rear axle center line and spring sag.

[behemoth]

To find out the rear axle center line is it as simple as measuring the leaf spring eye to the centering pin on the leaf. Then take this measurement to the frame? I do not have an axle under the truck a this time. To find center.

Also when the leafs have sagged they become longer with less arch? the rear shackle then is not straight up and down but leaning to the rear of the truck correct ?

I guess I am looking for the rear axle center line measurement from the front leaf spring mount back.

Any thoughts

 

[br0nc0xrapt0r]

what axle stock eb unit?

 

[behemoth]

It would be an explorer 8.8.

 

[broncnaz]

Not all springs actually have the pin in the exact center. But you are correct when the spring sags it becomes longer. The front hanger/spring eye usually stays the same length unless the springs have a large arch. then they would push the axle to the rear.
Are you looking for the measurement on a EB using a 8.8 axle? It is really up to the spring you are using and where the center pin is.

 

[behemoth]

I have the stock springs, but they are basically flat, that pushes the axle to the rear slightly.

My other truck with the 5.5 lift springs has the center pin in a different location, they are sagging as well pushing the axle back as the shackles are angled to the rear. So I can not use this measurement either. It is probably not a significant amount to even worry about, but with the lowered uncut look I want the rears centered a bit more than what I am seeing now.

 

[broncnaz]

Stock springs are fairly flat from the pin forword at least the ones on my stock 71 are but they could be worn. If you have the springs you want than you may need to move the front hanger or redrill the spring perch to get the axle where you want it.

 

[marcm2030]

You could measure the wheelbase length from the center of the front hub to what would be the center of the axle, I believe it is either 92" or for some reason I remember 92 5/8". Marc