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2.5" lift: do I need to lower transfer case?

Discussion in 'Early CJ5 and CJ6 Tech' started by Txjake, Sep 12, 2007.

  1. Txjake

    Txjake I wrenched with Sparky

    Any opinions on this? :)
     
  2. sparky

    sparky Sandgroper Staff Member Founder

  3. Mcruff

    Mcruff Earlycj5 Machinist

  4. Txjake

    Txjake I wrenched with Sparky

    OK, that is fairly clear.....R)

    didn't think so, but just checking. powertrain is in now and I s/b putting the tub on this weekend, so i wanted to get done with underbody stuff before I go on.
     
  5. StraightToPlaid

    StraightToPlaid Ludicrous speed!!!!

    I've seen lowered T-cases on newer jeeps (mostly cherokees) but I can't remember ever seeing a lowered one on an older CJ-5.

    Any reason why that is? Does the driveline just accept more lift without issues even at funny angles?
     
  6. jd7

    jd7 Sponsor

  7. sparky

    sparky Sandgroper Staff Member Founder

    Shorter transmission/transfer case, no slip yolk so the rear DS is longer I'd guess.
     
  8. jeep67

    jeep67 Member

    I don't know how your cross member is in relation to the frame rails, but most of the all original jeeps that I have encountered have three 1/4-inch plates between the cross member and the frame. If your jeep doesn't have these spacers, then it may be a good idea to include them. I think that a stock jeep with spacers removed is o.k., a lifted jeep with spacers in-place is o.k., but a lifted jeep with spacers removed could cause problems.
     
  9. AJH

    AJH New Member

    Is it three between the frame and c/m? Mine has two there and two inside the frame rail(if that makes sense). I too am installing a 2.5" lift.
    That's the way it was set up when I took it apart. That's not to say the p/o didn't change it.:rofl:
     
  10. jeep67

    jeep67 Member

    I've seen tree 1/4 spacers all between the cross-member and the frame rail. The spacers lower the transfer case and cross-member about 3/4 of an inch or slightly more. I have seen it this way on several jeeps that appeared to be untouched. However, most of the time, I have seen these spacers completely removed, particularly on jeeps that were obviously not "original". Maybe someone with more experience could chime in on this.
     
  11. Hawk62cj5

    Hawk62cj5 Captain of OldSchool

    Mine has no spacers and 2.5 lift with no problems . When I do my T98 swap Im going to put the spacer in because of the shorter drive shaft and steaper angle.
     
  12. 66cj5

    66cj5 Jeep with no name

    mine were oak 3/8" thick. don't know if it was factory or not. replaced with steel when I swapped in the t14.
     
  13. Warloch

    Warloch Did you say Flattie??? Staff Member

    Best way to decide IF you should have the spacers and/or lower your Tcase is to look at the drive line inputs/angles (Tom Woods site explains how they should line up depending on the type of yoke used). This has as much or more to do with the pinion angle on your axles as the slope on the drive line. You really need to look at your engine angle as well. If you move how the tranny/tcase mounts (up or down) it changes the slope of the engine as it sits in the engine bay.
     
  14. dave74

    dave74 Sponsor

    My 74 has two 1/4" spacers on each side, been that way 13 years since I've owned it no problems with u joints 2.5" lift 1" shackle.
     
  15. weedy

    weedy Member

    It is not required but it does reduce the angle of the drive shaft if you lower it a bit. I lowered mine 1" when I installed a lift and the resulting angle of the drive shaft was drastically reduced.

    Not required but it will extend the life of the U-Joints.
     
  16. AKCJ

    AKCJ Active Member

    When I swapped in the sm420 trans I tried 1" spacers to gain floor clearance but it caused a terrible driveshaft vibration. Took the spacers out and cut the floor more & it's been fine for several years.

    Seems backwards but that's my story and I'm stickin' to it.
     
  17. SRedinger

    SRedinger Member

    This is why when I wanted about 4" lift I put on 2-1/2 lift springs and then lifted the Body a couple of inches. On lifts that get more than 3" on a short wheel based 4x4 drive line angle becomes a big issue-- its an issue that can get you stranded in the out-back if not managed. This is why Tom Wood does such a good business with his special drive shafts. But 2 and 1/2 inches is something you can get by with. But if you lifted you Cj5 four inches and ran a longer tranny (sm420 or longer) you would be in a potential U-joint cramp.


    Now my in my CJ6 and the rear drive shaft is significantly longer than a CJ5(Decreasing the U-Joint angles). I have aways frowned on any kind of Body lift-- but I gained so much clearance for bigger trannies, radiators, Extra gas tanks, Bigger tires, exhaust pipe clearance, Clutch linkage-- air flow for cooling-- and TIRE CHAINS on Large tires---- that I did it anyway. A pure spring lift will increase articulation more however--- but I mostly wanted to run 33s with Tire Chains. This is because of my obcession with driving in 3- five foot foot deep heavy snow. Lockers, 33s and Chains on all fours and you can blaze through grill-hood deep snow! This is another reason I got a CJ6 is because a longer wheel base is advantageous in the snow. This is because I am going to return to rural living situation-- and need to not be completely snow bound between the one mile between my cabin and the pavement. Also there is nothing I love more is pulling later model Toyotas, Rovers, and Hummers out of snow banks with an antique old Chained-up Jeep!
     
    Last edited: Sep 18, 2007
  18. sac13

    sac13 Come oooonnnnn summer....

    If you are strickly going 2.5", then no. If you add say, a 1" body lift or HD shackles (most give you an extra 0.50 - 1.0") then you may start to get some vibrations (I did). I added 1" spacers on the crossmember bolts and everyone is happy and quiet now.....
     
  19. sparky

    sparky Sandgroper Staff Member Founder

    A 1" body lift won't give you vibrations, it won't affect the driveshaft angle like a suspension lift will.