last driven) But now the cracking rubber is extruded around the arm sleeve

so far my search for bushings, I have noticed they have been done several ways.

Ive sketched (not to scale) what I've think has been done.
1) Just inserting the two pieces of poly AND using a locknut so that the bolt doesnot clamp down
2) Using a sleeve to allow the bolt to ne tightened byt prevent clamping down on the poly inserts
If I can find, I would think using two flanged sleaves, to allow the bolt to be tighten, but not clamp. with the poly a press fit into the arm

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zr1panterazr1panteraForum Sponsor - SACC Restorations
The bottom left of your diagram is how the poly bushings are done today and work just fine. No need to reinvent the wheel. Even the new OE rubber bushings are available now that work much better than the originals but the poly bushings still work fine and will last forever. I have had them in my car for 9 years, not a single squeak...
panteradougpanteradougMember
quote:
Originally posted by ZR1 Pantera:
The bottom left of your diagram is how the poly bushings are done today and work just fine. No need to reinvent the wheel. Even the new OE rubber bushings are available now that work much better than the originals but the poly bushings still work fine and will last forever. I have had them in my car for 9 years, not a single squeak...


Yup. That's them. installed them in 1986. Still in there.

The difficult part is getting the factory bushings out.

It took a combination of a press and grinder to get them out. Then the control arms needed to be refinished. But they have lasted 27 years and are the same as when they were installed.
jfb05177jfb05177Member
another question;

I have not been able to find any postings that give the outside diameter of new OEM bushings. would anyone happen to have that value available. and if known, how much of a fit is desired with the arm

I though if I stumble across an ID roller burnishing tool I would have it ready when ready to install bushings.
tsolotsoloMember
I bought one bushing to measure so I could make adapters to press them out. The new bushing measures 1.184"OD and the rear A-arm I have measures 1.177"ID. The A-arm does have a coat of paint on it that I guess is good for another 0.001" to 0.003". That means the press is really tight! I don't know if the bushings compress when they are pressed in, but maybe or I don't know how they would fit.

Steve

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panteradougpanteradougMember
Yes they are a tight fit. There is a reason that basically it is easier to cut the old bushing out rather that press it out.
There is so little steel in the arm knuckle to press on I was afraid to deform them and cut the bushings out.
I do not think they were intended to ever replace them.
Mine certainly were not worn out, I just didn't like the durameter of the rubber in them.

I am surprised that you can do it without a press at all. I would think the C clamp would bend before the bushing moved?
I think the paint acts like stud and bearing sealer. When you press the bushing in the heat generated melts it.

Maserati Source has the bushings.
tsolotsoloMember
The "C" clamp is actually the Harbor Freight Ball Joint Service Kit. I made the two adapters, one to receive and one to press. The receiver fits snuggly onto the clamp and holds the A-arm inplace. The press adapter is sized to first press the inner rubber out then the outer sleeve. It's not my design, I found a post either here or on the internet somewhere showing a simular setup. That guy said it worked great so I thought I would give it a go. I haven't tried it yet but maybe later this summer. I planned on using the Polly bushings so I haven't made an adapter to press the OEM style bushings in but that would not be difficult if I decide to do so. Maybe if I find some free time I will make the adapter and press the bushing into the A-arm then test the entire concept by removing it. Now, where did I leave that free time?

Steve

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