long arm fabrication

[cherokeekid]

Just out of curiousity sake, what is the purpose of having the arms attach at the cross member, vs mounting on the frame rails?

Seems like a PITA if you need to remove the cross member

 

[Bender]

Deke,

I think you'll have to angle those long arm mounts outwards quite a bit for them to line up properly with the axle mounts. The stock control arms are angled outward slightly and the axle mount reflects this.

 

[RCP Phx]

Well, according to RCP Phx, 28" arms are too short to be effective. I'm not sure where he gets his information, but it's bogus, IMO. My home built arms are 28", the same as Rockkrawlers. They work great. I've tested them on some of the hardest trails in the Southwest with no problems.

Rick

My point was that you will still end up with some pretty steep angles,and also some pinion/driveshaft change.My arms are the same length and mounted parallel to the driveshaft( zero pinion/yoke movement).Also since you dont have a crossmember(for the mounts) I would question the strength!

 

[RCP Phx]

right now, the effective long arm length is 32.5-33.5 i got a little room it play with. i dont see how 5 inches can make a big differance, but it may - heres the cadd drawing i got so far. following the design in the pictures -

That looks exactly like mine but as mentioned the brackets are splayed out about 14*!

 

[AzRick]

My point was that you will still end up with some pretty steep angles,and also some pinion/driveshaft change.My arms are the same length and mounted parallel to the driveshaft( zero pinion/yoke movement).Also since you dont have a crossmember(for the mounts) I would question the strength!

I've observed my suspension many, many times on the trail and I can tell you that there is almost no pinion change.

Pinion angle changes are not due to the length of the lower arm, but rather where the upper arm is mounted and it's length.

I've wheeled more hardcore trails with my longarms and no crossmember than your XJ will ever see, and I've yet to have a problem. My next XJ that I'm currently building will be the same way.

Rick

 

[JeepFreak21]

...Pinion angle changes are not due to the length of the lower arm, but rather where the upper arm is mounted and it's length.

If you're speaking of a "Y" or RE style long arm... that's just not true.
Lets see some pics of your setup!
Billy

 

[AzRick]

Here's an action pic

Here's the pic I posted before:

It's pretty much exactly like the RE Longarms, I just removed the passenger upper arm. The frame end brackets actually extend all the way underneath the factory trans crossmember. I just can see why I need another crossmember to get hung up on.

When I first built them, I ran it as a 4-link. I did have some castor change when flexing it up, but after removing the 4th link, I get barely any. I know this from watching it flex, and from real world testing. The angle of the yoke to the driveshaft never really changes.

Rick

 

[deke]

 

[xtremewlr]

deke, did you create those drawings? If so, awsome work there! Hope you dont mind if I save them for later reference.