Results 1 to 8 of 8
  1. #1
    Join Date
    Aug 2009
    Location
    Hyrum, Utah
    Posts
    2,031
    Chats
    113

    Default help on a long arm build

    i will be building my own long arms for my jeep when i put my new axles under it. i have a few questions. 1. how long should the arms be? 2.what size of metal and thickness should i use? 3.can i leave my upper links in the same location or do i need to put them on the lower arm like the re long arms? 4.can i use bushings on the body side and joints on the axle. or should i use joints on both?
    please let me know and maybe some pics of some builds. every little bit of info will help. thanks for the infor ahead of time.
    01, Tera Flex 6" long arm kit, jks quick disco's,jks bar pin eliminators, Fox 2.0 shocks I won for 5 bucks, Tom woods Sye with rear drive shaft, Tera flex rear disc brakes, custom front bumper, customer rear bumper, rage roof rack. H4 head lights, k&n intake and cone, black steelies with 285x75x16 retreads, metal gas skid. Finally I have a nice jeep no more pos.
    .,=====o00
    //___l__,\____\,___
    l_--- \___l----[]lllllll[]
    _(o)_)___(o)_)--o-)_

  2. #2
    Join Date
    Sep 2009
    Location
    Chico, CA
    Posts
    29,667
    Chats
    1838

    Default

    Building the arms themselves is the easy part. Deciding where and how you will attach them is the hard part. Also you need to decide what bushings you will use.

    Most manufacturers attach them where the cross member bolts to the frame. If you do that, then you need to decide what is going to happen with your cross member. Is it going to be all one piece, or removable without taking the suspension apart. The next thing you need to decide is how many links you need.

    Pros and Cons

    Radius Arms Pros: Simple to design & build. Cheaper to build.
    Radius Arm Cons: Bushing wear due to binding. Tendency to "fall away" under heavy droop (both sides at the same time).


    3 Link Pros: Pinion change through axle cycle. Less stress on LCAs. No bushing/binding issue. More easily tuned.
    3 Link Cons: Increased cost. Design time is higher if you don't understand the concepts. Space limitations depends on what drivetrain you run.


    Long Lowers/Short Upper Thoughts: Amalagation at best. Better than a Radius Arm setup, but the short uppers exaggerate all the movements of the 3 link setup. The more lift, the harder it is to set it up becuase the UCAs are more aggressively sloped than the lowers leading to weird link placement issues.



    True 4 Link Pros: Most flex. Most axle control. Greatest ability to tune. Eliminates the track bar.
    True 4 Link Cons: Oil pan is in the way. Even more space issues than a 3 link. Takes the most time to design & build if you want to do it right.

    Thanks to Joe from Endless Mountain Fab for this comment.

    People like to use Rod ends. They are in style. However, there are different types of rod ends and should be chosen with care. Some are rebuildable, some not. Stay away from the non rebuildable ones, they will stretch or wear out and start clicking on you. It will drive you nuts. Personally, I like rubber bushings. I used them on both ends of my own and am happy. If you do that, you will have to utilize the screw threads as a rotational device, which many manufacturers do. Do not use rod ends on both ends unless you are building a three link. It will tear your uniframe mounts apart.

  3. #3
    Join Date
    Aug 2009
    Location
    Hyrum, Utah
    Posts
    2,031
    Chats
    113

    Default

    thanks for all the info that will make it alot easier. one more question. can i weld a braket to the frame or should i put it on the tcase cross member?
    01, Tera Flex 6" long arm kit, jks quick disco's,jks bar pin eliminators, Fox 2.0 shocks I won for 5 bucks, Tom woods Sye with rear drive shaft, Tera flex rear disc brakes, custom front bumper, customer rear bumper, rage roof rack. H4 head lights, k&n intake and cone, black steelies with 285x75x16 retreads, metal gas skid. Finally I have a nice jeep no more pos.
    .,=====o00
    //___l__,\____\,___
    l_--- \___l----[]lllllll[]
    _(o)_)___(o)_)--o-)_

  4. #4
    Join Date
    Jun 2009
    Location
    Hillsboro ,Ohio
    Posts
    128
    Chats
    0

    Default

    Great post lot of good info for this newbie.

  5. #5
    Join Date
    Sep 2009
    Location
    Chico, CA
    Posts
    29,667
    Chats
    1838

    Default

    Quote Originally Posted by allwaysxj View Post
    thanks for all the info that will make it alot easier. one more question. can i weld a braket to the frame or should i put it on the tcase cross member?
    Yes you can weld a bracket to the frame. BUT, make sure you make the bracket large so the forces are spread out. That metal is thin. For instance, my own brackets wrap around the front curve where the old ones used to be and go back behind the place where the cross member attaches.

  6. #6
    Join Date
    Sep 2009
    Location
    Kalamazoo, Michigan
    Posts
    104
    Chats
    0

    Default

    Quote Originally Posted by allwaysxj View Post
    1. how long should the arms be?
    You really need to do more research. You can just make arms and bolt them on, but that doesn't mean it will handle good. You need to read more about anti-squad and Roll-axis and learn how to set up a suspension currently, or it could have a TON of body roll and ride like crap. If you have this stuff incorrect for your application, it will cost you alot while offroad. How it climbs/doesn't climb, how it rolls/doesn't on side hills and side loads.

    Quote Originally Posted by allwaysxj View Post
    2.what size of metal and thickness should i use?
    On lower arms, you are going to what at LEAST 5/16" wall tubing. We usually sleeve tubing and get in the nieghborhood of 3/8" wall tubing for lowers.

    Quote Originally Posted by allwaysxj View Post
    3.can i leave my upper links in the same location or do i need to put them on the lower arm like the re long arms?
    You "could", but you shouldn't. They will eliminate any gain you could have from a true long arm. Ride will still remain the same as a short arm, flex will be limited.

    Quote Originally Posted by allwaysxj View Post
    4.can i use bushings on the body side and joints on the axle. or should i use joints on both?
    Not if you want to drive on the street. Well, at first you will be able to drive on the street, but the polly bushings will wear out. You will need to find a very hard urethane (like plastic hard) or hard rubber like the factory stuff.
    JcrOffroad
    info@jcroffroad.com
    269.353.1184

    Like us on Facebook for up to date product updates and specials!
    Follow us on Twitter!

  7. #7
    Join Date
    Aug 2009
    Location
    97838
    Posts
    164
    Chats
    0

    Default

    For the lengths and angles, I suggest finding a "link calculator". They are very helpful. I would put a link to one for you but I'm on my phone
    PR officer for North East Oregon 4Wheelers (NEO 4Wheelers)

    http://www.neo4wheelers.com/

  8. #8
    Join Date
    Sep 2009
    Location
    Chico, CA
    Posts
    29,667
    Chats
    1838

    Default

    For a ball park figure, just go twice the length of the stock arms. Something in the neighborhood of 30 - 32"

Similar Threads

  1. My long arm build
    By alwaysxj in forum Modified
    Replies: 63
    Last Post: 10-22-2014, 08:57 PM
  2. long arm kit (96 xj)
    By suby in forum Wanted! (To buy)
    Replies: 0
    Last Post: 06-22-2010, 08:32 PM
  3. Long Arm or 3 Link what is better?
    By brianwy77 in forum Modified
    Replies: 14
    Last Post: 04-22-2010, 09:56 PM
  4. 6in long arm RC lift
    By rguignard in forum For Sale
    Replies: 7
    Last Post: 03-10-2010, 07:52 PM
  5. long startup
    By chrkjpn in forum OEM/Factory
    Replies: 8
    Last Post: 01-28-2010, 06:09 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •