Anybody Make Longer Rear LCA?

Discussion in '80-Series Tech' started by Nay, Feb 19, 2009.

  1. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    With my light rig, I have just a bit of rear driveline vibe with my new lift. I can't drop a fortune on adjustable arms right now, so it's either pull the UCA's and shorten them to rotate pinion down or go longer LCA's. I have Slee's HD LCA's now.

    Does anybody make a ~1/2" longer (or adjustable) heavy duty LCA? Given I am going to go to 37's before too long, pushing the travel slightly to the rear, where any trimming will be easier if needed, is an ideal solution as it will also correct wheelbase shortening from the lift while correcting the pinion angle.

    Thanks.

    Edit: MAF's HD LCA's are on clearance for $279 a pair in case you are interested. That is an awesome price, even though MAF doesn't press in the fawking spherical end joint (so call and make sure they do).
     
  2. Ebag333

    Ebag333

    Messages:
    8,161
    Likes Received:
    33
    Joined:
    Oct 3, 2006
    Location:
    Medford, OR
    Why not weld in a adjuster? Very simple to make adjustable rear lower control arms from the stock 80 ones, or as I've seen done just cut and sleeve to the length you desire.
     
  3. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    I could, but after more thought I don't want adjustables. One of the downsides I was thinking about is those lower arms are basically sliders when you use them hard, which I do. So you don't want any adjusting mechanism getting hosed, or any kind of lip hanging you up You basically need a longer piece of heavy duty DOM.

    My practical goal was if I could buy a new slightly longer set, and sell my Slee's, then I'd probably only be a hundred bucks or so into a bolt on project, rather than spending that money cutting and welding stuff and taking a bunch of time to do it.

    Anybody want to start fabbing up longer LCA's? Using our friend Pythagorus' theory on triangle side lengths, also known as A squared + B squared = C squared, going from a 29" long horizontal arm (side B where A=0 and there is no triangle yet to from side C) to an angled arm due to lift (new side C where A = 4" of lift), to keep the axle positioned to the frame properly, C has to be longer in order to keep the original side B at 29". Therefore, 29 squared plus 4 squared = 857, and the square root of 857 is (rounded for simplicity) 29.25" (I am making up the 29" number, I didn't measure that carefully).

    Net, a 1/4" longer than stock LCA should correct pinion angle on a 4" lift, keep the wheelbase at stock length post lift, allow slight bias stuff to the rear where you have more room to trim for tires over 35", and cost not a dime more than the stock length HD LCA's.

    You'd save a ton of money in avoiding the cost of adjustable UCA's and gain other potential advantages as well (assuming you want that extra rear motion due to tire size - .25" doesn't matter for 35's.

    Common folks, somebody build some and send me the prototypes :grinpimp:
     
  4. Ebag333

    Ebag333

    Messages:
    8,161
    Likes Received:
    33
    Joined:
    Oct 3, 2006
    Location:
    Medford, OR
    Here's how a guy local to me did his (if I recall correctly):

    1) Find a piece of tubing that works. Go buy new stuff if you got the $$$, else hit up the scrap yard if you're cheap like me.

    2) Measure how far back you want to move the tires.

    3) Guesstimate how much longer you need the control arms to be. This will be how far you want it moved back and then some as it's angular (IIRC he went with 1/2" for his J springs, fully armored truck with winch).

    4) Cut the lower rear control arm in half. (Crosswise, not lengthwise!)

    5) Two routes for sleeving it:

    Route A would be to just stab the stubs into the tubing, and weld it to the ends. If the tubing is a nice and snug fit (sledge works good for pounding them in), then it shouldn't go anywhere.

    Route B is to cut the tubing lengthwise. Weld the bottom half to the control arms, doing the full length and the ends. Slap the top half on, and weld that the full length and the ends.

    (Either route go VERY slowly around the ends so you don't melt the bushings.)

    6) Put them back on the truck, and have a :beer:


    If you do it the expensive way (buy new steel, have someone do the work, etc) it shouldn't cost you more than $150ish. If you do it the cheap way, it shouldn't cost you more than the cost of the scrap steel ($0.60 a pound here).

