No announcement yet.

Transfer case- possible swap

  • Filter
  • Time
  • Show
Clear All
new posts

  • Transfer case- possible swap

    Hi All-

    Just wondering out loud about a possible t-case swap. On Novak's site, they claim a Dana 18 is a drop in for a QT, no major mods required.

    Anyone on here done this, if so, is Novak telling the truth? I kind of like the idea of not having to do a major diff and driveline swap, seeing the 18 is offset like the QT.

    I got no personal probs with my QT, but if and when it takes a dump, have no desire to use one of those fail-o-matic Chinese drive chains I keep reading about over and over....if anything, I'd retire the QT case before it gets grenaded, in the hopes that someday some good domestic company would kindly make some again. Apparently no one is making domestic chains anymore.

    Second musing, anyone ever put in a passenger side drop NP205? If so, how hard/involved was it? I know the rear diff would have to be a centered one, just wondering if any Wag owners have gone the 205 route.

    Thanks again for listening, and any and all comments are welcome.

  • #2
    The only real major issue when swapping to a different tcase from the Quadratrac is swapping the tailshaft in your transmission. The TH400 needs to be completely disassembled and the tailshaft swapped out for the correct tailshaft. I didn't need to swap axles or drivelines when I swapped to a Dana 20 in my Cherokee.
    -Jonny B.
    1979 Cherokee Golden Eagle - UNDER CONSTRUCTION
    7" Alcan springs, BJ's HD shackles - 35x12.5x15 BFG Mud Terrains
    AMC 401 - Pro-Flo 4 EFI
    NV4500/NWF BB/NP205 - Triple Stick'd
    F D44 - 4.10, Eaton E-Locker
    R M23 - 4.10, Detroit Locker

    1979 Cherokee Chief - Parts
    1979 Cherokee Chief - Parts
    1979 Wagoneer - Sold
    1981 Cherokee Chief - Cubed


    • #3
      Yeah, what he said...

      Also, your rear diff wouldnt have to be centered. The driveline doesnt know if its at an angle or not regardless of your transfer case.


      • #4
        Didn't know about that- side to side angle makes no difference?

        Hi Guys-

        Did not know that side to side angle does not matter. This stuff is relatively new to me, and all I'd read so far is stuff like-

        'Get everything aligned'
        'Make the angles right'
        'Figure out all arcs of travel'

        So, I'd thought a offset t-case needed an offset diff, centered needed centered, etc.

        Wow. Learn something new about this FSJ stuff all the time. Thanks!


        • #5
          Just MHO but the T18A/208 combo in a 3.73 geared J-20 is a sweet all around useful combo and I would jump through whatever economic, time, repairs, hoops needed to keep the set up you have. Internet swaps don't necessarily mean 'better'. Ya got a good system...fix it.
          "Don't mind me. I'm just here for the alibi"


          • #6
            Hey, Joe- any thoughts on the QT?

            Hi Joe.

            Maybe you might know way more about this than I do, please feel free to chime in.

            I don't hate the QT. One of the PO's did the part time thing, it now has hubs and that knob in the glove box. Before I learned who Flint was or that he posts here, I stumbled onto Jubilee Jeeps a few years ago. His QT articles and info were fascinating. I'm kind of fascinated that mine has the low range.

            One thing that concerns me is that for a while now, I keep reading and seeing pics, of the import QT chains failing- broken link pins, shredded links,
            even some cases with holes ground through them after the chain flew apart. The claim in these stories is that no one was hot dogging it, no hardcore wheeling, just average stuff.

            That's one of the reasons for investigating a gear drive case. I don't really care about "NVH", if a t-case whirrs a bit, fine, it's a Jeep, not a Caddy.
            My old 66 F250 had a NP435, it sang a bit, but that's part of the character of an old truck.

            Don't know yet if I have an OEM chain or not, just happy the Wag drives right now. Sometime when I get back home I'll have to check stuff out more in detail.

            Have you perhaps heard of some guys stashing some domestic chains? I know most old car guys have some spares, even if they never use them, they have them. Figure if I'm gonna run a QT, better get some good spares.
            Hopefully somebody has some that they realize they just aren't gonna use.
            My Jeep is my daily driver. It won't be a hardcore wheeler, but it will get driven off road too, when I can. Been thinking about adapting a 700R4 in place of the TH400 (Advanced Adapters makes a piece for this!), and possibly changing gears too. Not sure yet, think I might have 3.07's.

            So.....any and all comments, thoughts, etc. are welcome, Joe. I know I've got to learn more stuff, and this place has been great to visit.

            Thanks for listening, have a good week.


            • #7
              Hi bmax, re-reading this I think I got mixed up with another thread about a guy with a bent trans shaft in an 80's J-20 T18/208 and suggested fix it. Sorry bout that. My thoughts on a BWQT is that I like'm. Tough decent fulltime case. for normal use. I haven't owned one in ten years and back then repair parts were not made anymore. Now it appears even quality maint parts are rare at best. If yours has the MM conversion kit installed the chain will be new(different length than OEM) so it should be good for awhile. Assuming the rest of the QT was in decent shape before the conversion you should be good to go for at least the near future in a DD. I have no idea about swapping in a D18. A later D20 is a much more common swap. Good to plan ahead but likely not needed for awhile. Yeah you hear about the occasional catastrophic failure but not that common if you keep an eye/ear on chain slack and keep the fluid clean. Trouble with internet forums is you only hear about failures and repairs and pretty soon you're imagining the boogie man under the bed. Even if you're not up for a future D20 swap or a used QT no way is a Chev swap gonna be easier or cheaper not counting the YUK factor.
              "Don't mind me. I'm just here for the alibi"


              • #8
                Hey, Joe....part 2

                Hi Joe-

                No probs....sometimes keeping track of threads/comments gets me a bit jumbled, too.

