analyze this

[tree_entz]

regarding hill 4wheeldrive 1" front spring shackels.
"Many front lift springs come with a shim already incorporated into the leaf pack to help with the driveline angle; this can sometimes create an undesireable castor condition (wandering etc), and the shackles may actually improve castor, yet bring the pinion angle back down again."
andIt is typically better to try the shackles without shimming first (if using lift springs with a shim)---Just keep this in mind when fine tuning the castor and driveline angle: If the thick part of the shim is toward the FRONT of the vehicle, these shackles will counteract the shim's effect, if the thick part of the shim is toward the REAR of the vehicle (probably done for castor alignment), then these shackles will exaggerate the shim's effect". /forums/images/graemlins/thinking.gif

ok the principles are pretty straitforward, but a few things I need to know.
-how does castor angle cause wandering?
-I want to run this together with ORD's 1" zero rates;
will that balance things out?
-I have 2degree shims that came with my springs
-what would the actual lift be, all I'm really trying to do is level out my shortbox and get as much flex as possible.
Will this be too much lift then (front too high?).
/forums/images/graemlins/dunno.gif
will the suspension guru's please come out?!

 

[sled_dog]

I doubt your front is 2" lower than your rear but its possible. I;ve seen chevys sag in all kinds of odd ways. You really need more of a 4 degree shim in the front for the 1" shackle lift. As far as how it causes wandering, step back from the computer and use your hands as guides. Hold them up 90 degrees to the floor, now hold them perpendicular to each other. Turn them as your wheels would turn in a corner. See nice easy turn going along the ground. Now angle your hands 45 degrees to the floor, prependicular again, and repeat the "turning" process. Get the idea? The turn wants to well turn into the ground. Actually with a shackle lift it would want to turn away from the ground but either way its not turning properly. I'm not a fan of shackle lifts. If I were you, I'd try a zero rate up front and stay away from the shackle lift. If you already have it and want to run it, switch out that 2 degree shim for a little bit larger one. There is a review of Hill4wd 1" lift shackles in the Product Review section of the main page. Steve no longer runs them though. ORD Zero Rates don't have any angle on them so they won't do anything to help the situation.

 

[sled_dog]

quick picture I found illustrating caster angle.

 

[tree_entz]

Thanks for the input! /forums/images/graemlins/grin.gif
Actually, I already have the zero rates, but found out later that they custom mill correction into them. Too late for me I guess, something just doesn't sit right with me sandwiching 2 objects (shim and block) between the spring and axle......

 

[sled_dog]

definetally agree on that sandwiching thing. A local machine shop could machine an angle on them for you. Always worth a look see. How bored out is that 350 you are running man? seems like its .080 over to me.

 

[tree_entz]

I think I'm missing a math component in my noodle, it should be only like a 355 I think since it's .030 over.
does that make sense?

 

[4xcrazy]

[ QUOTE ]
I think I'm missing a math component in my noodle, it should be only like a 355 I think since it's .030 over.
does that make sense?

[/ QUOTE ]

/forums/images/graemlins/waytogo.gif

 

[sled_dog]

yep. mines a 355 in my K5, its bored .030. I have an .080over block, that would be a 364. Too much bore though, can't see running it in anything.

 

[tree_entz]

http://www.aera.org/tech/cube_calc.html
if you can't hack it- google it

and my teechers alwyas sed I'd need math to git by

 

[4xcrazy]

[ QUOTE ]
http://www.aera.org/tech/cube_calc.html
if you can't hack it- google it

and my teechers alwyas sed I'd need math to git by

[/ QUOTE ]

Are you sure it's not english you need help with? /forums/images/graemlins/dunno.gif /forums/images/graemlins/thinking.gif /forums/images/graemlins/grin.gif

 

[sled_dog]

huked on fonics werked fer me

 

[dremu]

nah nah man its PHONIX git it rite mon

 

[sled_dog]

doh, Ive bean out of skoal fir a yir now, cut me a breek.

 

[77 Mud Buddy]

Back on the topic out of hand... I'm running the Hill4wd extneded shackles up front. To counter the caster effect I bought some "E-zero rates" but had them milled at 4 degree's as the write up here on CK5 stated. To tell you the truth 4 degrees different I didnt notice a problem with out the shim but put the ezero rate in to get a little more lift and correct the caster while I was there, I also set the e-zero rate at 1.5" forward to help out with firewall rub and approach angle. My only problem up front since this mod was a busted center pin, I since put in Ford center pins which are a little thicker. So for what it is worth, that's what I did.

 

[tree_entz]

good, good description/input man /forums/images/graemlins/thumb.gif
uh, were the zero rates only 1" to start with? I'd imagine the 4degree wouldn't leave much left on them?
My whole thing is that I try to do things the first time, so if I put in the zeros, get longer shackles in a month and then decide 'oh not enough correction there' gotta take them out send em back to ORD have em milled weeks down the road I'll get em back (I live in east bumfug so the aint gettin milled here). see what I mean?

 

[77 Mud Buddy]

So they were 1" zero rates before the 4 degree angle milled into them but that only took off a 1/8th inch or so. I'm not worried about an 1/8 inch my self.

As for knowing the exact degree your going to need the first time I dont know. You could try and do some calculations to figure that out but I just took CK5's word that with a 2" longer shackle you need to use about a 4 degree shim to correct for camber. As I said above, I didnt even really notice a problem with out the shim I did it just because it was kind of convienent at the time.