    I had someone cut the tubing on mine for $30. They had a plasma torch setup in a jig to do it very cleanly (think of a table saw). I only welded the bottom half of mine, I did not extend it any as with the OME medium lift the axle isn't pulled forward enough to be really noticeable. It wouldn't effect my rubbing at all, or buy me any extra room. If I had J's or taller, then I'd definitely extend them a bit.

    Cost of welding them on was nothing as a club member did them for me. I did throw a couple bones his way to help with consumables.

    All told I think I had about $60 in it. You could do it for way less than that if you cut the sleeving yourself (or pounded them in).


    Tell you what, send me your RLCA's and I'll make you a "prototype" for $100. You cover shipping. :D
     
    Last edited: Feb 19, 2009
  5. Atoyot1031

    Atoyot1031

    Messages:
    2,122
    Likes Received:
    17
    Joined:
    Nov 16, 2006
    Location:
    Aspen, CO
    Who you calling common?:flipoff2:

    I've got adjustable front arms and they slide just fine. Plus with adjustable, whatever you do in the future allows you the wiggle room to deal with it. My .02.
     
  6. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    Apparently a freudian slip designating all of you as peasants :D

    It does depend on how you adjust, a setup in the middle like you see with the UCAs would not work, but if you put an adjustable on the frame end it would. I won't go any higher in lift with a stock mounted link setup, because I don't want to introduce the suspension geometry issues. Custom mounts for more lift means you care for these issues, so this is a one time fix for a 4" lift that addresses more than just pinion angle.

    The more I think about this the more I want to do the lowers to extend the axle back to stock wheelbase and give more room to the front of the wheel well for larger tires than I want to do anything to the uppers just to correct pinion angle.

    With a 1.75" OD 3/8" wall, I have a 1" ID. I could first hammer in a 1" OD stub in the inner and then sleeve with 2" 1.20 wall OD. With a ~.25" length extension that would be more than strong enough and as pointed out would cost very little. I could do the entire thing myself and then just have it welded. :hmm:

    Anybody else taken a cutting wheel to a $400 set of Slee arms? No going back on that one :D
     
  7. FourBy4Toy

    FourBy4Toy

    Messages:
    239
    Likes Received:
    0
    Joined:
    Jan 29, 2007
    Location:
    Longmont, Colorado
    I had a friend cut and sleeve my uppers, I am in CO too, if you want his contact info, I could forward it to you, he is in Loveland, and reasonable..PM me if interested, where are you located? All I see is CO
     
  8. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    Monument, so pretty far south of you. I have a buddy who can do the welding, appreciate the offer.

    I want to bring up one other point to those following this thread in terms of debates I have seen on not extending the LCA's because the tire will stuff too far to the rear. This "off centering" of stuff is actually already what is happening, but to the front, not the rear. In the pic below with a new 35" tire and 2" bumpstop drop at full stuff you have slightly more room to the rear, and I have significantly trimmed the lower quarters (not in this pic), which is the first contact point. You can't do this to the front easily.

    If you are going up to 37's on 3.5" of lift, then ~.25" extension of the wheelbase to the rear combined with probably .5" to 1" additional bumpstop drop should center the tire in the wheel well pretty accurately at full stuff, and you are erring to the side where you are probably doing trimming anyway.

    I am slowly convincing myself to do this :D, but I need to pull the arms and rotate the pinion down to back to spec (angles aligned) to ensure .25" is the accurate increased length. I am pretty sure that the future 37's are going to fit better this way, and it's a low cost solution that adds even more beef to what are already largely indestructible arms.
    FOR Rear Tire Stuff.jpg
     
  9. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    I just ordered a set of 2' 2" OD .120 wall 1.76 ID DOM pieces for the outside sleeve (old style Slee arms are 1.75" OD) and 1' of 1" OD .25 wall to reinforce the inside where it is cut and separated. That means I'll have half inch wall arms along the entire length and 1" thick for a 6" length where I cut. $60 shipped to me (Metal Depot) plus it will be a few clams to get it welded up.

    Pics to follow in a week or so. :popcorn:
     
  10. YellowJacket

    YellowJacket

    Messages:
    104
    Likes Received:
    1
    Joined:
    Apr 11, 2005
    Location:
    Utah
    (Back from the dead)

    "This has got to be the longest week I have ever had to wait for anything!" :D

    Any updates or pictures Nay?

