Which rear spring leaves to remove?

[blubuckaroo]

I've got 1 set of National 11 leaf rear springs. It already hard a bit of rake to it, but then I added a 6 degree tapered shim to correct the driveline angle.
Now the rake is quite a bit worse.
I'm thinking of removing a leaf or two from the rear. I hope to lower and soften the rear a bit. I'm also hoping that, with it a bit lower, I'll also be able to eliminate the tapered shim.
Question is, which leaf or leaves should I pull out?

 

[bknbronco]

pull a few of the shortest ones. My leaves sagged and softened up after a few thousand miles and i ended up going from a 10deg shim to a 8deg.

 

[SHX669]

My '68 1/2 cab sat too high in the rear with WHs 11 leaf . I called em and they told me to pull one or two of the LONGEST ones.
Four or five years later as things settled in I reinserted the leaf I removed.

 

[blubuckaroo]

I'm not too concerned about the springs settling much further. They've been on the car for about fifteen years now.

 

[DirtDonk]

If they're like the other leaves of that type, then the lowermost 2 short leaves will only lower you the thickness of the leaves themselves. Roughly 1/4" each.

The third leaf from the top (longest leaf that's not part of the double-wrap eye) will net you from 1" possibly up to 2" of drop and will soften the ride as well.
The amount of drop you'll get from that long leaf is probably not known exactly until you do it. Being that they're Nationals and not newer WH/TBP/Duff/JBG/BCB springs where many have removed, or added individual leaves over the years, there is not as large a list from which to pull information.

And being 15 years old too, that could skew results slightly as well.

Good luck. Definitely add your info when it's done, to add to the list.

Paul

 

[DirtDonk]

Forgot to ask, have you determined exactly how much you want to lower it?
And wait, are those 2" lift springs that you have listed in your signature line? Or are they taller?

If they're only 2" lift springs, then everything regarding the third leaf from the top could vary accordingly. Most of the data are from 3.5" lift springs.
But the lower two should remain consistent no matter what the lift.

Paul

 

[JSBX]

I did this a few months ago. I pulled the bottom two short ones. One a little longer then the other. It dropped my Bronco in the rear just a little over one inch and did soften up the ride. There are several post on this and other members have had good luck with pulling the bottom leaf's and some have had good luck puling others in the pack. But the bottom two are the easiest to pull so try those first.

 

[blubuckaroo]

The Rake wasn't an issue till I put in the six degree shim. That shim was only 1/4" thick but raised the rear about an inch. It really goofed up the hard braking control as well.
Putting in that six degree shim was a big mistake!

 

[DirtDonk]

I needed the shims, but it definitely seemed to lift more than you would expect from just a thin piece of steel. Unfortunately I did not measure before and after.
But it corrected the angles perfectly and got rid of the vibrations, so in that it was successful.

I have a small block too however, so I'm just going to remove some material from the block and add the matching 6° angle into the block instead. Not really ready to cut-n-turn the spring perches, so the block gets it.

Paul

 

[blubuckaroo]

I needed the shims, but it definitely seemed to lift more than you would expect from just a thin piece of steel. Unfortunately I did not measure before and after.
But it corrected the angles perfectly and got rid of the vibrations, so in that it was successful.

I have a small block too however, so I'm just going to remove some material from the block and add the matching 6° angle into the block instead. Not really ready to cut-n-turn the spring perches, so the block gets it.

Paul

Paul, I think your right. The shims will lift more than their thickness because of the geometry involved.
I'm not convinced I needed six degrees to begin with to correct my driveline angle. It was so marginal that having a full or empty main tank would affect the driveline angle.
I'm wondering why most of our vendors only stock a six degree shim? I found only one vendor that has a good selection of the shims in different tapers.

 

[MonsterBIlly]

I have an 11 inch 3.5 inch spring pack from WH. I removed the bottom 3 leads. Got exactly what I wanted. About 1.25 in hes lower in rear. It now sits flat with top off. Slightly lower with hardtop on
.perfect for me

 

[OX1]

If they're like the other leaves of that type, then the lowermost 2 short leaves will only lower you the thickness of the leaves themselves. Roughly 1/4" each.

The third leaf from the top (longest leaf that's not part of the double-wrap eye) will net you from 1" possibly up to 2" of drop and will soften the ride as well.

Good to know. Since my body lift turned out to be 2", vs 1", I had considered dropping susp down to 2.5 vs 3.5. I also have the 11 pack deavers. It also might get me enough caster back I might not have to cut and rotate C's.