Thread: dropped spindle straight axle

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Space considerations make me want to run a straight axle on the front of the latest project. Will be using 61 Pontiac spindles modified to fit the axle. Modification will put the spindle centerline just below the top of the kingpin boss. Front suspension will be a 3 link with parallel torsion bars and panhard bar. Draglink is the same length as the 3link bars and does swing in the same arc so no bumpsteer. Torsion bars will use a link attachment to the axle so caster has much adjustment but initial at 5dg. Camber at 1 dg positive. Toe to be determined. 195/60-14 fronts and 295/60-16 rears. Fronts will present
15/16" scrub. Steering is 5 turns l-l with a 8" pitman.
After all that I forgot my original question. I'm 63 , cut me some slack.
So what do you think? Did I miss something that is going to jump up and bite me in the*?

I'd like to see a picture. Hard to envision just what you've got done.

try to get one up tomorrow.

Sounds interesting. Is it kind of like a sprint car front? And what steering box are you using to get 5 turns on an 8 inch pitman? I am battling with that issue right now on my car and with a 3 1/2 turn (max) box with an 8 inch pitman I have maybe 1 1/2 turns stop to stop.

Do I know you? I lived by Belle for 20 years down on the Redwater.
Yes, it is a modified sprint front. My original question, which I forgot, was what is the dropped spindle going to do the steering geometry. Is the front end going to want to not return to center, be hard to turn or or any other gremlins that turn up on these kind of modifications?
Using a Corvair box ,unreversed at this point. Am still in the planning and mockup stages. The spindle steering lever is also 8" so a 1-1 ratio. Will probably shorten that up for a faster ratio which will also mean less turns L-L. It will also mean more steering effort which means a larger steering wheel if objectionable and I kinda have my heart set on a 54 Olds wheel with the globe in the center.
You can slow down your ratio by lengthening the arm at the spindle or shortening the pitman.
Measure the length of swing at draglink hole centerline of pitman at your prefered number of turns. Write it down.
Using a square off the backing plate or wheel, turn the spindle to front or rear lock and draw a line on a piece of cardboard fixed to the axle. This line has to intersect the centerline of the kingpin on the end your steering arm is affixed to. Swing spindle to other lock and repeat. Find the point between the two lines that correspondes to the pitman number and draw a straight line between them. Now measure from the kingpin center( where the two lines intersect) to the line you drew between the lines and that will give you the length of the steering arm to the center of the draglink hole for your desired turns L-L

Originally Posted by 61bone

Do I know you? I lived by Belle for 20 years down on the Redwater.
Yes, it is a modified sprint front. My original question, which I forgot, was what is the dropped spindle going to do the steering geometry. Is the front end going to want to not return to center, be hard to turn or or any other gremlins that turn up on these kind of modifications?
Using a Corvair box ,unreversed at this point. Am still in the planning and mockup stages. The spindle steering lever is also 8" so a 1-1 ratio. Will probably shorten that up for a faster ratio which will also mean less turns L-L. It will also mean more steering effort which means a larger steering wheel if objectionable and I kinda have my heart set on a 54 Olds wheel with the globe in the center.
You can slow down your ratio by lengthening the arm at the spindle or shortening the pitman.
Measure the length of swing at draglink hole centerline of pitman at your prefered number of turns. Write it down.
Using a square off the backing plate or wheel, turn the spindle to front or rear lock and draw a line on a piece of cardboard fixed to the axle. This line has to intersect the centerline of the kingpin on the end your steering arm is affixed to. Swing spindle to other lock and repeat. Find the point between the two lines that correspondes to the pitman number and draw a straight line between them. Now measure from the kingpin center( where the two lines intersect) to the line you drew between the lines and that will give you the length of the steering arm to the center of the draglink hole for your desired turns L-L

No, we don't probably know each other, I've not been here long. Thanks for the info on measuring. I have another issue and it was a thread already. I am building cowl steering and in an attempt to get the tierod leveled out I was running into some issues with steering arm length/pitman arm length ratio. I have had to re-engineer to overcome the whole nasty mess and my parts to do that are at the machinist's now.