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Discussion Starter · #1 ·
In the process of rebuilding my rear suspension. I decided to replace the tired rear springs. My Spider is a 1971.

I ordered the centerline standard PS414 spring. I went to install the new springs, and lo and behold my cars rear end is far too high.

Centerline specs their springs hood for 1971 onwards. They don’t really know why the car sits so high.

Classic Alfa sells springs for series 2 cars (SU002), and a different spring for cars after 1983 onwards (SU088).

Does anyone have any advice as to the proper springs for my car?

Dylan
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Curious to know the original spring height and the new spring height? Not the car height, the spring height.

I have a '91, S4. I bought a new set about 2 years ago from Classic and they were 1 1/8" or 37mm shorter than the original.

New on left, original on right.
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You had the weight fully on the rear axle/wheels when you tightened down the trailing arm bolts, correct? If not I could see it turning out like that!

Assuming that's not the issue, what I've run into on these cars is that there weren't really any "standard" springs. The lengths and rates varied a lot depending on body type and series. So with the one-size-fits-all springs that are sold now there's usually a bit of tweaking involved.

The rear springs should have an aluminum shim cup at the top, you can use different thicknesses there to adjust the height. For the rears the shim:height change ratio is about 1:1.

Alternatively, you can also cut coils off the new springs, that will also change ride height about 1:1. I'd suggest to err on the side of less removal first, you can always cut more but kinda hard to add metal back.
 

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Discussion Starter · #5 ·
I will admit I accidentally tightened it all down in the air and then lowered it! I immediately noticed the error of my ways, jacked it back up and loosened all the bolts and lowered it again. I even tried jumping in the rear of the trunk a bit to get the suspension to "settle" to the right height. No beans.

What you see here is with everything loose.

I wish I knew the old spring dimensions...I threw them into the garbage when I took them out...silly me...
 

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Seems weird that there were no shims, I thought those were always present? Part (1) on the diagram.

You aren't using gas charged shocks (Bilstein or KYB) are you?
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Discussion Starter · #8 ·
No shims up there that I could remove. They may just be stuck up there after decades of being under pressure from the spring. Tough to crane my neck all the way in there, but from my phone's flashlight no aluminum spacer.

Shocks are new Koni Reds, which are replacing the original Spica shocks.
 

· But Mad North-Northwest
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Well, that's all really weird, unless the CL springs are way too long. But then I'm sure others would be having the same problem.

You've completely loosened all the trailing arm and sway bar end bolts? Heh, maybe loosen them a bit more? Did you do any other work at the same time, like anything with the trunnion?
 

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Discussion Starter · #10 ·
Replaced the trailing arms, trailing arm bushings, replace the rear anti-roll bar bushings, springs, and rubber spring tops.

Also replaced the bushings in the trunion to diff rubber bushings. All the bolts are very loose.

What I’m curious about is if there was a change to the springs of the later model spiders vs the early ones…

my conversation with Centerline also hit on the fact that other people would have found a problem with the shocks long before me!

a lot of changes were made with this one, though, so who knows what it could be!

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Did you remove the trunnion bar and replace the left and right end bushings, or just the conical bushings at the differential pivot bolt?
 

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Discussion Starter · #12 ·
I didn’t remove the trunnion. The end bushings are the same. They’re such beefy bushings that I’m going to be of the opinion they’ll outlive me!

I did replace the “shim” bushings on the trunnion by cutting a slit in them and just sliding them in the place the old shims were removed from.
 

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OK, then that takes the trunnion off the list of suspects. I do know that spring height, as Gubi has said, will affect your ride height significantly. I lowered my little Cortina GT decades ago by cutting one loop off the front coils, and fabbing lowering blocks for the rear leaf springs. I also think the new springs should be the same free height as the originals, and I don't get why they're not. Maybe they were in the wrong bin when somebody picked them for shipment, and they are for a Giulia sedan?
 
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You don't mention having changed the shocks, so the originals went back in? Some replace them with gas shocks (commonly KYB brand), which are known to raise the rear somewhere around 5/8"... however yours looks much higher.

When you pressed the stabilizer bar links onto the bar, did you make sure to get them installed at the same angle they came off? Wondering if being off angle could result in this. Maybe pop that lower bolt off each arm and see if the rear drops??
 

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I second the suggestion to remove the sta bar links from the trailing arm to see if the links were installed at a wrong angle to the sta bar. Easy to do for a quick check.
No, the sway bar will just pivot upward in the two bushings, regardless of the down links. Besides, I don't think they will clear the back of the axle if you try to install them backwards.
This is indeed, strange, but I still don't like the height difference in that photo.
 

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No, the sway bar will just pivot upward in the two bushings, regardless of the down links. Besides, I don't think they will clear the back of the axle if you try to install them backwards.
This is indeed, strange, but I still don't like the height difference in that photo.
For a second I wondered if backwards and ruled it out as they wouldn't clear the axle as you said. But what I'm wondering is... let's say the proper angle the links are to be pressed on the bar is 45 degrees, but we're accidently pressed on at 60 degrees, wouldn't the links lift the car. I know they rubber in the bushings can twist some, but that much? You may be right, but for the 2 mins to unbolt them, I would.
 

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No, the bar swings freely in the bushings up on the chassis. In fact, when I fitted poly bushings some years back, I had to tie the bar up in position. Poly on both the down links and the chassis bushings.
 

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I don't think the OP did a free height comparison of the original vs new springs. Is that correct?

As shown in my picture above, the springs I got were NOT the same free height, in fact in my case the spring was shorter.

Couldn't it simply just be that the free spring height on the new springs is taller than the originals?

I don't like the shorter springs and re installed original to get my height back to where I wanted. If you ever measure yours and they are the same as my original springs, I'm open to a trade.

Good luck.

Vin
 
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