long arm fabrication

[deke]

well i've done my homework and a few of you on here have made your own long arm set-up. from what i've researched the arms themselves are pretty easy in themselves. the crossmember is where my concern is. any of you with production crossmemebers or made your own have anything you'd like to tell someone making their own? hints, tips ideas are greatly appriciated

[jeepxjga]

well we are getting ready to put a new xmember on my new rig, pc of 6"x1/2" thick plate steel and two pcs of 3x3x1/2" angle. weld the angle to the "frame" and tap and drill the holes for the plate steel, then just drill the holes for teh tranny mount and botl it all up. i'll try and get some pics of my friends longarm setup that we did this on already.

[small pederson]

check out claytons set up

[JeepFreak21]

well i've done my homework and a few of you on here have made your own long arm set-up. from what i've researched the arms themselves are pretty easy in themselves. the crossmember is where my concern is. any of you with production crossmemebers or made your own have anything you'd like to tell someone making their own? hints, tips ideas are greatly appriciated


My crossmember was way easier than the arms. My unibody rails are sleeved with c channel under the doors, so I just used some angle iron and 2x4 box tubing. Drilled the holes in the crossmember for the tranny mounts, and that's it. Here's an unfinished picture.
http://www.xjdb.com/temp/xmember.jpg
Billy

[deke]

is the c channel on the inside of the frame rails themselves? or just inboard on the rails?
any more pictures of it?

[JeepFreak21]

is the c channel on the inside of the frame rails themselves? or just inboard on the rails?
any more pictures of it?

The c channel is cupped around the unibody rails, the angle only attaches to the outside edge of it. I'm not sure I understand what you're asking. I got a battery for my camera... what do you want pictures of?
Billy

[deke]

can i get more pictures looking at the whole setup. some pictures of how the arms attach to the cross member?
if you need to email them, i can pm you my email. thanks

[JeepFreak21]

can i get more pictures looking at the whole setup. some pictures of how the arms attach to the cross member?
if you need to email them, i can pm you my email. thanks


I should be done by this weekend and I'll post plenty of pics.
Billy

[cherokeekid]

you have the specs on the c-channel?

[JeepFreak21]

you have the specs on the c-channel?


It's 4" x 6" x 1/4" box tubing cut into channel with 4" on the bottom and 3" on each side... you can find more specs by searching under my name.
Billy

[cherokeekid]

ohhh, I thought you had found C-channel that was the right spec (I was trying to avoid having to cut the box tube in halfish :dunce:

[JeepFreak21]

ohhh, I thought you had found C-channel that was the right spec (I was trying to avoid having to cut the box tube in halfish :dunce:

It makes it cheaper that way.
Billy

[RCP Phx]

Heres my pics!Still havent finished some mods(other projects these days).
Long arm pics (http://hometown.aol.com/rpayne9421/page2.html)

[AzRick]

Here's mine.
I bought the brackets for the frame end from Rockkrawler. No crossmember needed.
http://community.webshots.com/s/image9/4/50/25/122645025JxyIVj_ph.jpg

Rick

[RCP Phx]

Too short to be efffective as a long arm,better off with Goatman's mid-arm setup!

[AzRick]

RCP,

are you referring to mine? If so, I don't understand. Please explain.

Rick

[deke]

so im in autocad drafting my crossmember up. should i make it a bolt on only, or should i make it a combination of bolt on, plug weld and perminiter weld? i know its overkill but looking for the best combination of strength. if i spend another hour welding, so be it.
another question i have is how long does the long arm itself have to be to be effective?

[AzRick]

another question i have is how long does the long arm itself have to be to be effective?

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

[deke]

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 -
http://cherokee.groundclearance.com:81/albums/album09/untitled.sized.jpg

[JeepFreak21]

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


There are no hard trails in the southwest. :laugh:
Billy

[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 -
http://cherokee.groundclearance.com:81/albums/album09/untitled.sized.jpg
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 ;)
http://community.webshots.com/s/image3/7/29/96/114372996FjyaBP_ph.jpg

Here's the pic I posted before:
http://community.webshots.com/s/image9/4/50/25/122645025JxyIVj_ph.jpg

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]

http://cherokee.groundclearance.com:81/albums/album09/65056554RCLbGc_ph.sized.jpg
http://cherokee.groundclearance.com:81/albums/album09/65056586WCGzSG_ph.sized.jpg
http://cherokee.groundclearance.com:81/albums/album09/65056655lWEUbG_ph.sized.jpg

[xtremewlr]

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