Moving shackle hangers, making shackles, question about castor

[josh86k10]

I will be moving my front shackle hangers forward tomorrow (just like on 52" swap, but still with my 6" stock length springs) and will make my shackles the appropriate length to set my castor correctly. I figured I'd put the truck on a lift, leave the front of the spring hooked up, let the rear of the spring float (tires on), lay an angle finder on the knuckle (D60), find the optimum castor angle, measure hole-to-hole, and make my shackles from that. (Wow, what a run-on sentence ).

One problem... what is the optimum castor angle?

I will also be intalling some zero-rates and moving the axle 1.5" forward, so I'll have roughly 7" of lift and the axle 1.5" forward. Basically I need to balance pinion angle and castor angle. What's a good "happy medium" for the castor? 6 degrees? more? less?

I'm also installing hydraulic assist. I've been battling death wobble, and I know the hyd assist will "cure" it, but I would like to get the castor as good as possible to lessen what the band-aid is covering up. I will also be paying a shop to set the toe before I weld the ram in place. Kingpins are good and shimmed approx 1/8"... the main source of the DW is unbalanced 40" TSLs on recentered hummer wheels (hence the hyd assist).

If necessary to get the alignment right, I will buy one of those Tom Wood's superflex joints to account for flex and less than desireable pinion angle. Hopefully it will not come to that. Rotating the knuckles and/or a fancy-schmancy front driveshaft are not currently in the budget.

Thoughts? Thanks in advance.

 

[tRustyK5]

Stock castEr for a D60 is 8 degrees positive. I shimmed mine back to 6 degrees from 10 which helped my pinion angle a lot and also helped (not cured) my DW issues.

I'm also running unbalanced 39.5" TSL's...

Getting my toe-in back to ~1/4" also helped (not cured)

Really, the shim washers on top of the brand new king pin springs and washers made the biggest difference.

i do have a few more variables to work through, but that's where I'm at right now. Hydro assist is in the near future for my truck too.

Rene

 

[mjnemmer]

dont forget when u let the whieght of the truck down on the springs it will change all the measurements u just got once the springs flatten out

 

[josh86k10]

Yep, it sure will..... dammit. Good point. I guess it'll be trial and error then.

New question: Given my goal above, what would be a good length on the shackle to start my guessing game with? 7.25"? 6"? Somewhere between?

 

[protechk5]

Hey Josh86k10 did you ever go through with this? Im about to do the same exact thing, Im running Tc 6" springs with a zero rate with my axle 1.5" forward with a shim. Im replacing my front shackle hanger with kerts shackle eye hanger. I plan on moving it to try and fix my ugly shackle angle and get a better castor angle and ditch the shim. I think my shackles are 6". How much did you move your hanger? Do you have any pictures or suggestions??? Thanks