shackle flip and F150 springs ?

ponykilr

Guest
My F350 has a factory 4" block with the fairly stiff springs and an overload spring above those. I have been thinking about the much better ride my daughter's F150 4x4 has (same year, 96) and I am thinking of swapping some parts.

Here is what I am thinking. Use F150 springs with Sky Offroads 4.5" shackle flip and remove the block. This puts me back where I was height wise with much softer springs, but with LESS potential axle wrap and wheel hop due to no block. It also would be a more natural spring movement with the shackle reversed and not under tension.

I don't tow anything heavy with this truck and would much rather have the better flex and ride the softer springs would allow. It would need a 4-6* shim to point the pinion back down but I see much better ride and no wheel hop with this set up. I could even add air bags to tow later if I need to.

What you think? Am I missing anything?



I am doing a front shackle reversal soon to handle the stiff front end.
 
the factory blocks may have some angle built in to them, i would measure those before deciding on shims. also, maybe try the shackle flip with the existing springs first, to see how much ride improvement that gets you over stock setup.
 
grapehead said:
the factory blocks may have some angle built in to them, i would measure those before deciding on shims. also, maybe try the shackle flip with the existing springs first, to see how much ride improvement that gets you over stock setup.
Click to expand...

X2. Not knowing Fords, are the F150 springs the same length and width as your 350?
 
I used to have an 85 fullsize Bronco. I did the shackle flip using a set of front rear spring hangers at the rear, and beefing up the stock shackles so they could survive in compression. I previously had a big ass 5" lift block back there on top of the stock angled wedge block. I also pulled the third leaf from the spring pack to soften it up since I had removed the back seat, tailgate, and hardtop for weight savings. I think I ended up needing to run a 2" straight block to get it level with the front (6" coils), but the pinion angle was perfect with the straight block due to the rear of the leaf springs being lower and changing the angle of the spring pack at the axle interface. I built a traction bar, and was very happy with the setup.
 
I did a shackle flip. Hated it. It drops the roll axis on the rear axle, increases body roll back there.

Ranger race trucks have typically swapped from a (stock) compression shackle setup to a tension shackle for exactly this reason.

How much air is in your rear tires?
 
shawn said:
I did a shackle flip. Hated it. It drops the roll axis on the rear axle, increases body roll back there.

Ranger race trucks have typically swapped from a (stock) compression shackle setup to a tension shackle for exactly this reason.

How much air is in your rear tires?
Click to expand...

I run 30 in the rear. I also have a factory sway bar back there, so I am not sure if body roll would be an issue.
I have read where people have done the flip and had no mention of body roll.\

I would just swap springs or remove leaves from my pack, but with the 4" block I think wheel hop would be bad. It already will hop a little now if I spin from a stop or a roll (on pavement) and those traction bars people run are ugly, I won't be using them.
 
ponykilr said:
I run 30 in the rear. I also have a factory sway bar back there, so I am not sure if body roll would be an issue.
I have read where people have done the flip and had no mention of body roll.\

I would just swap springs or remove leaves from my pack, but with the 4" block I think wheel hop would be bad. It already will hop a little now if I spin from a stop or a roll (on pavement) and those traction bars people run are ugly, I won't be using them.
Click to expand...

Mine hopped like a rabbit with the tall lift blocks. There was zero hopping after the changes. My Bronco was a trail rig that i drove to and from the trails.
 
I think I will try it. If for some reason it doesnt work out I can switch it to something else.
 
If you can find F450 shackles, they're stamped from 1/4", and won't bend like the stock ones will.
 
Watching this one. I've got a 78 f150 frame and 4 inch lift with a rear add a leaf and have been thinking of ditching the blocks and messing with the shackle. It has the factory blocks in it, lift is from an AAL
 
Sky also has a shackle flip that includes a drop front hanger. This way, no pinion angle changes or wedges needed. It's a 6" kit, so this might account for any droop from the lighter springs. I will measure the arch of the springs on my daughter's truck and my parts truck to compare to the 350. If the arch is less the 6" is the way to go. If it is close, it would lift it too much.

http://www.sky-manufacturing.com/cgi-bin/commerce.cgi?preadd=action&key=FORD-RHFK-006
 
Some pictures of the shackle flip and traction bar on my old Bronco from about 2003-2004. This setup worked MUCH better than the tall lift blocks.

The 5-5.5" lift block that came with the 6" Skyjacker lift kit on top of the wedge block:
awww.supermotors.net_getfile_466795_fullsize_left_side.jpg


awww.supermotors.net_getfile_466794_fullsize_left_side_before_1.jpg




Shackle flip, third leaf removed from pack, and 2" straight block:
awww.supermotors.net_getfile_466793_fullsize_imgp0328.jpg


awww.supermotors.net_getfile_466792_fullsize_imgp0327.jpg


Traction bar:
awww.supermotors.net_getfile_200033_fullsize_imgp0323.jpg


awww.supermotors.net_getfile_200036_fullsize_imgp0326.jpg
 
Did some measuring today. The springs on my F150 parts truck are a 4 leaf pack of 1/4" thick springs. They have 1.25" less arch compared to my F350 springs.
The F350 Springs are a 4 spring pack of 3/8' thick springs and the bottom spring is arched and resting on the others. This spring is flat on the F150 springs and would only come into play if the springs were pretty compressed.

So what does this tell me?

I can use the Sky 6" shackle flip with front hanger to drop the spring down with no pinion angle problems.

I remove the stock 4" block which will pretty much eliminate axle wrap.

With the F150 springs having less arch I will end up 3/4" higher in the rear than I am now. I can live with that.

This will give me a great ride from the rear. I can leave the overload spring assembly (mounted on top and has it's own stops) there or remove it and use bags if I need to tow something heavy, but that isn't what I bought this truck for. With my back trouble this truck simply rides too stiff and I really want to keep it so softer is better.
 
I just remembered. I took a second set of F150 springs apart, cut the eyes off of the main, and used that to double up the main leaf. It helped combat axle wrap after the shackle flip.

I still say it's a bad idea. I would have swapped lift springs into mine, but was too poor.
 
Back
Top