spacing between suspension mounts

[Gabacho_Baja]

I'm looking to fab my f150 up like this Ranger(shown in photo) using chevy 63" springs.

2 questions.

1) How do I calculate the required distance between mounts on the frame for the springs? Should I simply measure the truck I pull them from at the yard?

2) I feel like I read somewhere that the drive shaft angle @ the u-joint needs to bee within 20 degree angle. Is this correct? I want to make sure I mock up all the stuff on the axle correct.

Thanks dudes.

 

[Tater]

Frame mount widths are going to depend on width of the perches on the axle..... but if you are cutting those off and locating new perches on the axle tubes you can put them where ever they work best on frame, axle and make sure the tires don’t rub the springs at full turn.

I set caster before I worry about driveline angles unless they are super whacky. +6-8 degrees of caster is the window I like. Driveline angles need to be addressed but the caster is more important to a well driving rig.

 

[Gabacho_Baja]

Frame mount widths are going to depend on width of the perches on the axle..... but if you are cutting those off and locating new perches on the axle tubes you can put them where ever they work best on frame, axle and make sure the tires don’t rub the springs at full turn.

I set caster before I worry about driveline angles unless they are super whacky. +6-8 degrees of caster is the window I like. Driveline angles need to be addressed but the caster is more important to a well driving rig.

I'm sorry. I should have specified, Front to back. To be honest, I didn't even think about perches and left to right orientation. However, I'm starting with a stripped housing, so as you said, I can set them where it works.

What should I do about the spacing between the shackles?

noted on the caster.

I need to look ahead to the driveline angle after I mock up and tack in everything before I finish weld, No?

 

[Tater]

I'm sorry. I should have specified, Front to back. To be honest, I didn't even think about perches and left to right orientation. However, I'm starting with a stripped housing, so as you said, I can set them where it works.

What should I do about the spacing between the shackles?

noted on the caster.

I need to look ahead to the driveline angle after I mock up and tack in everything before I finish weld, No?

Which side are you wanting to put the shackle on? I usually grab the dimension from leaf spring bushing of the fixed side to the center pin of the spring and that is where I start. Then depending on which side you want the shackle to be on is going to depend on which side you start your mounts from. I like setting the fixed side first to set wheel base. The distance between the two are all going to depend on vehicle weight and how much the spring bows under flex. I like the shackles to ride 15-20 degrees at ride height. If you set the shackle angle to steep it will ride like shit. If to much of an angle you will loose some travel out of it but also will loose spring rate so it really is a balancing act and hard to give a fixed number.

maybe someone out there can chime in some dimensions with the same springs you have?!

remember that the axle is going to go front to back in it’s travel. I’m up travel the axle will go towards the shackle side and in droop the axle goes away from the shackle.

driveline angles are going to be determined on driveline style. I have always just work with the Pinnion angle that I get Out of setting the caster.

 

[rattle_snake]

I'm looking to fab my f150 up like this Ranger(shown in photo) using chevy 63" springs.

2 questions.

1) How do I calculate the required distance between mounts on the frame for the springs? Should I simply measure the truck I pull them from at the yard?

2) I feel like I read somewhere that the drive shaft angle @ the u-joint needs to bee within 20 degree angle. Is this correct? I want to make sure I mock up all the stuff on the axle correct.

Thanks dudes.

20* at u-joint is likely already bound up and won't work. should be under 12* for single type. can't know from just the driveshaft angle need TC flange and pinion to do the math.

To run a lot of lift like pic you will probably need to cut 'C's and re-clock to get pinion-to-drvieshaft angle = 0* and run double cardan at TC end.