WHY DO WE UPGRADE OUR SUSPENSION

RustyRatRod

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I don't know why you guys have problems with rubber bushings..they last years and years.
If you don't tighten your suspension at ride height you will ruin them because you are keeping the rubber permanently twisted...and then you will be blaming the off shore supply.
Rusty,be careful with rear sway bars.I have read that they are not always a good idea.

I don't plan on using it without a front, plus, I lowered the car in the rear with 1" lowering blocks. It has the XHD +1" and they were a little too high for me. Now it sits just right. But you're right, sometimes, especially with a light car, a bar on the back is overkill. It's gonna get one on the rear, I just need to be careful about the size.
 

BergmanAutoCraft

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I don't know why you guys have problems with rubber bushings..they last years and years.
If you don't tighten your suspension at ride height you will ruin them because you are keeping the rubber permanently twisted...and then you will be blaming the off shore supply.
Rusty,be careful with rear sway bars.I have read that they are not always a good idea.
Most of the time this is true. They are huge variables here from mileage, type of usage and these days which offshore supplier you choose. Back in the day, under regular usage, they didn't last that long, hence my comment, lots of front end shops got pretty rich..
 

BergmanAutoCraft

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Speaking of sway bars, do you have a diagram of how your early A body rear bar mounts to the frame? I see it listed on your site but I cannot envision it.
What you don't see is in the parts package. Basically, its a bolt through the frame with a larger hole on one side for an anti crush tube. This along with a spacer to sandwich a sleeve inside the eye bushing allow the round end rotate under suspension motion.
 

BergmanAutoCraft

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Then, there are alignment guys that do understand, cannot get enough caster and have a customer that won't spend the money to make it happen and blames the alignment guy. Many sides to the same coin. It's not always the alignment guy's fault. There are some cheap bastids out there. Then, after they get done blaming the alignment guy, they spend 3K dollars on an aftermarket suspension and still caint get it right. I've seen it. Right here on this forum.
An alignment is an hourly job like anything else. Unfortunately, shops sometimes don't charge this way.
 

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Peter, I agree with pretty much everything you've said here. I would like to clean up a couple things you said though.

First, the torsion bar thing. This doesn't make sense, and it's easy to explain why pushing the torsion bars all the way forward isn't necessary.

If you assume that the LCA socket can't move on the hex end of the torsion bar, then the torsion bar doesn't need to be bottomed out in the LCA socket to keep the LCA from moving back. If you assume the opposite, that the LCA can in fact move on the hex end of the torsion bar, then the reverse is also true- the torsion bar can move in the socket. Which would also mean it can move in the crossmember anchor, so the torsion bar can't be assumed to be holding the LCA from moving back. Either way, there's no reason to bottom out the torsion bars all the way forward. If they can't move then the LCA can't slide back, and if they can move it doesn't help.

Second, the strut rod thing. Yes, the strut rod is a "brake reaction support" and that is its primary reason for being there. Because they are basically a solid link, especially with an adjustable strut rod, they prevent motion in both directions, both forward and back. So they will keep the LCA from sliding back off the LCA pivot if you have a poly or Delrin bushing, just like the originals kept the LCA from walking back and tearing the rubber bushing at that location.




People have "issues" with the poly bushings because they install and maintain them like they're rubber bushings. They are not. With the OE LCA bushings there are no surfaces that slide on each other, the motion of the suspension is just the flex in the rubber (which is built in binding at the extremes of suspension travel, BTW). So there is no need to lubricate the OE bushings, and no way to do so. With a Poly LCA bushing, the bushing actually rotates on the LCA pivot pin. So you have two surfaces sliding on each other, which requires lubrication. And it requires re-lubrication. That's why people complain about the poly bushings squeaking. Well, if they're squeaking it means you need to lubricate them. And if you don't, they will fail. This is no different than any part that requires lubrication. If your ball joints started squeaking you'd lube them, and if you didn't do that immediately they'd wear rapidly and fail.

The other change from OE is that the poly has less flexibility. That's the improvement, but it also has consequences. Namely, the fit of the bushing on the LCA pivot pin, and into the existing LCA outer bushing shell (depending on which poly bushing you're using) has to be tight. These parts have to be a tight slip fit. If there is any play, the bushings will wear out prematurely. Because people install the bare poly bushings into old outer bushing shells and onto original LCA pivot pins with the inner shells the fit is not always what it needs to be. And guys assume the bushings "just slide in" and it doesn't matter. Well, that fit is very important. If you went to install an OE rubber bushing and the pivot pin was loose in the inner shell you wouldn't install it. Same with a poly bushing. No, it isn't a press fit, but the fit still has to be correct.

If you install the poly bushings correctly- lubricate them and make sure they have the proper fit, they'll outlast rubber every time. I always use greaseable LCA pivot pins with poly bushings. They fit the bushings with a higher accuracy than the OE pins, and you can lubricated the bushings as needed. The small grease hole is negligible for the strength of the pin, and the greaseable pins from Firm Feel are a higher quality than the OE pins were to begin with.

