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SM420 Clutch linkage upgrade

Discussion in 'Early CJ5 and CJ6 Tech' started by Rick N., Oct 10, 2008.

  1. Oct 10, 2008
    Rick N.

    Rick N. New Member

    Garden Valley,...
    Joined:
    Dec 29, 2006
    Messages:
    8
    I have a freshly rebuilt SM420 that I'm planning on replacing my worn out T14A with in my '68 CJ. What does the group recommend for clutch linkage set-ups? Should I go with the new dual master cylinder, swing pedals, hyd. slave cylinder route? Or should I use Advance's chain drive upgrade kit for the standard linkage.

    My wheeling is primarily two track exploration, soft river bottoms, occasional rock ledge, and pavement(due to so many off-road closures). No extreme rock crawling planned.

    My concerns are: Swing pedal adaption appears to be a bigger project and I lose a dual chamber master brake cylinder. The chain drive route looks like a one day install but mud and grit could create maintenance
    headaches with the chain & sprocket.

    Thoughts and comments???
     
    Rick N., Oct 10, 2008
    #1
  2. Oct 10, 2008
    bkd

    bkd Moderator Supreme Staff Member 2022 Sponsor

    K-Town Tenn.
    Joined:
    Apr 29, 2007
    Messages:
    3,294
    Rick I've got the AA setup on my 6. It's better than stock BUT....I'll be going to hydro in the near future. Reason 1, clutch pedal is awfully stiff...ok for me but my wife and son would/do struggle w/ it. Reason 2, the linkage can loosen up when your in hard torque scenario's on the trails....I had this happen a bunch on a aug run through the Rubicon.
    My advise? go hydro from the start and don't look back :beer:
    Jim S.
     
    bkd, Oct 10, 2008
    #2
  3. Oct 11, 2008
    jeep67

    jeep67 Member

    Shasta, Ca
    Joined:
    Dec 11, 2006
    Messages:
    205
    Rick,

    I improved the stock clutch by: 1) closing the side to side clearance on the torque tube with washers behind the pivot ball on the frame, 2) welded additional 3/16" flat stock to the ears on the torque tube, 3) installed heim joints and solid all-thread on the linkage going from the clutch pedal to the torque tube (bell crank?) and pack to the clutch fork, and 4) installed a turnbuckle with about 1/2 of play to keep the frame and the transfercase from binding. All of these improvements have left me with a clutch that is very predictable and worry free in most any 4x4 situation.
     
    Last edited: Oct 11, 2008
    jeep67, Oct 11, 2008
    #3
  4. Oct 11, 2008
    1960willyscj5

    1960willyscj5 Well-Known Member

    Mesa, Arizona
    Joined:
    Nov 27, 2006
    Messages:
    2,793
    I used all thread and two clevis pin setups for the clutch pedal to bell crank run.
     
    1960willyscj5, Oct 11, 2008
    #4
  5. Oct 11, 2008
    Dan66cj5

    Dan66cj5 Member

    Oregon
    Joined:
    Feb 20, 2003
    Messages:
    235
    You can go with a hanging pedal hydraulic clutch setup and not have to convert to swinging brake pedal. I did that myself, but did convert to hanging pedal brakes down the road. I lost my heater core by doing the hydraulic clutch upgrade. I did relocate the heater core under the dash behind the glove box.
     
    Dan66cj5, Oct 11, 2008
    #5
  6. Oct 21, 2008
    Rick N.

    Rick N. New Member

    Garden Valley,...
    Joined:
    Dec 29, 2006
    Messages:
    8
    Wow, It's been two weeks since I posted my question. I guess time flies when you're workin' your arse off.

    Thanks for the tips guy's. I've scored most of the swing pedal convesion, now I just need to find some time. Anybody
    got any?

    Thanks .... Rick N.
     
    Rick N., Oct 21, 2008
    #6
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