which leaf springs to remove?

[hairj]

I have a '70 half cab. 351w, 3 spd manual, 33" bfg, 2 1/2" sl and 1" bl., new pro comp shocks and 11 leaf spring pack. Rear leaf springs ride extremely rough. I put 300# of sand bags over the rear axle for the first 150 miles and hit every bump I could. springs are clearly marked 2.5". Measures from top of housing to bottom of frame 10 1/2". Should be 6" + 2.5 or 8.5", right?
Shackles are stock and oriented the proper way. New bushings, torqued proper and move freely.
Thinking leaf removal is only option now.
My question is how many to remove and which ones counting from top down?
Thank you for any and all suggestions.

 

[DirtDonk]

What brand are they? It actually may not matter, but it’s good to know anyway.
For ours (Wild Horses), and perhaps most I think, removing the third leaf from the top (first long leaf that is not part of the double wrap eye) will typically net you about an inch and a half drop.
As usual though, “your results may vary” applies here.

Removing any or all of the bottom three shortest leaves has potentially varied results as well.
In some cases, you only lose the thickness of the leaf springs in lowered height. While others lose a little bit more.
I’m not really sure what the criteria is, or what creates the inconsistencies, since most of the Broncos in question don’t seem to vary in weight that much.
So here again, your results may vary…

 

[bigmuddy]

I have a '70 half cab. 351w, 3 spd manual, 33" bfg, 2 1/2" sl and 1" bl., new pro comp shocks and 11 leaf spring pack. Rear leaf springs ride extremely rough. I put 300# of sand bags over the rear axle for the first 150 miles and hit every bump I could. springs are clearly marked 2.5". Measures from top of housing to bottom of frame 10 1/2". Should be 6" + 2.5 or 8.5", right?
Shackles are stock and oriented the proper way. New bushings, torqued proper and move freely.
Thinking leaf removal is only option now.
My question is how many to remove and which ones counting from top down?
Thank you for any and all suggestions.

Year ago I bought some that rode rough and had a stink bug effect on stance. Shackles weren't overly tight and everything should have been riding correctly. After many talks with the vendor we were at a loss and he just said drive it and see if they settle down?
I ended up basically running it through some ditches around the house making sure to try to cycle them and get them to stuff a tire into the wheel well as best as possible. Eventually heard a "pow" and gone was the stink bug look and they have worked great ever since.
My best guess is the paint or a number of components were stuck and not allowing them to flex correctly. Good luck!

 

[hairj]

What brand are they? It actually may not matter, but it’s good to know anyway.
For ours (Wild Horses), and perhaps most I think, removing the third leaf from the top (first long leaf that is not part of the double wrap eye) will typically net you about an inch and a half drop.
As usual though, “your results may vary” applies here.

Removing any or all of the bottom three shortest leaves has potentially varied results as well.
In some cases, you only lose the thickness of the leaf springs in lowered height. While others lose a little bit more.
I’m not really sure what the criteria is, or what creates the inconsistencies, since most of the Broncos in question don’t seem to vary in weight that much.
So here again, your results may vary…

The springs come from Toms. I will remove the third leaf for sure, and maybe a shorter one. Trail and error I guess. Thanks DD for the info.

 

[hairj]

Year ago I bought some that rode rough and had a stink bug effect on stance. Shackles weren't overly tight and everything should have been riding correctly. After many talks with the vendor we were at a loss and he just said drive it and see if they settle down?
I ended up basically running it through some ditches around the house making sure to try to cycle them and get them to stuff a tire into the wheel well as best as possible. Eventually heard a "pow" and gone was the stink bug look and they have worked great ever since.
My best guess is the paint or a number of components were stuck and not allowing them to flex correctly. Good luck!

Thanks bigmuddy. I will definitely hit some ditches! Thanks for sharing your experience.

 

[DirtDonk]

Yeah, you already started with one of the right steps, which was to add weight to the back.
But you might consider putting the weight back in, slightly loosening all the attaching bolts, then hitting all those bumps and ditches!

Leave the main U-bolts tight, of course, but slightly loosen the two spring eye bolts and the shackle bolts.

And when you say the shackles are on correctly, with factory shackles, that means the open end is facing the rear. Correct?

And you mounted the springs with the double eye to the front spring hanger. Also correct?
Just checking the basics here.

 

[ntsqd]

ROT: the shortest leaves are the stiffest. I always start there. They'll have the least influence on ride height, but the most influence on spring rate at ride height.

 

[hairj]

Yeah, you already started with one of the right steps, which was to add weight to the back.
But you might consider putting the weight back in, slightly loosening all the attaching bolts, then hitting all those bumps and ditches!

Leave the main U-bolts tight, of course, but slightly loosen the two spring eye bolts and the shackle bolts.

And when you say the shackles are on correctly, with factory shackles, that means the open end is facing the rear. Correct?

And you mounted the springs with the double eye to the front spring hanger. Also correct?
Just checking the basics here.

Yes shackle open end is facing rear and spring double eye is to the front. Loosening the attaching bolts sounds like a good idea. Thanks

 

[hairj]

ROT: the shortest leaves are the stiffest. I always start there. They'll have the least influence on ride height, but the most influence on spring rate at ride height.

Sure short springs will only lower ride height the actual thickness of the spring. but MOST influence on spring rate? Did not realize that! Thanks

 

[ntsqd]

They're short and the same thickness (usually) as the other leaves. They're the stiffest leaves in any pack other than likely the over-loads.