I need to change the too small shackles the PO had on my 40. They are only about an 1.25" wide. What is the longest shackles I can use without having to go to spacers between the springs and axle? This is only until I can afford to put in some lift springs.
Go as long as you want. Remember you will only achieve approx 1/2 of the lift in the length of the shackle and generally speaking the longer the more stupid and inbred it looks.
Longer shackles will change the angle of the u-joint at the third member and change the caster when used on the front axle.
Good article in Toyota Trails a handful of issues back by Mark Whatley on fabbing your own.
Plenty of new and used lift springs out there in case you wanna fix it right the first time and skip the boottyfab.
I am currently sua and intend to stay this way. My tires are 33.00x12.50x15. They are on 10" rims but I am going to switch to 8"s. I don't like that the PO shackles are only about 1.25-1.5" wide. I don't want to go really tall. Just to clear the tires and correct a rear end squatting condition. Thanks<><
Redbone, we make shackles that are 2" wide by 4.25" or 5.25" long from hole center to hole center. But here's the deal; when we tested different lengths we discovered anything over about 6" long from hole center to hole center really does not give any more lift, it merely pushes the end of the spring closer to the ground.
Thanks for the info. My main question is what is the longest shackle I can run without having to use caster shims in the front end? I have a sua setup. <><
Im sittn stock an just put a pair os 2 1/2'' HD from "specter" all around w/ poly bushings...doesnt look to bad,,check out my pics in my profile,,I havent driven it since I put them on...
I wouldn't recommend any longer shackle in the front than stock. Anything longer is going to decrease caster from the +1 degree stock. Do it right, do springs and be done with it. Unless you like a handful of steering with your truck following pavement lines, crown in the road, tire ruts and darting all over the place. Compound this with untold wear in 8 places for slop in your stock steering, throw in some death wobble....Rock on.
33X12.50's on 10" wheels, no lift and sagging stock springs....been there and doesn't leave to much room for flex let alone almost all normal street driving.
I wouldn't recommend any longer shackle in the front than stock. Anything longer is going to decrease caster from the +1 degree stock. Do it right, do springs and be done with it. Unless you like a handful of steering with your truck following pavement lines, crown in the road, tire ruts and darting all over the place. Compound this with untold wear in 8 places for slop in your stock steering, throw in some death wobble....Rock on.
33X12.50's on 10" wheels, no lift and sagging stock springs....been there and doesn't leave to much room for flex let alone almost all normal street driving.
Longer shackles need caster correction. You can run a 4" lift without longer than stock shackles, but thy will invert on you. SO to fix that, longer shackles are needed and then 4* shims if the center pins move 2"s apart giving you an inch more lift.
longer shackles do NOTHING to change/improve shackle angle. Think about it. They may look more appealing and provide some miniscule amount of lift.
The only way to increase the shackle angle is to
1. remove leaf(s) to decrease the spring rate and hence flatten the spring out or
2. move the shackle hanger inward or toward the axle
3. add weight to the truck
I see your logic, but and here is a big but, some lift springs are not the exact same length as stock springs and almost all "good" or higher quality lift kits come with extended shackles to "improve shackle angle" .
I know there is a change in shackle angle from my 4" springs with stock shackles vs longer shackles. There is a better angle when I have the longer shackles on. Following your point, how can I have two different angles with different lengths from the frame due to shackle centers?
The longer the shackle, the closer you move to a verticle shackle angle. Of course it all depends on the length of the springs from spring eye to spring eye. Older/softer/sagged/flat springs are longer eye-to-eye than they once were.
I have never heard of adding longer shackles in the front and not needing shims to correct the caster, but then again I have only added extended shackles to new lift springs.
It's an optical illusion. Post up pics of short and long shanckles installed on your truck with a magnetic angle finder on each. I am confident in doing this it will prove (assuming other factors = such as those outlined in my previous email) the angle is the same.
Besides some reasonably quick and easy small amount of lift, the only benefit of extended shackles that I can reason is additional travel for lifted springs.
sorry to dig this up, I'm going to be getting 2.5 inch lift springs and i already have brand new downey
1.5" extended shackles. Can I keep my new shackles and be ok as far as caster is concerned or am I going to be darting all over the place on the road?
sorry to dig this up, I'm going to be getting 2.5 inch lift springs and i already have brand new downey
1.5" extended shackles. Can I keep my new shackles and be ok as far as caster is concerned or am I going to be darting all over the place on the road?
CruisinMT, I've got the same set up on my rig and it drives fine, that's with a center arm that has some slop in it. (I have another one I'm going to be putting on soon.) I think a lot of problems come from to wide of a tire. I think if you run a 10.50 wide tire or less you are fine. Here's a pic of my rig now.
sorry to dig this up, I'm going to be getting 2.5 inch lift springs and i already have brand new downey
1.5" extended shackles. Can I keep my new shackles and be ok as far as caster is concerned or am I going to be darting all over the place on the road?
