jesse10886

mike i went poly beacuase it lasts longer an holds the akward loads that this style suspension puts on its bushings better than the rubber does i don't want to be redoing this in a year or two i want to rebuild the system it has once an enjoy driving the car for years rubber stretches more and wears out faster

i was not aware that the polly kit is a harder or more uncomfortable ride i figured anything new is gonna need broke in but do the poly kits ride worse than the rubber?

68/70Vette

I had a 69 Coupe that looked mint at the time I bought it. I too was having problems with acceleration and stopping. I had the car wheels aligned several time to no avial. I had a clone L88 engine put in it and on acceleration and also sudden braking, it had a pronounced tendency to get sideways. I took it to Guldstrand Motorsports. Dick Guildstrand took it out on an unused part of the Marina Del Rey freeway, cranked it up in speed and slammed on the brakes. Sure enough it got sideways.

He took it back to his shop and put scales under all four wheels. The scale reading from the rear right wheel was two or three hundred pounds less that the rear left wheel. Verdict: Bent frame. It had been in a rear end collision and the damage had so expertly repaired that there was no obvious evidence of a repair. Knowing of an accident, we were then able to find evidence of the repair.

aafadca

I had a similar problem but with a little rumble/vibration too. After checking, I had a missing shim and also a BAD rear wheel bearing. I fixed both issues and the problem went away. I'm not sure which one was causing the problem (either would do it) but it's been running smooth since the repairs.

81pilot

Here we go again.....

81pilot

The poly is a bit stiffer in areas, but it retains more energy thus giving a tad more feedback from the suspension. But the spring and shocks are easily the biggest deciding factor in whether or not it has a harsh ride. Lateral stability is enhanced with poly due to it having greater lateral rigidity. It is my 100 percent belief based of the properties of Polyeurethane vs rubber that the properties of poly create more of a benefit than they decrease ride quality. Just my 2 cents.

Edit: Mike is right, on the TA front bushings, they have more "twisting" associated with thier movement, poly is stiffer and won't perform as well on those. However, I prefer Poly on sway bars. My last 2 muscle cars had sway bars added, they were not Vettes, but I rebuilt using poly and was quite satisfied. They too have more lateral movement, but that movement can be stiffened without a negative cause and effect for the most part. Rubber will "be there" for decades, but will be long past being anywhere near thier intended stiffness, effectively "lasting" no longer than poly, and in most cases dry and brittle, with no give in any direction thus the catastrophic failure of an old rubber bushing when stressed, it crumbles.

Mike Ward

I think you'll find that the rubber bushings last for many years if not decades. The standard poly bushings are NOT the best choice for 3D loads like the front trailing arm bushings and strut rods. This topic has been thrashed to death countless times.

Harsh ride is a well known side effect.

jesse10886

well i've already rebuilt the front end with the poly and just started the rear so i guess i am stuck wth what i have now but reguardless i will have to have a better ride than what i started with thanks for the opinions and comments i like learning and hearing the critisism even if its harsh so long as it is useful critisism i hate hearing bs like "poly bearings suck!".... ok why do they suck...."becuase they suck" i have heard allot of that crap on other furums which is why i love this one

81pilot

Poly BEARINGS do suck........

Mike Ward

I appreciate your position, especially in situations where the poster won't or can't substantiate their comments one way or the other and you're trying to decide what to do. I used poly on my own car because of posts saying 'they rock' and now regret it. The front bushings contribute to a fairly harsh ride and have the inevitable squeaks. The rear bushings, because of their hardness, either cause the suspension to bind or distort from their original shape. This latter part defeats the whole purpose of using a rigid material.

At the time I did not understand the true function of a captured rubber bushing and why OEMs themselves don't buy into the 'poly is better' story.

Each to his own.

BTW- when I removed the original 20+ year old bushings with 105,000 miles on them, they were still in good shape.

81pilot

I disagree with your assertion that the squeak is inevitable. I put on 40K on my 70 Torino GT after I installed poly(actually had it done), and never got a squeak. I even had some on my 72 Ford Pickup it didn't squeak either(rare for a Ford). I think with the right grease in the right places they do fine. My Vette has no squeaks anywhere, although it has only been about 5K since install. As of right now I only have them on the front, but It is like it is on rails, if I want a plush ride I take the wife's car. They will go on the back, except where you pointed out the cross stress angles such as the front of the TA's. I also would say rubber is fine I am not trying to say otherwise, but at 105000 miles it has nowhere near its original properties, far from it, they are way stiffer when new, just because they are in one piece does not mean they are fine. Realistically rubber deteriorates with time more than mileage, just like a tire does. Poly and rubber each have thier place, I love the tight front end and won't go back unless something changes my mind in the future. (slight disclaimer there) I have gotten where I like your input Mike. Makes me think...

kaiserbud

I am pretty flexible to hear opinions, but I put poly bushings in and if you are clean and grease properly they work great and NO noise. And btw - the harshness is called response or road feel. Otherwise - drive a Caddy.

So............ back to the topic...

kaiserbud

I will RE-check these soon and advise. thanks !

CaseyJones

Mine was doing that with a bad rear shock absorber. Every time I would let off the gas it felt like the rear end was coming around favoring the side with the bad parts. A new set of Bilsteins fixed it. Drives great now.