1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Which 4-speed?

Discussion in 'Early CJ5 and CJ6 Tech' started by Bowbender, Sep 3, 2017.

  1. Sep 9, 2017
    Muzikp

    Muzikp Active Member

    Sacramento Ca.
    Joined:
    Sep 27, 2016
    Messages:
    1,450
    Another vote for the SM420 here. Really like mine.
     
  2. Sep 10, 2017
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    Wouldn't that put your shifter way back between the seats. ?
     
  3. Sep 10, 2017
    tarry99

    tarry99 Member

    Northern California
    Joined:
    Oct 29, 2012
    Messages:
    3,784
    YES!
     
  4. Sep 10, 2017
    Daryl

    Daryl Sponsor

    Bonney Lake, WA
    Joined:
    May 25, 2006
    Messages:
    2,871
    Not if you move the motor forward. There is a lot of room if you are willing to use it.
     
    ITLKSEZ likes this.
  5. Sep 10, 2017
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
    Joined:
    Aug 13, 2015
    Messages:
    6,656
    It comes out a few inches further back than stock, but how many four speeds can you swap in without doing some sheetmetal work on the floor?

    It's just another option. Like anything in a build, it's all about trade offs.
     
  6. Sep 10, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596

    Just a comment on this - the Buick 350 was offered in the full-sized Jeeps (FSJs- wagons and trucks tracing back to the 1964 design) nominally for only three years (1968-1970) - Jeep gave these cars the 360 in 1971; in the 1970-71 period, there was a time when buyers could specify the 350 or 360 for delivery, so some "1971s" got the 350, and perhaps some "1970s" got the 360.

    Note that Jeep sales of these models, especially the J-trucks, was not particularly strong in this era - nothing like the Big-3 sales of light trucks. Ford has sold somewhere around a million units of light trucks per year for many decades. I'd guess Jeep sold maybe 10,000-20,000 J-trucks in 1970? Wagoneers were sold almost entirely with automatic transmissions. In this era, Jeep used the excellent TurboHydro 400 from GM in all models with an automatic, and it was very popular. Strong, smooth, durable, reliable. The main hit on the TH400 was poor efficiency which led to more fuel consuption, but this was much less of a concern to buyers in 1970 than in later decades.

    Typically you'll find this setup with a T-18 in a J-truck that someone bought to work on the ranch or to haul their slide-in camper. These trucks were never plentiful, and these Buick-equipped trucks are desirable if you want to keep the original drive train of the truck. Some Wagoneers came with the T-18 and I imagine their owners used them to pull travel trailers or horse trailers.

    So while this combo can work, I think you'll have a tough time finding it today. That long one-piece bell for the 350 is almost unobtainable (NB there is a similar long bell for the AMC 327 that does not have the BOP pattern - so bear that in mind if you look for this combo). And you are adding an extra constraint - added length - that you would not have with the Ford short input T-18 version. If you are willing to take the transmissions apart and do a little drilling and tapping, you can combine a Ford T-18 and any Jeep or IHC T-18 to make what's essentially the same as the Ford T-18 and Novak's adapter kit. I have not done this, but Nick has discussed it several times in these forums. Recall I mentioned that Ford produced something like a million light trucks a year for decades? Many of those trucks got a short input T-18, and they are plentiful.

    Finding this combo today for a reasonable price will depend mostly on luck, I expect. If one turns up right away, great, but I kinda think it's worth more to the FSJ crowd than as a conversion transmission for a CJ-5. If you want to go the junkyard route, I think you are a lot better off to look for whatever Jeep/IHC T-18 you can find at a reasonable price.

    You should be able to use a IHC T-19 too, though I don't know offhand what the issues are with that. IHC used both the T-18 and T-19, but Jeep only ever offered the T-18. The only T-18 offered by Jeep after 1979 was the T-18 in the J20, and that's not going to work for you. In addition to the very long input, it has a very long output with a 6" long output adapter to NP transfer cases and unusual 31 spline output - I believe it's the same as the late Ford 4WD T-18s from the case back.
     
    Last edited: Sep 11, 2017
    Bowbender and ITLKSEZ like this.
  7. Sep 10, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Yeah that'l work if your willing to run an aftermarket maindrive shaft.
    Truth is that all the various low geared T18's will require some sort of modification in order to fit it into a short (80 or 81") Jeep CJ.
    It's simply a matter of getting the T18 that best suits your particular tools and ability.

    The Ford T18 requires ample drilling and tapping.
    Plus you have to rob a Jeep or IH version of it's mainshaft and rear adapter plate to make the Ford fit your transfer case.
    The 1977-1978 CJ T18 is a direct fit to transfer case but requires either a custom thin adapter plate or some case welding up front.
    All other T18's will mandate bellhousing changes and /or maindrive gear change out.
     
    Bowbender likes this.
  8. Sep 10, 2017
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    Are there known problems with the aftermarket shafts?
    I have a long input T18 that I was planning to convert to a short shaft to put in my Jeep...
     
  9. Sep 11, 2017
    Bowbender

    Bowbender I'm workin' on it!

