Hey newbie here,

I just replaced my rear leaves with 63 Chevys, but now my truck rides significantly worse and has almost no flex. I mounted the front hanger 10.5 inches (eye to eye) in front of the stock one. I used a double shackle setup in the rear and kept the stock hangers. As far as I can tell there are three possible causes:

1. I didn't mount the front hanger in the right place. Based on my measurements mounting the hanger 10.5 inches in front would keep the axle in it's original location, and as far as I can tell the axle is. But did I weld the hanger in the wrong place?

2: I didn't get good springs. I got the springs from a junkyard; they are 63" and have 2 leaves plus the overload. I found some leaves with 3 or 4 plus the overload, but I figured less leaves would give a softer ride. I pulled the springs off of a mid 90's truck, but they look fairly new (they aren't very rusted). Did I get bad springs?

3. The Chevy swap is really just a mass prank puled on newbies. All the research I could find said they would "ride like a Cadillac and flex like crazy", but mine are crap. Am I just the latest victim to some sort of mass conspiracy?

I'd really appreciate any ideas or help! My current thought is to ghost ride the truck off a nice cliff.

 

did you check here?
https://www.pirate4x4.com/threads/63...wap-faq.20665/

 

Haha yes, many times, but I haven't found anything for my issue.

 

Travel limited by short shock absorbers??

 

Remove the overload. Will definitely help with ride and flex. You need a lot of weight back there to sag those springs with them in there

 

Describe "rides worse" . Bottoms out? feels overloaded? Body roll? too bouncy?

What does your shackle angle look like? What year truck did you put these on? What did you do for shocks?

Got pictures of your swap? always helps to see whats going on.

 

The double shackle may be the problem?? I put my rear shackle mount directly behind the stock mount and used regular shackles. Fabbed up a set of 6 inch shackles. No overload. You can leave half of it to help with wrap if you want. I ran my first set for 4 or 5 years. Flexed great. My most recent set came of a new 2017. I'm only running 3 leafs. I even bent more lift into them on my HF hydraulic press. Very flexy. I had bad axle wrap this time so I fabbed up an anti wrap bar. I'm using cheap ass Rancho shocks mounted at an angle.

 

Pics are worth a 1,000 words.

 

Hey thanks Wadam! I tried that and that definitely took the edge off. It's still not where I'd like, but that helped.

Thanks everyone for the other replies! I disconnected the shocks to make sure they weren't the issue.

My biggest issue is that I think the springs are too stiff. I can jump up and down on the rear bumper and the truck barely bounces - maybe an inch or two. The truck moved a lot more than that when the old springs were on.

I think I welded the front hangars in the wrong place. I kept the original rear hangers, but the shackle angle is wrong. I think it's supposed to be 45 or 90 degrees.

This is the truck at rest, so I need to move the front hangars closer to the front of the truck right?

 

Hey thanks Wadam! I tried that and that definitely took the edge off. It's still not where I'd like, but that helped.

Thanks everyone for the other replies! I disconnected the shocks to make sure they weren't the issue.

My biggest issue is that I think the springs are too stiff. I can jump up and down on the rear bumper and the truck barely bounces - maybe an inch or two. The truck moved a lot more than that when the old springs were on.

It's an 85 and I got Bilstein 5125s for it, but I got 14" and with the current shackle angle they're too long so I might need to get shorter shocks lol.

I think I welded the front hangars in the wrong place. I kept the original rear hangers, but the shackle angle is wrong. I think it's supposed to be 45 or 90 degrees.

This is the truck at rest, so I need to move the front hangars closer to the front of the truck right?

 

Your shackle setup is the problem. The springs are an arch. As the spring compresses the arch becomes flatter. As the arch becomes flatter the distance between the two mounting eyes becomes longer. That's why there's a shackle, to allow the eye-to-eye distance to change. With your shackle setup, there is no room left for the spring to flatten so the spring can't compress.

You need to lengthen one or both of your shackles, or move the shackle mount back on the frame, to get the shackle angle somewhere between 45 and 90 degrees. Shackle angle only applies to the shackle which is attached to the spring.

 

Oh, that makes sense! Thanks! I'll move the mount as soon as I can.

 

Yep, need to relocate rear spring mount back.

 

Did you end up correcting this? IF you dont want to move the front hanger and shocks and stuff, you could just add a different rear mount and ditch the double shackle.

This took me a few hours to draw up, but im pretty good a photo shop so I enjoy it:

 

Looks kind of phallic and like it's doing something crude to the tire.

 

I haven't yet, I was out with the rona and couldn't go into the welding shop. Hopefully I'll get it done next friday! I'm planning on moving the front mount forward because moving the rear mount back would push the axle farther back than I'd like, but thanks for the suggestion! Haha your photoshop is on point! Thumbs up

 

Moving the rear mount does not change the axle position front to rear.

 

This. moving the front mount will change the spring location, not the rear.

 

well actually it does as the axle travels on a radius but 100% agree not worth mentioning. Just like axle at full droop in not positioned on body at same place as under full weight of vehicle.

I should have better worded my previous post. You need to relocate rear shackle mount. As spring is compressed and decompressed the shackle allows that compression movement as spring de-arches under load thus elongating and shortens as spring goes back to an arch as load in lightened thus shortening distance from eyelet to eyelet.

saw an SAS once that spring was hard mounted front and rear. Rode terribly only suspension was sidewall flex of tires. You’ve created same thing.

you may be able to use a longer shackle link that attaches to spring.

I’m single shackle, think length is 9 inches with shackle mount push 2-4 inches back.