I'm in the middle of a 1/4 eliptic rear suspension and will be running an off-set rear axle with a double triangle 4 link. I'm a little concerned about the links hitting the driveshaft, and thought this had been discussed before.
anyone know where that thread is? or have any experience with this set-up?

Show me a pic of the four link

:)

Ron

I have no pics as I have no links yet
just springs and an axle
I don't know if there will be any problems, but I'm trying to figure out if the geometry would cause the links to get closer as they drop
I'm going to have the links the about the same length and have the lower links start at the outside of the axle and attach to the center of a crossmember. the upper links will start inside the frame rail and attach at the center of the axle. This will cause the lower links to be slightly longer, but the attachement points will be on the same vertical plane at the frame and probably on the axle as well. I don't want the drive shaft to need a lot of slip, and I understand that the links need to be the same length so that the axle doesnt turn as it drops, but what if the fore and aft distance is the same, but the lower triangle hypotonuse is larger?


ow ow ow!
brain is grinding to a halt!

how about normal leaf springs :)

:flipoff2: :flipoff2: :flipoff2:

Seriously, I am trying to figure out a top mount for an offset 60 so I was wondering what you are coming up with for mounting the top links to the center of the axle.

Sorry I don't know the answer, I was just looking for help. I will search for the thread for ya though, if you can describe the upper link mount you have planned that would help me.

Ron

I am running an eaton, and since it is not a cast center section I will be able to weld directly to it, also I am welding a 1/2 inch think sewercap to the back so my top mount will tie into that as well to help spread the load, but only on one side so there will be some sort of bridge action going on as well
f

fawk

damn cast center is killing me.

Ron

Originally posted by fcfred
I have no pics as I have no links yet
just springs and an axle
I don't know if there will be any problems, but I'm trying to figure out if the geometry would cause the links to get closer as they drop
I'm going to have the links the about the same length and have the lower links start at the outside of the axle and attach to the center of a crossmember. the upper links will start inside the frame rail and attach at the center of the axle. This will cause the lower links to be slightly longer, but the attachement points will be on the same vertical plane at the frame and probably on the axle as well. I don't want the drive shaft to need a lot of slip, and I understand that the links need to be the same length so that the axle doesnt turn as it drops, but what if the fore and aft distance is the same, but the lower triangle hypotonuse is larger?


ow ow ow!
brain is grinding to a halt!

1. The links should stay the same distance apart....the only thing that might come into play would be at "full droop" all your front mounts should be ok...check for clearance
2. Good that you are keeping everthing in a "vertical plane" but if the lower links are longer you might end up with a little "rear steer" on compression.
3. You D-shaft slip should not be a problem unless its a "stock" slip joint.
4. As for the hypotonuse being larger I don't think it be a "major" factor for you.....What kind of travel are you shooting for?

Sounds good fred......get welding......:beer: :beer: ;)

I'll tell you how I set up links...
Get some 3/4" (for 3/4 hiems) black pipe and couplings (plumbing pipe) to use for temporary links, some hiem joints, some threaded rod and nuts that fit the joints, some scrap angle iron or flat stock, and some tie-down straps. Now you can mock-up the whole system as many times as you want until you get it perfect.
The rod-ends should thread into the coupling pretty well , if not, you can tack weld the jamb nut to the pipe, and thread the joints in. Use the tie-downs to hang the axle in place and for cycling, start tacking together some temporary brackets with the scrap steel and the threaded rod. Tack weld some pieces of pipe to the frame for bumpstops, you should be able to try a million different combinations of link placement and length without spending any real money... Try to protect the rod-ends from weld spatter, and don't let the rig fall on you while you are cycling the suspension.
Once you are sure you have it working as well as you like, you can design some nice looking brackets and cut some good tube for the links.