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1968 V6 To Dana 30 U Joint

Discussion in 'Early CJ5 and CJ6 Tech' started by masscj2a, Jul 11, 2021.

  1. masscj2a

    masscj2a Member 2023 Sponsor

    I've swapped in a 78 Dana 30 front axle in my 68 CJ-6 with a dauntless. I can't find the part number for the offset u-joint to go from small drive shaft to I believe the 1310 input yoke on the 30. Any help would be greatly appreciated. I'll continue to dig to see if I can find it. Thanks.
     
    masscj2a, Jul 11, 2021
    #1
  2. FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    I think most people change the yoke more than look for a hybrid u-joint?
     
    FinoCJ, Jul 11, 2021
    #2
    RATTYFLATTY and mortten like this.
  3. garage gnome

    garage gnome ECJ5 welder

    Probably easier to put a big yoke driveshaft in. IIRC, the D30 yokes have more splines than a D25/27. Been a while since I had my D30 apart.
     
    garage gnome, Jul 11, 2021
    #3
  4. masscj2a

    masscj2a Member 2023 Sponsor

    The problem with a big yoke driveshaft is the starter. I have a big yoke rear which was stock but they put a pencil small one up front with the Dauntless starter. I have nothing here to swap out.
     
    masscj2a, Jul 12, 2021
    #4
  5. masscj2a

    masscj2a Member 2023 Sponsor

    James which yoke the Dana 30 ? I didn't know they made a finer spline count small u joint one. But tell me where I can get one.
     
    masscj2a, Jul 12, 2021
    #5
  6. FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Many others have done this D30 swap in place of the D27, and I have not, so I may be wrong, but I have done my best to research it....As I have the v6 as well, it has the small yoke/ujoints on the front driveshaft as you know. I think people have solved this a few different ways:
    1) swap the differential end half of the driveshaft for one that will fit the larger u-joint and thus leave the D30 yoke the same...maybe you have to have a portion of your driveshaft redone at a drive shaft, or maybe you could pluck a portion of a 4cyl driveshaft for one end (not sure how much different the v6 vs F4 driveshaft lengths are). If you could clear the large 1310 u-joint at the D18, then you could probably pluck an entire driveshaft off a 4cyl cj with both ends using a 1310 ujoint?
    2) I think you can swap the D30 yoke for a smaller one to fit the small ujoint - but I don't know that for sure....I think I remember someone posting a link to a place that was selling them....
    3) I think quite a few people have done this swap at the same time that they did 4speed swap, so a new front driveshaft was part of the deal - and I think some had no real issue with running the large ujoint at the TC even with the starter.

    Basically, I guess what I am thinking from what I remember doing this research awhile ago is that you will have to change either the yoke on the D30 fit the small u-joint, or change the driveshaft in some way to fit the larger 1310 u-joint, but there is no 'hybrid' ujoint that has a combination of the large and small ujoint to directly connect the OEM v6 driveshaft to the larger 1310 ujoint on the D30....
     
    FinoCJ, Jul 12, 2021
    #6
    masscj2a likes this.
  7. masscj2a

    masscj2a Member 2023 Sponsor

    I didn't think there was a yoke to fit the small u joint and match the spline count on the pinion of the 30. I keep looking but haven't found a reference to one.
     
    masscj2a, Jul 12, 2021
    #7
  8. Steve's 70-5

    Steve's 70-5 Active Member

    When I did my swap. The front driveshaft usually needs to be shortened. I just put a new yoke on the driveshaft to match the D30
     
    Steve's 70-5, Jul 13, 2021
    #8
  9. Daryl

    Daryl Sponsor

    Best bet is to always get rid of the factory small joint shaft that the slip yoke was worn out by the time the Jeep was driven home from the dealer. Simply no point to keeping a terrible quality shaft that uses expensive joints that Noone stocks anymore.
     
    Daryl, Jul 13, 2021
    #9
  10. colojeepguy

    colojeepguy Colorado Springs

    I think if you have any lift, starter clearance won't be an issue.
     
    colojeepguy, Jul 13, 2021
    #10
  11. masscj2a

    masscj2a Member 2023 Sponsor

    Steve do you know which slip yoke fits the small drive shaft and the Dana 30 pinion?
     
    masscj2a, Jul 13, 2021
    #11
  12. Mr Vaughan

    Mr Vaughan

    i dont think any old jeeps really have slip yokes, especially not on the axles, right?
     
    Mr Vaughan, Jul 13, 2021
    #12
  13. Rozcoking23

    Rozcoking23 RUN & GET BIT! 2024 Sponsor

    I just did this swap. I'm running a sm420 transmission and 2-1/2" YJ lift. I originally changed the transfer case front yoke to the larger one. I ordered a drive shaft from Tom Woods with both ends with 1310 joints. When I tried to install on transfer case side there was not enough room for the joint to spin. Tom Woods did me a solid and took back the drive shaft and built me a high breed, with the small joint on transfer case side and the 1310 joint on the axle end, at no additional cost. Great company to work with.
     
    Rozcoking23, Jul 14, 2021
    #13
  14. Steve's 70-5

    Steve's 70-5 Active Member


    I just took my front drive shaft to a shop. The slip yoke is at the transfer case. The shop just cut the yoke off at the D30 end and welded a new one on the match the D30
     
    Steve's 70-5, Jul 14, 2021
    #14
  15. termin8ed

    termin8ed I didn't do it Staff Member

    I need a new front shaft now, but when i did my swap i ended up swapping the tcase yoke out to a larger one and modified a front shaft from a cj7 or wrangler or cherokee?:shrug: maybe? I do remember cutting it down to fit a couple times. I do have a 2" lift so no starter issues.
     
    termin8ed, Jul 14, 2021
    #15
  16. garage gnome

    garage gnome ECJ5 welder

    Mark, I have a driveshaft with a big u joint on the slip joint end and a small on the axle end. You could just do the opposite of what I described.
     
    garage gnome, Jul 15, 2021
    #16
  17. masscj2a

    masscj2a Member 2023 Sponsor

    Nate sounds good. When are you around? I can drive over in the new cj6. Took it out for a first short ride tonight.
     
    masscj2a, Jul 15, 2021
    #17
  18. garage gnome

    garage gnome ECJ5 welder

    The driveshaft I was referring to is the opposite of what you need for your jeep, small u joint on the axle end and large on the transfer case end. You need a large on the axle end and small on the transfer case end. It is also a very long one from a T98 equipped jeep I had. What I meant to say is, you could take the small slip joint end and put it on a large u joint driveshaft making a hybrid unit.
     
    garage gnome, Jul 15, 2021
    #18
  19. Warloch

    Warloch Did you say Flattie??? Staff Member

    Not sure why folks have the binding issues - I have the SM465/D18 setup with the standard large yoke 1310s on it as well as the factory D30 yoke. Worked fine for years now. Mostly you need a bit of lift - just a couple inches - to clear the starter. Its also why there was the arm on the D27 on that side to limit the articulation originally.
     
    Warloch, Jul 15, 2021
    #19