    BTW, I didn't say thanks for the TrXus info before. I did end up buying them for my 80. Just went with 33" for now though. You were right. I love them and they are surprisingly quiet and smooth, and of course CRAZY sexy!

    I have the OME "J" spring lift with running the 33's. I will go 35's (probably max) in the future. I am thinking about building my own LCAs also. Would you recommend 1/4" longer in length for my setup? Looks like you are running a similar size lift, but with 37's...
     
  11. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    I lengthened mine 3/8", which was perfect to correct the driveline and keep the 37's off the front of the wheel wells. We just sleeved them with 2" .120 wall DOM, along with tube in the middle. They are massive :D

    Didn't take many pics, this shows the new arm sleeved before welding compared to the Slee arm.

    Glad you like the trxus :cheers:
    DSC_0039.jpg
     
  12. landtank

    landtank SILVER Star

    Messages:
    19,455
    Likes Received:
    1,833
    Joined:
    Mar 27, 2003
    Location:
    Groveland MA
    Me and another mudder were just talking about this the other day. Seems like the perfect LCA solution.
     
    Nay likes this.
  13. clownmidget

    clownmidget

    Messages:
    2,430
    Likes Received:
    57
    Joined:
    Jul 2, 2003
    Location:
    Trumansburg, New York
    George Scolaro did this Soooooooooooo long ago - he really was an innovator. Had his friend David Q. make a batch of six or so of heavy duty LCA's that were somewhere between 3/8" to 1/2" longer than stock to solve the pinion angle without dealing with changing the UCA's. I like the sleeving method though, it is as heavy duty as you'll ever need ;)
     
  14. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    It's a no brainer, I've been surprised nobody has put these on the market. For the same exact cost as heavy duty LCA's you can fix pinion angle and wheelbase without spending a dime on your UCA's.

    My 37's would actually rub badly on the front of the wheel well without them - under full articulation downhill I can get a bit of surface rubbing as it is. With 35's you have room to spare in both directions, so you aren't going to cause problems.

    It's really an ideal solution as far as I am concerned.

    I still bet I am on the only person to cut a perfectly good set of Slee Gen I HD arms in half :grinpimp:
     
  15. Bikeman

    Bikeman

    Messages:
    550
    Likes Received:
    6
    Joined:
    Sep 7, 2006
    Location:
    Highlands Ranch, CO, Heart in AZ
    Shame on you! This mod is keeping people from doing their share to keep the economy going by not purchasing Slee's adjustable UCA's!
     
  16. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    New product line! People will pay a premium for these!!! :D
     
  17. akarilo

    akarilo

    Messages:
    2,015
    Likes Received:
    81
    Joined:
    Jan 19, 2006
    Location:
    Tulsa, OK
    Could swear you've ranted and raved about, "my 37's don't rub anywhere".:flipoff2: I could be mistaken though.
     
  18. Nay

    Nay

    Messages:
    4,817
    Likes Received:
    938
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    Just polished a tiny bit of Durabak off the inner lip - never heard or felt it. I wouldn't know if not for the Durabak.

    So maybe I should say they stroke it a little bit at just the right angle from time to time. :flipoff2:
     
  19. sleeoffroad

    sleeoffroad Supporting Vendor

    Messages:
    6,178
    Likes Received:
    1,189
    Joined:
    Mar 27, 2003
    The reason we don't make them longer is that it moves the axle back. Under compression the wheel moves back, and making the rubbing problem in the rear worse. Under droop the tire moves down and away from both contact points. I ran 37" SSR's with our 6" lift on they did not rub on the front of the wheel wel. Not sure why your were rubbing
     
  20. sandcruiser

    sandcruiser

    Messages:
    3,582
    Media:
    19
    Albums:
    1
    Likes Received:
    14
    Joined:
    Sep 29, 2004
    Location:
    San Francisco, CA
    I'm more concerned about the panhard. Even with my relatively mild lift (OME mediums- 850) I can see that the rear looks shifted off-center.

    Wouldn't the same "fix" work? to get the axle straight under the truck again?
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.