                Have no clue if my QT is 'straight' part time, or OD part time. Need to clean up the underside, and start taking notes, when I get back.

                Oh- haha....NO chebby swap for me. It's 3604V currently, TH400. Just recently learned about AA's QT adapter piece for the 700R4, was thinking an OD trans would be a nice option.

                If I ever was to swap engines, another Nash/Rambler/AMC is going in there.

                I know that Dana 18 can have a Saturn OD plugged into the back end, and also learned you can get an adapter for D20 to 700R4 as well. So, there are OD options if need be.

                Thanks for the inputs, Joe. All info is welcome, especially first hand, "yeah, I built, or drove that" type of stuff.


                • #9
                  Originally posted by bmax65

                  Thanks for the inputs, Joe. All info is welcome, especially first hand, "yeah, I built, or drove that" type of stuff.
                  I'm working on a solution to the chain issue, but it's at least 6mos out. Don't get your hopes up, but don't despair either.
                  2012 Winner of the Prestigious Ouray Cast Iron Butt Award
                  79 J-10 - The Money Badger!
                  What's been did:
                  Holley 4160/Ede' S.P.2.P.
                  MSD Streetfire based TFI
                  Custom-hack gauge cluster
                  Razor swap
                  Fancy exhaust (Thrush Muffler)
                  2 knob tape deck!
                  3" homebuilt lift
                  Half a hillbilly paint job


                  • #10
                    Here's a curve ball for you Brian. 23 spline AW4 (only "special" part to bolt it to the motor is a re-balanced flexplate. Mine for the 304 cost me $100) 1" spacer ring (also $100), and NP208D (for passenger's drop) It would require a custom bracket to attach an XJ Throttle Position Sensor to move with the carb (to control the trans) as well as the TVS cable. Trans controller harness for an AW4 and Trans Control Module (have a bunch already) Need to hook up the NSS (Neutral Safety Switch) to the solenoid and power up the harness when the key is on.
                    Driveshaft lengths would be custom (I'll have the size for the front soon) as well as trans crossbar (I'm using a Comanche one for template) It should only be about 4 1/2" longer than a 727/NP208 combo and the same as 727/NP229. A custom shifter rod is easy (straight from the column to the trans worked in the Spirit you used to own that we converted into an Eagle)
                    Jeep gauges are for amusement only. Any correlation between them and reality is purely coincidental.


                    • #11
                      Hi Redone

                      Hi Redone-

                      Wow, that sounds interesting.

                      I'm not a fab guy, but am interested in fab and design and possible adaptation stuff.

                      This may sound completely outer space, so be it....

                      One thought I had from my old motorcycle shop days. For many years, several companies offered belt drives for Harleys, some had open primaries, some closed. Gates HTD Polychain belts, if I remember correctly. Belts are used on Top Fuel dragsters, even some helicopters. High hp, torque, and shock load apps...way more than 99% of FSJ's would ever see.

                      After viewing Flint's pics on Jubilee Jeeps....had a preliminary idea.

                      Get some aluminum or even steel plates. Start making tracings of the QT case halves, transfer to the plates.

                      Get the basic center to center dimensions of the QT input/output shaft locations, the bearing locations, etc. Measure all OD's of components.
                      Include the optional low range unit into all this.

                      Now something I'm not sure how to describe....but where the gear/chain teeth are on the sprockets, see if perhaps there is a comparable blower pulley, that could be 'hollowed out', leaving just the ring of belt teeth remaining, to initially slip over the existing sprocket units.

                      I have no clue how the new math would work out, new OD vs. old OD, but suppose that could be worked out.

                      Another idea from the Harley belt drive primary- figure INTO this new t-case, an idler/tensioner pulley. No slack compensation seems to be a major gripe about the QT.

                      This may sound crazy, or like a whole lot of work. But with belts available for super high hp/tq applications, why wouldn't a belt drive t-case work?

                      What I have no clue about, is if any belt is designed to work in a wet environment- QT soup or ATF....that I just don't know.

                      It might end up physically looking something like an Atlas or KluneV in appearance, unless you got a 3D printer/scanner to cast/form up all the little ribs and bosses of a stock QT case.

                      Well, that's the thought....asbestos suit on, let the flames begin....


                      • #12
                        Same thought, go to a modern tcase,,,not a dinosaur.

                        The D18s are noisy,,,etc.
                        And a $700 conversion kit before you find a tcase doesn't sound like a drop in to me......

                        Our TH400 to Dana 18 & Dana 20 conversion

                        J20 project
                        BP Drivetrain...........

                        Driveshafts for all Jeeps, Constant velocity rebuilds, Replacement, Repair


                        Putting this back up. "Someone is gonna have to crawl under the rig"