If you use Peter's Delrin bushings (I do, they're awesome), the fit is even MORE important because the Delrin has less give than even the poly. So the pivot pin tolerance must be exact. I tried three different pairs of original pivot pins with mine, none fit correctly and all three pairs of original A-body pivot pins and inner shells had different diameter measurements. That tolerance is critical with harder bushings, they must be a tight slip fit with no play.



The OE rubber bushing quality is abysmal now. There are several threads about them not even fitting into the LCA's or onto the pivot pins. None of them will last like they used to, even with proper care. The quality just isn't there. Here are a couple threads where multiple different members talk about Moog and other brand OE style bushings not fitting.

LCA pivot pin loose in bushing problem

Lca bushing help.

Lower control arm bushing

As for the rear sway bar, that depends entirely on how your car is set up. From the factory the front's were undersprung and the rears were ok, but if you do something like add SS springs out back then the rear end is very stiff and adding a rear sway bar makes that worse. If you upgrade the front suspension and have the proper rate rear leaf springs a rear sway bar can be very beneficial. It's not a matter of "rear sway bars are not a good idea". Like any suspension upgrade you have to consider the whole suspension system, some need rear sway bars, others won't, it depends on set up.

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I don't plan on using it without a front, plus, I lowered the car in the rear with 1" lowering blocks. It has the XHD +1" and they were a little too high for me. Now it sits just right. But you're right, sometimes, especially with a light car, a bar on the back is overkill. It's gonna get one on the rear, I just need to be careful about the size.
 

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I don't plan on using it without a front, plus, I lowered the car in the rear with 1" lowering blocks. It has the XHD +1" and they were a little too high for me. Now it sits just right. But you're right, sometimes, especially with a light car, a bar on the back is overkill. It's gonna get one on the rear, I just need to be careful about the size.

I would venture to guess mopar guys don't need a rear bar. Its very common to have high ride height and/or springs in the rear that are too high rate. The best thing to do is test. If you are lucky enough to be able to drive in a large circle with increasing speed, you will find which end lets go first
 

ir3333

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and the exact same thing happened to me Rusty...i bought my springs from Laura (Espo?) and asked for stock height.I think she second guessed me and sent 1" over which made the car sit too high.
I lowered mine by making new front mounts and drilling the spring hole 1" higher to lower the car.
I believe it was 3 1/2" square stock with 3/16" wall thickness...a perfect fit for our mopar springs.
 

GMachineDartGT

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and the exact same thing happened to me Rusty...i bought my springs from Laura (Espo?) and asked for stock height.I think she second guessed me and sent 1" over which made the car sit too high.
I lowered mine by making new front mounts and drilling the spring hole 1" higher to lower the car.
I believe it was 3 1/2" square stock with 3/16" wall thickness...a perfect fit for our mopar springs.
That worked out to be a good thing. You just did the “geometry correction” that some of the big guys do.
 

RustyRatRod

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and the exact same thing happened to me Rusty...i bought my springs from Laura (Espo?) and asked for stock height.I think she second guessed me and sent 1" over which made the car sit too high.
I lowered mine by making new front mounts and drilling the spring hole 1" higher to lower the car.
I believe it was 3 1/2" square stock with 3/16" wall thickness...a perfect fit for our mopar springs.

I traded for mine with a member here who was gracious enough to see I needed springs. I knew they over the XHD ride height already and tried them. They looked cool, but for practical reasons, I used some 1" blocks and now it sits perfect.
 

RustyRatRod

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I would venture to guess mopar guys don't need a rear bar. Its very common to have high ride height and/or springs in the rear that are too high rate. The best thing to do is test. If you are lucky enough to be able to drive in a large circle with increasing speed, you will find which end lets go first

You may well be correct. At the height I have the car now, it's probably a 50/50 shot. And yeah, I got a real good place to do just that. I'll have to try it out when I get the glass back in it.
 

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So do I! Because I know EXACTLY how much the stock suspension is capable of, so when I spend a lot or a customer does, I make sure they get as much for their money as possible.
I've found some cars where you could get more camber than some others.

I would venture to guess mopar guys don't need a rear bar. Its very common to have high ride height and/or springs in the rear that are too high rate. The best thing to do is test. If you are lucky enough to be able to drive in a large circle with increasing speed, you will find which end lets go first
My 71 340 came with the factory front and rear bars still on it when I bought it in late 86 and with good bushings etc. It was a bit loose but I like them that way. A car that pushes pisses me off lol. My 92 318 reg cab short box Dakota had lots of push in it but a good stab on the loud pedal usually induced way more tail happiness than anyone would care to have. Funny how the same size Dakota with a V6 handles so much better with less weight on the nose....especially with 255-65-15 GY Eagles on 8" wheels. Front bar only.
 
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