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Diff Gear Question

Discussion in 'Early CJ5 and CJ6 Tech' started by Southtowns27, Aug 5, 2004.

  1. Aug 5, 2004
    Southtowns27

    Southtowns27 Custom Title

    The Backhills of...
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    I found a set of 4.30's for a Dana 44. The question is, can I find a set of 4.30's for a 27 axle? Will 4.27's be compatible? I don't want the T-case to explode! Thanks in advance
     
  2. Aug 5, 2004
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    I'm far from an expert, but I'll say yes the 2 ratios are close enough. But I believe that's about it as far as allowable difference.
     
  3. Aug 6, 2004
    80cj

    80cj Member

    Hawaii
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    Ford used 3.50/3.54 combinations in their Bronco's and F150s. Your 4.27/4.30 is closer than that so it shouldn't be a problem.
     
  4. Aug 6, 2004
    Southtowns27

    Southtowns27 Custom Title

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    Alright, it sounds like I'll get them then... Now I just have to find a set of 4.27's for a model 27 axle. I have 3.73's now and I have a Warn Overdrive on the way so I figured I'd put lower gears in it. I'll effectively have a lower crawl ratio, but with the overdrive a higher final drive ratio... best of both worlds.

    Anyone have 4.27's for sale or want to trade for 3.73's?
     
  5. Aug 12, 2004
    JAB

    JAB Member

    Genesee, WI
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    4.30?????????????????? For a Dana 44??????????????????? Are you sure?

    I just checked the Dana site to be sure I didn't miss something & the ratios in the 4's are 4.10, 4.27, 4.56, & 4.88. You're not mixing ring & pinion gears are you...............if you are it probably won't last too long.
     
  6. Aug 12, 2004
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Aren't you gonna need new carriers too? Isn't the cutoff at 3.90 or thereabout? Thinking more about it, going to 4.88s would be a much better swap.
     
  7. Aug 12, 2004
    66cj5

    66cj5 Jeep with no name

    NorthWest Indiana
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    must be "another" brand.....gm 10 bolt? custom?
     
  8. Aug 12, 2004
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
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    Don't worry you can't mix and match ring and pinion, they won't mesh and fit together at all. What is the gear count to get the 4.30 ratio!!
     
  9. Aug 12, 2004
    JAB

    JAB Member

    Genesee, WI
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    That's my point, but I was wrong once :oops: so now I'm less judgmental :rofl: .
     
  10. Aug 13, 2004
    Southtowns27

    Southtowns27 Custom Title

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    They're Dana gears, the cutoff for the carrier is 3.73 and up, so I should be good there. The tooth count is 10-43 to get 4.30.
     
  11. Aug 13, 2004
    181jeep

    181jeep Banned

    central valley, ca
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    I'm with Glenn on this one. I think the carrier brake for a 44 is 3.94. You better check again on the carrier compatability.

    JB
     
  12. Aug 13, 2004
    66cj5

    66cj5 Jeep with no name

    NorthWest Indiana
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    3.73 down. 3.92 up.
     
  13. Aug 14, 2004
    Southtowns27

    Southtowns27 Custom Title

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    You guys are correct on the carrier break... BUT, I just spoke to the guy with the gears again - These are special gears that work with the 3.73 and down carrier. I guess they're kinda rare. Dana made them for guys like me who wanted shorter gears but had the wrong carrier hence the strange 4.30 ratio. I won't have time to put them in right away, but when I do I'll let everyone know how they work. Thanks for all the input :beer:
     
  14. Aug 14, 2004
    66cj5

    66cj5 Jeep with no name

    NorthWest Indiana
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    whats the height of the gear? the 3.92 up is 1 5/16" high.
     
  15. Aug 16, 2004
    JAB

    JAB Member

    Genesee, WI
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    I seriously doubt that Dana made them (although I suppose it's possibly that some after-market company did..............but if they did then what goes with it in the front? Wouldn't they have a product line to sell?). I seriously doubt that ANYBODY made them. I think you've got a mis-matched set that somebody is trying to sell you. The 43 tooth ring gear is common to several ratios (like my 5.38 for instance) & the 10 tooth pinion is from 4.10, among possibly others. I doubt it'll work. Is the seller a guy you can trust? I think you need to do some research on this before you spend any more money on what is very likely precision scrap metal.
     
  16. Aug 16, 2004
    66cj5

    66cj5 Jeep with no name

    NorthWest Indiana
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    spend the $$$$$ on the right stuff.
     
  17. Aug 16, 2004
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
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    Here is a sure fire way to tell if the guy is blowing smoke up your butt, have him send a photo of the pinion gear markings. Dana stamps there pinion gear with both the tooth count for the pinion as well as the tooth count for the ring gear. If he tries to BS you about the photo and the markings ignore him and move on!!
     
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