    Northern Minn.
    Joined:
    Nov 14, 2014
    Messages:
    561
    Well, my search for a T18 was a fairly short one. I stopped at a local salvage yard, turns out the man I talked to is a "JEEP guy", he knew exactly what I was looking for and has done the conversion a few times. I ended up with a transmission from his "personal stash".
    [​IMG]
    He also thought he could find an adapter plate for between the T18 and the transfer case. He thought he "might" still have a Buick 350/T18 bell housing too. If it's long like the pic posted, I'll pass on it. I'm starting to get my head around what is involved in making this swap. As I gather parts, I will take notes and pics of how I end up doing it, with a build thread in mind. Hopefully to help others who want to do this.
    I appreciate all the feedback.
     
    RATTYFLATTY, 47v6 and ITLKSEZ like this.
  10. Sep 11, 2017
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
    Joined:
    Apr 28, 2011
    Messages:
    5,407
    well what did you give for it .
    still going to need a adapter kit . or another parts transmission
     
    Bowbender likes this.
  11. Sep 11, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Yep. I'm not sure he helped you all that much. That is clearly a 2WD transmission, or 4WD with a divorced transfer case. Could be a T-98 from a M715. What do the numbers on the side of the case say? The Ford T-18 can be adapted easily to a GM bell - check the Novak page on this The Novak Guide to the Adapting Ford Style Transmissions to GM Engines Post a picture of a front view.

    An adapter to the transfer case won't be enough - you'll also need to change the main shaft. This is a job needing a big puller - you need to transfer all the parts from the existing main shaft to the new main shaft. You can get a conversion kit with a main shaft and adapter, or machine the case (drill new holes, tap and plug existing holes, tap new holes as needed) and use a Jeep adapter and main shaft.

    The Novak Guide to the Borg-Warner T18 & T19 Transmissions
    Adapting the Borg Warner T18 & T19 Transmissions to the Dana Spicer Models 18 & 20 Transfer Cases
     
    Last edited: Sep 11, 2017
    Bowbender likes this.
  12. Sep 11, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
    Joined:
    Apr 11, 2012
    Messages:
    1,427
    I have the sm465 in my CJ6 and it works well, but as others have said it's a bit of a packaging issue due to its size. I've put T18 transmissions in a few CJs, and I've had them in Scouts, IH trucks, Ford Trucks and a couple log skidders. They've all given great service. The T18 shifts better and is more compact than the sm465. Durability between the two is similar. I had one SM420, had synchro issues with it. I also developed an anger issue with it as well, but that's another story...A land cruiser friend has one, has synchro issues with his also, plus parts aren't too common for them anymore. Again, I'd vote T18.
     
    Bowbender and 47v6 like this.
  13. Sep 11, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
    Joined:
    Apr 11, 2012
    Messages:
    1,427
    Also, all my T18s were dead silent. My SM465 is a little bit noisy. Nothing bad, all new bearings, but I can hear the whirring from it. Of course, all my log skidders were powered by Detroit diesels, so those T18s coulda been howling like crazy and I'd have never heard them.
     
  14. Sep 11, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    There may be some quality control or durability issues with aftermarket shafts.
    No real way to know until you install and run it.

    If you shorten a long mainshaft it will most certainly go through the case hardening at the new pilot tip.
    Extending or cutting new splines could also be a big concern.
    Maybe Mike Mcruff will chime in on re-machining one to shorter length.
     
  15. Sep 11, 2017
    tarry99

    tarry99 Member

    Northern California
    Joined:
    Oct 29, 2012
    Messages:
    3,784
    That looks like an early Ford truck T-18 with the correct length front input shaft...........With that and the adapter & short main shaft from Novak your in business..........although you should pull the top cover and look at the gear sets..........especially the front input shaft gear that meshes with the counter shaft below.........should be 17 teeth for a 6:32 low gear........also look at the first & reverse sliding gear and counter shaft below in the rear of the case.........those take the most abuse. That transmission can easily be adapted by drilling a few holes in the case & taping two of them to a stock Buick bell housing.........only been done a million times +/-
     
    Bowbender likes this.
  16. Sep 11, 2017
    oldtime

    oldtime oldtime

    St. Charles,...
    Joined:
    Aug 14, 2006
    Messages:
    3,466
    Yeah that's a pre 1979 Ford.
    Now you just need the IH or Jeep donor parts.
     
    Bowbender likes this.
  17. Sep 11, 2017
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Interesting - "silent" is subjective. I know from driving brand new otherwise identical T-14, T-15 and T-18 CJs that the T-18 has more gear noise than the Borg-Warner 3-speeds, most noticeable in 3rd.
     
  18. Sep 11, 2017
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    The OP is adapting it to a model 18 tcase...I don't think noise from the trans is going to be a concern...
    :D
     
    Bowbender, FinoCJ, fhoehle and 2 others like this.
  19. Sep 11, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
    Joined:
    Apr 11, 2012
    Messages:
    1,427
    Silent is truly subjective. My tinnitus probably makes me not really a great judge of noise but they were quiet to me.
     
    cookieman likes this.
  20. Sep 11, 2017
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
    Joined:
    Apr 11, 2012
    Messages:
    1,427
    Yeah, the Dana 18 is a noisy little fella.
     
New Posts