Setting up or tuneing up an I beam axle front end

I started this in another thread & moved it here hoping to gain more info

Please help this out guys read what i have so far if not workable please correct me, add to it or What is the correct way to setup or change a stock I beam for the better?


Setting up or tuning up an I beam axle


A) Installed shackles ideally should sit at about a 45 degree angle

B) Well fitted king pins w/o any decernable slop

C) Shoot for 3- 7 degrees castor the higher the # more effort will be needed to turn the wheels or a larger diameter steering wheel will help. Remember wheel size gossly effects leverage.

This is from Dons Hot Rods
No two cars will be the same as far as toe in (or sometimes toe out), and caster. Some cars like more and some like less, you have to start somewhere and fine tune from there. I start at 5-6 degrees caster and 1/16 toe in, and adjust accordingly. Same goes for tire pressure, I start at 28 lbs front and 26 rear and go from there.

D) Better if the tie rod is behind the axle

E) Install 4-7 spring leafs depending on your engine weight

F) A good quality correctly valved shock, Bilstein is a quality shock

G) Make sure your spring has enough arch allowing it to be compressed & not flaten out.

H) How is the drag link installed in respect to the tie rod

This from need_louvers

On a cross steer set up with the drag link close to parallel to the tie rod is good, if not, a slight incline up to the steering box is the better option. On a side steer unit, it would depend on your suspension (wishbones, four bar, etc.) but say a wishbone install with a Ford box (pitman pointing down) keeping the draglink eye level with the wishbone's frame mount and as close to the frame mount as possible is going to be the best geometry. ( I read that now and it's clear as mud, but I don't know how to state it any different. Your looking for the suspension and steering to move in the same arc.) Kinda stare at a stock Model "A" or '32 for a minute and it becomes obvious what I'm yammering about.

This is from waldo53
The drag link needs to be as level as possible in order to avoid bump steer.



I) What is did you install between your spring leafs allowing them to slide easier

This is from need_louvers
Much prefer teflon sheets 'cause I hate the bumps on the spring leaves... with out the bumps the ****ons have a short life and come out easily. I also use wide tubes of shrink wrap from an electrical supply house to cover springs instead of tape or loose fitting vinyl covers.

J) this is from need_louvers

Not a bad idea, but G.M. made a slightly heavier box called the 525 for mid sized cars like the Monza and such, just a bit bigger than the Vega, but smaller than the full sized box. Pretty sure on the number, definite on the application. As a P.S., several "heavy" '36 - '48 Fords have used Vega boxes for many years trouble free. Truth is they're not much heavier than the donar Vega.

K) GM steering box from 1936 up being a heavier vehicle & vega steering from 1935 down

This is from need_louvers
Not a bad idea, but G.M. made a slightly heavier box called the 525 for mid sized cars like the Monza and such, just a bit bigger than the Vega, but smaller than the full sized box. Pretty sure on the number, definite on the application. As a P.S., several "heavy" '36 - '48 Fords have used Vega boxes for many years trouble free. Truth is they're not much heavier than the donar Vega.

L) How are shock mounts set up correctly would it be for instance at 40 % of its travel with an additional 60% left for the road.

This is from need_louvers
Shock length should ideally be as close to 50% as you can make it. I mentioned Bilstein shocks 'cause they are awsome, and when bought through a reputable distributor like Industrial Ch***is they can be valved to your needs for the same price as off the rack

 

I don't know what type steering your going to run but on a Chevy the drag link needs to be as level as possible in order to avoid bump steer.

Edit: I'm running 3 degrees caster on my dropped axle, pretty close to factory spec (again for a Chevy).

Hope that helps.

 

bump

 

No two cars will be the same as far as toe in (or sometimes toe out), and caster. Some cars like more and some like less, you have to start somewhere and fine tune from there. I start at 5-6 degrees caster and 1/16 toe in, and adjust accordingly. Same goes for tire pressure, I start at 28 lbs front and 26 rear and go from there.

Also, add a SoCal steering stabilizer right off the bat. It will give you a lot of peace of mind and better handling.

Don

 

After all that is done, repeat all steps backwards and replace with a ifs!

 

If IFS is so great why don't Simi trucks have IFS? You know Simi's are only driven a million miles a year and a car maybe 30,000. Point is there is nothing wrong with IFS or straight axles.

 

That, and on a fenderless car IFS looks out of place IMO.

Don