There's a slight rake to the frame and car is set at ride height. At 7* of caster the rod ends sit a full 4" below the bottom of the frame! What am I doing wrong or is it supposed to be like this?
You will have to live with it, raise the mounts up and have less caster, or adjust the wishbone clevises....you choose.
You are measuring at the top of the kingpin right? If so you can pie cut the wishbone near the axle to be able to shorten up your frame mounts. Look how low the stock wishbone is at the rear mounting on a Model A sometime.
Looks to me you are measuring caster at the spring? I can't imagine that is accurate, not to mention those types of gauges ****.
somthing else to consider is measuring your caster with the suspension at ride hight with engine weight on it. if you set your caster without engine weight factored in when you do put whe wieght on it your caster will increase as your suspension compresses.
As stated above, you need to piecut your bones. Worked awsome for me!! You can see in the large photos how it brought the front of the bones down and into position. Initially, my bones looked like yours!
Duh, I forgot about engine weight! Don't know how much of a difference it'll make, it's a turbo'd 4 cyl. Probably about 350-400 lbs. Car's gonna be light! I just finished piecutting my bones to get the perch geometry correct. Hate to do it again. Maybe I'll just leave well enough alone and run it as is. I still have 6" of ground clearance to the bottom of the bone bracket.
So I'd thought I'd give it one more shot before going to bed. Moved the angle finder from the leaf spring to the top of the kingpin and guess what? 13* of caster! Raised the bones up to where the rod ends are 3/4" below the bottom of the rails and now I've got a solid 8* of caster! Like I said before, I'm learning as I go! Thank you John Evans! Also, an honorable mention to Hitchhiker for clarifing my bad choice of a leaf spring measuring point! Once again, the HAMB comes through!!
Cut the wishbone off at the boss on the weld just enough to break the bone off the casting, dont cut through it. Just like you cut a yoke off a driveshaft when shortening. after you get it off mock the bone up where you want it on the frame mark the angle need to fit cut and fit it, I usually tig them back together. Holler if you need pics. Jess
Is it just me or does anyone else think the front spring perch should be part of the mock up process as well? Shouldn't the angle of the perch be set to the caster of the axle so the spring operates properly. You set all the rest of that in stone, then try to fit the perch things could get way different.
Since the crossmember appears to already have been welded in, you set the caster of the axle, which positions the spring to its proper angle, then build the perch to suit. No issues with that.
I would like to add something else, it appears you are building in a garage? The floor will have fall running toward the door, the norm is 1/4" per foot, this is about 1.7 degrees. Also as others have mentioned, the weight of the drivetrain and all the other parts.
Cut slices in the top of the radius rod and bend it up to get away from it looking wonky. Here is the deal it needs the caster to function properly, make it function properly.
Come on, you've gone this far, finish it up and do it like everyone says.. You'll be glad you did....