Im going to run a wishbone setup on this truck...obviously I have read numerous things here and there and even looked over 1000s of pics of setups. I have a few questions for the gurus.. 1) Does it matter which end of the wishbone attaches to the axle? I have seen both ways, Id think that the forces will be the same, so it shouldnt matter...although Id prefer to have the point of the wishbone on my axle so I can have the axle tubes as locations to mount my cantilever brackets to.. 2) I have also seen one case where the fabricator had the lower bar and the wishbone coming to the same point where they attached to a crossmember....I was baffled by this as it seems to oppose everything I have read regarding link suspension setup and "instant center" having to come to a point near the core support....
JMO, with all the articles I've read the open part of the Y should me mounted to the axel. And for #2 you are correct in that they shouldn't mount to the same point. And instant center doesn't have to be roughly the core support. Mine is at about the fire wall. I have an article I put up in the suspension thread I believe about 4 link setups with really good illustrations.
It doesn't matter which way the wishbone is oriented, or whether the links are connected or separated. They will see the same forces generated in all directions. A four link (separated) will distribute the load across two joints rather than one though. You are right, the setup you saw, while it does work, is less than desirable.
I wanna say the ever elusive "Seth" mounted his wishbone with the point on the axle....and even read the praise he gave the wishbone saying it always kept the axle centered or something along those lines...Wishbone it is. Point on axle.
The wishbone point on the axle will also make the crossmember easier to fabricate, as the structure won't have all the location forces at it's center.
