[64speed]

My rear springs on my 64 with the quick performance 9 inch do not have spring isolators on them on either end. I just ordered some uppers from Ames but quick performance says the springs just sit on the perch and that’s that. What are you guys with aftermarket rears using to cut down on rear suspension noise? I also think some of my rear is in a bind because I have undue harshness. What is the proper method for rear suspension adjustment?

[TB1]

Originally Posted by 64speed

My rear springs on my 64 with the quick performance 9 inch do not have spring isolators on them on either end. I just ordered some uppers from Ames but quick performance says the springs just sit on the perch and that’s that. What are you guys with aftermarket rears using to cut down on rear suspension noise? I also think some of my rear is in a bind because I have undue harshness. What is the proper method for rear suspension adjustment?

My UMI rear springs only have the worn out factory upper isolators on them and no weird noises. Uppers Are QA1 adjustable and lowers are UMI with a rotojoint on one end smooth quite ride non harsh ride other than the poly body mounts. did you tighten all the rear suspension under load or when the car was elevated?

[64speed]

I think it was tightened in the air but that was 8 years ago I honestly can’t be 100%

[64speed]

My brother says we tightened it in the air so what is the proper method?

[grivera]

Loosen the bushing bolts, tighten at curb height, full weight on suspension

[chrisp]

Originally Posted by 64speed

My brother says we tightened it in the air so what is the proper method?

If that is the case from 8 years ago bushings are trash / replace & do it right.

[chiphead]

I use the rubber isolators on the top of the springs where they meet the frame. All rear suspension bushings got poly grease on the moving faces. I've got the adjustable uppers with the spherical links and boxed lowers. I think all the bushings are poly. All suspension points tightened at ride height. Ford 9" rear and no noises so far.

[HWYSTR455]

Pretty sure you only need to tighten the front at ride height, and only when using OE bushings. Those bushings have 'teeth' on them that grab the frame tabs and provide a certain amount of resistance, hence why when you go to poly, the springs are no longer the proper 'combined' rate.

As I recall the rear control arm bushings don't have 'teeth', and operate properly regardless of if you tighten on ground or in air.

The sleeve in the bushing prevent it from being overtightened/binding. That doesn't account for the inherent binding due to the housing 'ear' bushing/movement of rear through it's range, and why you don't use poly bushing on the 'ears'.

As for rear suspension 'noise', it's usually only a slight 'rattle' when the weight comes of the rear, the springs can move around a little. The shocks actually capture the spring, so crappy shocks or aftermarket springs that are slightly shorter can add to the 'rattle'.

When it's in the air and assembled, grab the spring and try to move it around. If it doesn't move, you don't need the isolator. You can put it in if you want, but it isn't going to help with any 'noise'. But if the rattle when you grab it, you need to look at your shocks or springs, doubt the isolators will really do anything. You could try one at both ends of the spring, but that's just a crutch fix.


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[64speed]

I think to a certain extent it’s just the fact that everything is polyurethane.

[HWYSTR455]

You can lube the bushings, but just so all are clear, what does the 'noise' sound like?

And what brand are the bushings? Energy Suspension ones are impregnated with graphite, or at least used to be.


.

[64speed]

It’s not as much as noise as the suspension is just harsh on potholes and things like that. Almost like it’s binding

[HWYSTR455]

Contrary to popular belief, poly bushings don't increase 'harshness' by even a slight noticeable amount. And, ride 'quality' is more of an subjective opinion than a science.

I would be looking at your shocks if it's a 'harshness' thing. What kind of shocks do you have?


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[64speed]

AC Delco. I also have the frame braces. I’m wondering if it’s them.

[HWYSTR455]

Frame braces won't increase ride harshness.

You just need better shocks. Not sure how good the AC Delco ones are, but since they are for an older model, I doubt they're very good.

Bare minimum Bilstein shocks, and if you want to tune the 'ride' to your liking, a single adjustable shock like Ridetech or other.


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[64speed]

I have the AC DELCO heavy duty suspension shocks it turns out so I am gonna try something different

[HWYSTR455]

Originally Posted by 64speed

I have the AC DELCO heavy duty suspension shocks it turns out so I am gonna try something different

Try the QA1 stocker star ones, that's a considerable step up from the Bilsteins and about the same price.

Once you experience good shocks you will never go back.

..

[64speed]

Ok just a thought. I have the heavy duty wagon springs in the back but the shocks are just regular shocks. Is there a height disparity? What I mean is when the shock returns to ride height could it be maxing out its travel and “slamming”?

[242177P]

Originally Posted by 64speed

undue harshness

Originally Posted by 64speed

heavy duty wagon springs

Spring rates are important.

[HWYSTR455]

Originally Posted by 64speed

Ok just a thought. I have the heavy duty wagon springs in the back but the shocks are just regular shocks. Is there a height disparity? What I mean is when the shock returns to ride height could it be maxing out its travel and “slamming”?

Wait, so you put truck springs on it and you're complaining it rides like a truck?

People who recommend those generic 'wagon' springs are making the 101 mistake, and have a limited understanding of suspensions. And yes, we will probably see a rash of those people commenting how 'they work perfectly for me'.

Now I have to ask what springs you put in the front?

Yes, that definitely can happen, the shock maxing out on extension and 'slamming'. And that can kill a shock in a heartbeat. Shocks are meant to operate optimally in the center 40% of the travel, approximately.

Springs are optimized by the corner weights of a vehicle (and the intended use), shocks 'dampen' the travel (so it's not like a pogo stick).

'Matched', or 'matching' springs front/back are rated for a specific type of use, think Cadillac/truck. There's a bunch in between there.

And this is where I usually comment on tolerances of springs by manufacturers, all the generic 'replacement' spring vendors have tolerances in the 10-15% range or more, many complain about leaning to one side or the other due to that fact. So a 350 lbs rate spring can actually be 50 lbs or more in either direction. And you get opposite ends of the tolerance side to side, and bam, lean.

Due to that fact, all those places that say they use 'factory rates' or 'factory specs' goes right out the window, so don't let those marketing schemes fool you.

Look for a manufacturer that has <5% tolerances, and to my knowledge, there's only a small handful. Certain suspension vendors know this, source their' springs from those <5% shops, giving rates based on experience. And generally, the springs don't cost much more than what you would pay for the crappy springs.

Big give-away when a vendor lists springs as 'lowering springs', generally those places don't use the <5% tolerance springs. Also, going more than say @ 1-1.5" lower reduces the amount of an already limited travel range.



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[64speed]

The springs in the front are UMI 1 inch lowering. My nephew has driven it and says it’s not that harsh. I guess I am used to the 60 year old cars I had that had worn out suspensions and front ends. Now everything on this car is new and polyurethane to boot.