Combination U-Joint 741 to 742 Swap

Engine, Trans & Driveline

  1. 1 Wild R/T

    1 Wild R/T Well-Known Member

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    Hate to say it but did you ever think Cass could be wrong? Find me a set of gears for a 741 or 742 with the 31 spline...... I'll wait...
     
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    • Fran Blacker

      Fran Blacker FBBO Gold Member FBBO Gold Member

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      Found a plain 454 in moog has nothing I can see with your part. grease fitting position isn't important unless your making some serious HP. MO.
       
    • Belvedere13

      Belvedere13 Active Member

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      https://www.doctordiff.com/pinion-nut-and-washer.html

      If a 1 5/16" or 1 1/4" socket fits your original 8 3/4" nut, you have a 29 spline pinion. Otherwise, your 8 3/4" has a 10 spline pinion.
       
    • Belvedere13

      Belvedere13 Active Member

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      Fran...No major HP...Yet :rofl:
       
    • Belvedere13

      Belvedere13 Active Member

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    • 1 Wild R/T

      1 Wild R/T Well-Known Member

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      Those are aftermarket gears... Fine spline was only used on 489... 741 with fine spline is a very recent thing, maybe ten years......

      Notice that Case specifically states "your original 8 3/4" nut"

      Hey, no big deal like Burger King sez, have it your way....
       
    • BSB67

      BSB67 FBBO Gold Member FBBO Gold Member

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      As Fran mentioned, probably a 1330, not a 7290 on the 742 side
       
    • Belvedere13

      Belvedere13 Active Member

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      Thanks BSB67...That's probably the route I'll be going.
       
    • BSB67

      BSB67 FBBO Gold Member FBBO Gold Member

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      In hind sight, I'm not sure I answered your question. Honestly, I got lost on where this discussion went.

      If I'm correct, and the 7290 does not fit, and it needs to be a 1330, you can simply put 1330 caps on the 7290 side if the joint.
       
    • Belvedere13

      Belvedere13 Active Member

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      Not to worry...it's been a real "joy" from the git go with the mis-information I've been given. I'm hoping the local vendor can be flexible when it comes to "dry fitting" things...
       
    • Paul Secoy

      Paul Secoy Well-Known Member

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      I've collected and pulled apart quite a few 8-3/4s, and I'm pretty sure the fine spline was only used on 489 cases also. Good luck to the OP either way.
       
    • Belvedere13

      Belvedere13 Active Member

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      Have you encountered any non 8 3/4" 489 cases with a 1 3/16" or 1 1/4" pinion nut?
       
    • Paul Secoy

      Paul Secoy Well-Known Member

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      I can't say I ever paid any attention to the nut sizes, I used whatever socket fit :) I just don't think I have ever seen a fine spline yoke anywhere but on a 489. Did you find a U joint that worked for you?
       
    • Belvedere13

      Belvedere13 Active Member

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      I guess that's what I get for believing the "Internet" in regards to the pinion nut size versus the spline count. I'm going to try a Moog 457 when it arrives. It's not like I have other pressing engagements currently...
       
    • Fran Blacker

      Fran Blacker FBBO Gold Member FBBO Gold Member

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      This isn't fact. The yoke on my 66 for 1330 u-joint, don't think I could get a socket on an 1 1/4" nut. Are the 1-1/4" nuts single use nuts, egged shape to lock. The 1-1/8" nut on my 66 has small slots on top assume to help lock nut?
       
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