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Hate to do it, but.... poly or rubber???
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Author:  '74 Sport [ Thu Jun 12, 2003 10:24 pm ]
Post subject:  Hate to do it, but.... poly or rubber???

I know there's been much talk in the past about suspension rebuilds. I read all the past posts from the last two years and still have not come to any conclusion about which might be best - rubber or poly.
Doc, I tried the link you posted to moparts.org, but it looks like they may have removed the thread you referred to discussing this debate. I am in the process of removing the front suspension on my son's '74 Sport to swap in the disc brakes from a donor '73 Swinger. All the seals and bushings will need to be replaced.
From those of you who have been through this before, I would like to hear your opinions. Please be specific about the pros and the cons, the benefits and the pit-falls.
I would also like to find out some good sources for reasonable prices on the parts.

Thanks much,
Jerry

Author:  Matt Cramer [ Fri Jun 13, 2003 7:30 pm ]
Post subject:  I used polyurethane.

When I rebuilt my Dart's front suspension, I used an Energy Suspension Polygraphite kit, about $100 or so from Summit Racing. That doesn't include ball jonts or tie rods, which I bought at AutoZone. I have not noticed any additional harshness with them or any other drawbacks.

Author:  Dan Trump [ Fri Jun 13, 2003 7:57 pm ]
Post subject: 

I have a 74 swinger with a full PST poly kit, 340 torsion bars, and a front sway bar and i wouldn't trade it for anything. My sister had a 74 4 door all stock and that thing went around corners on its door handles. My car rides well on all road-doesn't beat you up any. The bushing will ocasionall squeak very mildly-not loud-only drawback i can find.. This car handles like a much newer car....very tight. I only have 14 inch rallys w/205/70/14 junk tires tires right now too.. can't wait for better tire/wheel combo. A good alignment man can do lots to make it handle also. So spend the money for the poly.. you will not be dissapointed... Have fun

Author:  gtdart [ Sun Jun 15, 2003 9:14 pm ]
Post subject: 

I have read many posts asking this question and have never felt like there has been a complete answer (no offence to anyone intended).

Most folks rebuilding thier suspensions go from old worn out, loose as a goose, wandering around the road cars to tight, well manered, responsive machines. If they used rubber, they swear by it and if they used poly, they swear by poly. I think we all agree that regardless of what you choose, new bushungs (and ball joints etc) will make a huge difference.

I have not read an opinion of someone who went from good rubber to good poly or vise-versa. Because poly tends to slide in its surroundings, it can and usually does squeak a little. I have a set in my 64 el camino and this is the case. I cannot comment on wether they are harsher feeling or transfer more vibration than the rubber since I too pulled old failing rubber out of it.

The reason that I decided to put them into the el camino was curiosity and availability (poly was/is all the rage right?). All in all, I'm happy enough with it poly that I went ahead and bought the full pst poly kit for my 64 dart convertable. Can't yet comment on the ride quality as I am still in paint.

I suspect that torsion bar selection, tire profile and shocks will play a larger part in road harshness and vibration than the bushings but that is more opinion than experience. I'd say, go with the poly, see what you think. If you hate'm, change'm, it's not the that big a deal. This way, you'll have the poly experience and satisfy your curiosity. It's kinda' part of the whole "fixing up an old classic" right? However, if your really concerned about the ride getting to stiff, go with the rubber, they are sure to please.

Author:  kesteb [ Mon Jun 16, 2003 12:57 pm ]
Post subject: 

On my '65 I have a mixture of poly and rubber. The rear springs are all poly, this was a no-brainer. The front suspension is poly on the strut rods and rubber for the UCA and LCA. The reason that I used rubber on the control arms is that the poly replacements do not work the same as the OEM rubber parts and this worried me. The OEM pieces are bonded rubber to the steel inserts. The poly replacements are not. To me, this would allow for movement in those areas. And some people do experience that problem.

Author:  '74 Sport [ Mon Jun 16, 2003 2:34 pm ]
Post subject: 

Is the problem with oil leaks and other contaminants which deterioriate the rubber (and not the poly) as big an issue as I have heard?

Jerry

Author:  Bob D [ Mon Jun 16, 2003 7:28 pm ]
Post subject: 

I agree that a new rebuild with either rubber or poly will feel great. However, I believe that the poly will feel great for many more years than rubber. I don't see why poly shouldn't last almost indefinitely.
Bob D

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