SBC CJ2a with Wrangler springs?

Discussion in 'Flat Fender Tech' started by Flat-out, Sep 30, 2010.

  1. Sep 30, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    I'm just starting the build on my '48 CJ2a/M38 and am trying to decide on how I want to set the suspension up. This Jeep will be running a Small Block and I'd like to keep the lift around 4". I've used YJ springs on similar applications and really like the flex and travel.

    1. How common is the YJ spring swap on flat fenders and what are the pro's and con's of doing it?

    2. Are there any aftermarket kits available to make the swap or is it all self fabrication?

    Thanks in advance!
     
  2. Sep 30, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    Oh yeah forgot.....
    3. Spring over or spring under?

    Thanks.
     
  3. Sep 30, 2010
    Warloch

    Warloch Did you say Flattie??? Staff Member Sponsor

    Falcon, CO
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    You might be able to use some of the kits for the CJ5s, but most I have seen were self fabbed. Also, if you want a simple but just as good option, check out Holbrook.
     
  4. Sep 30, 2010
    duffer

    duffer Rodent Power Sponsor

    Bozeman, MT
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    How big of sbc and how much wheel hop is acceptable? I am SUA and still get some hop. No plans here for SOA.
     
  5. Sep 30, 2010
    Vhunter

    Vhunter Member

    Redding, California
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    I am using a 2x4 tube frame and using 3.5 wrangler springs (SUA), and this thing has plenty of lift. I am somewhat wishing that it was lower, I would not go spring over as it has its problems with the springs on the market now, spring over is not needed. Just my view on it.
     
  6. Sep 30, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    Mild 350 Chev. and .....will be using primarily in the sand dunes so some hop is expected but massive hop and loss of traction not acceptable! :tea:
     
  7. Sep 30, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    Thanks for the input. I've used Wrangler YJ's SPOA on low Horse apps. with great success but am concerned about the higher H.P. and heavier engine either overloading the wrangler springs and/or causing bad wheel hop.
    Does anyone out there have a early CJ with a V8 & wrangler springs?
     
  8. Sep 30, 2010
    bkd

    bkd Moderator Supreme Staff Member Sponsor

    K-Town Tenn.
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    yes.....I have a cj6 with 3 1/2" bds YJ lift springs and a Ford 5.0 H/O
    it was a lot of work but in the end a very rewarding upgrade....smooth on the road and floats over stuff on the trail http://www.earlycj5.com/forums/showthread.php?t=44099&page=39
    there's about 10 pages you'll need to read but here's the part in my build thread that covers it
    Jim
     
  9. Oct 2, 2010
    avmechanic

    avmechanic Gearhead

    Langley B.C. Canada
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    I am building something very close to what you have there. I went with YJ style springs as well. I used a 4 1/2" Rubicon express Kit for a CJ that uses YJ springs. I then bought AMC era CJ spring hangers and mounted the springs to the frame. I am really happy with the setup so far but my one complaint is that it sits pretty high. If I did it again I would maybe order the 2 1/2" Rubicon kit or the 3.5" BBS kit. I definitely wanted some more modern type springs to get a better ride. Hopefully my springs will settle a bit when I get the Jeep completed and wheel it a bit. Check out my build for the details. http://www.earlycj5.com/forums/showthread.php?t=60125 . I think you are on the right track going with the YJ springs. I personally think a quality spring under kit is the way to go. Good luck with the project and keep us posted with a buildup in the buildup and fabrications section.
    Greg
     
  10. Oct 2, 2010
    Bob Greenslade

    Bob Greenslade Member

    Roseville CA
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    When I had my 3A I ran a combination of sprung over stock wrangler springs and rear CJ7's, their the same length, and I cleared 35's with some fender trimming. It's easy to add or remove leaf's until you get the ride you want. If your sprung over you'll need to add some sort of anti wrap device or I guarantee you'll bust a pinion. You'll also need to stretch your frame to maintain at least a 80" wheel base. I'm currently running the same set up on the CJ5 in my signature and am very happy with the results.

    If you were in the Sacramento area I have a 3A frame that's fully boxed and set up for Waggy axles fronts out boarded and stretched a little for Wrangler springs that's for sale
     
    Last edited: Oct 2, 2010
  11. Oct 3, 2010
    Vhunter

    Vhunter Member

    Redding, California
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    There is one more thing I forgot to mention, as I did a shackle reversal I did extend my wheel base to 83 inches.
     
  12. Oct 4, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    Thanks for all the info. guys! Right now I'm finishing up some other projects but should be hitting my Flatty hard by the end of the month. I'll post up as I progress.

    Thanks again!
     
  13. Oct 6, 2010
    svaras

    svaras New Member

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    I´m running SOA with CJ7 rears. I do have a track bar but I´m sick with the wheel hop under heavy pedal at the dunes.
    I lenghted the track bar the more I could but the hop is still there.
    If I go with SUA will my hop disapear ?? any imput will be appreciated.
    Sorry for the hijack, but I think is useful info for you also.

    Rgds

    SV
     
  14. Oct 6, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    Very useful!...This Jeep will be used primarily in the dunes and mudflats. I was leaning toward spring over but the more I read and hear I think spring under may be the way to go.
     
    Last edited: Oct 6, 2010
  15. Oct 6, 2010
    Patrick

    Patrick Super Moderator Staff Member Sponsor

    Los Alamos, NM
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    Even though the common opinion here is that spring under is better?
     
  16. Oct 6, 2010
    Flat-out

    Flat-out Double Agent

    Moses Lake, WA.
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    That's what I said....Spring under, Honest :D

    Damn lesdixia, I mean dyslexia!
     
  17. Oct 6, 2010
    madgician

    madgician New Member

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    spring overs are good all you need do is strap all the leafs together ,or get a anti wrap bar from skyjacker $300 i have done both on my 360 and 304 jeeps and will strap the leafs together on the 302efi ford that is going into my 52 flatte..





    jack
     
  18. Oct 6, 2010
    nickmil

    nickmil Super Moderator Staff Member Sponsor

    Happy Valley, OR
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    Strapping the leaves together limits spring movement which equates to less suspension movement and axle articulation.
    Spring wrap is only one aspect. You also have steering issues to contend with, proper suspension geometry, driveline angle issues to deal with, etc.
    Not saying it can't be done but to do it properly it's much more than strapping the leaves together.
    A long fender Jeep which I'm guessing you have with a 304-and 360 in is much easier to spring over than a flatty due to wheel base length...
     
  19. Oct 7, 2010
    madgician

    madgician New Member

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    Just curious but what does wheelbase got to do with it.
    the other stuff does need to be taken care of like you mentioned . ( that job is not for a newbie.)


    jack
     
  20. Oct 7, 2010
    nickmil

    nickmil Super Moderator Staff Member Sponsor

    Happy Valley, OR
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    A longer wheel base makes for longer drive shafts which minimizes U-joint and drive shaft angle issues. The shorter the wheel base, the more critical the drive shaft and u-joint angles become. Get too long of a powertrain and too short of a wheel base and the angles become too much. At the least you get vibration. At the worst you get binding and breakage. Especially with spring wrap as the springs rebound and the shock loads start breaking things like u-joints, drive shafts, pinion/transfer case yokes, output shafts, differential drive pinion shafts, etc. Seen it plenty of times.
     

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