New leafs too high, how much will they settle?

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cawcislo

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My 70 duster had 50 year old slant 6 leafs. The ride height on the back was right where I wanted it. Approx 27.25” measuring through the centre of the axle to the wheel arch. I just swapped new leaf springs and with the new leaf now the car sits at 29” which is way too high for my liking. I know the spring will settle, but how much like 1/2” over the next few months?

what are my options? Will loading the trunk up with 400 lbs and driving it for a while help settle them more or faster, but probably not enough. Is adding a 3/4” or 1” lowering block a good idea? Would a spring shop be able to rearch/bend them for me?
 
They'll settle some over time, I've seen a few guys here use a front hanger that drops em an 1" or so. Wish I could be more detailed. As far as having a spring shop re arch em? I wouldn't go that far...
 
Yeah, when I changed everything out under the back, I left the spring eye bolts and the U bolt nuts loose, set it down with full weight on the suspension bounced it a few times then torqued everything.
 
What springs did you install?

How much they settle depends a lot on the quality of the springs. I have a set of Mopar Performance springs on my Challenger that probably settled and sagged at least an 1” or even 1.5” within 6 months to a year. But the AFCO’s on my Duster probably haven’t even settled a 1/2” in several years.

A 1” block isn’t a big deal either, it’s not going to screw up your geometry enough to worry about and they’re fairly cheap and relatively easy to install. You could even install them now and just remove them later if the the springs do settle out enough for you.
 
Bad Sport said:
Yeah, when I changed everything out under the back, I left the spring eye bolts and the U bolt nuts loose, set it down with full weight on the suspension bounced it a few times then torqued everything.
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Just put all poly bushings in the Duster, did the same. Amazing how some of that American rubber was...
 
I know someone with some Eaton spring that have fallen 2 INCHES in 6 months!

That's just bad quality control. Sad.
 
autoxcuda said:
I know someone with some Eaton spring that have fallen 2 INCHES in 6 months!

That's just bad quality control. Sad.
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Good grief! And Eaton is supposed to be a good one.

Like I wasn’t surprised when my Mexico made MP’s did that, and I was actually happy about it because they were too high when I installed them. But damn.
 
Along the same lines as making the final torque with weight on the tires, the u bolt nuts only torque to 45 LB FT. Going tighter will clamp the leafs together too tightly and make them bind, instead of allowing them to slip as the suspension flexes.
 
They are Mopar performance made in Mexico springs. Sounds like they’re gonna settle a lot, which is good. I’ll,loosen everything up just to be sure and bounce it around and see if that makes any difference. I’ll report back tomorrow
 
I installed ESPO's and they might have settled a inch or less in 10 years. I can't remember if I tightened everything down or up.
 
I installed ESPO 1" extra arch about 15 years ago on my 67 273 Dart. It always sat a little higher that I was hoping. I just carry everything but the kitchen sink with me. I have about 15,000 miles and they are just starting to settle a little bit. I would recommend ESPO to anybody looking for new springs.
 
The big problem with the Mexico springs are.....WHEN will they stop settling AND since the spring is obviously compromised, how LONG will they last and what RATE are they now? Because you know all that has changed from their original specs.
 
RustyRatRod said:
The big problem with the Mexico springs are.....WHEN will they stop settling AND since the spring is obviously compromised, how LONG will they last and what RATE are they now? Because you know all that has changed from their original specs.
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The rate doesn’t change, same as torsion bars, same as any spring steel. The spring will sag and the height will change, but not the rate.
 
72bluNblu said:
Good grief! And Eaton is supposed to be a good one.

Like I wasn’t surprised when my Mexico made MP’s did that, and I was actually happy about it because they were too high when I installed them. But damn.
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There's a dry erase board in the shop charting the sag per date measured. They've moved the front spring hanger 3 notches down. Waiting for it to stop so can do pinion angle.
 
autoxcuda said:
There's a dry erase board in the shop charting the sag per date measured. They've moved the front spring hanger 3 notches down. Waiting for it to stop so can do pinion angle.
Click to expand...
Good grief. A chart to map spring sag. Now I've heard it all. LOL
 
Flip the front spring brackets to lower it about 1 inch, if they snag over time flip them back to the original location. This requires you to oval out 2 of the mounting holes. If you don't like that option either get lowering brackets or ESPO springs which in my experience do not snag.
 
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