10 bolt to 12 bolt direct bolt in?

Discussion in 'Transmission & Driveline Topics' started by xten, Jan 22, 2018.

  1. xten

    xten Veteran Member

    1,010
    417
    Sep 24, 2014
    Pittsburgh, Pa.
    Maybe, maybe not. Some people say it is. Took my 10 bolt out today, put a 12 bolt in. Now driveshaft is too short. It'll work, but the yoke doesn't go into the trans (4 speed) far enough. Anyone else run into this? Get longer yoke or get new driveshaft built? I had a jacked up K10 years ago and put a longer yoke to the transfer case and it was fine for years. Really don't want to get a new driveshaft, it's just a cruiser. Not gonna be doing any 6K holeshots.
    Thanks,
    Phil
     
  2. 70 SS/L78

    70 SS/L78 Veteran Member Lifetime Gold Member

    2,358
    32
    May 5, 2005
    Rockford, MN
    That's strange.. far as I know it should be a direct bolt in. I did the same thing to a 70 Camaro back in the mid 80's and had no problem. Same driveshaft worked just fine for me and I did many 6-7K holeshots!
     
  3. big gear head

    big gear head Veteran Member

    5,917
    23
    Jul 30, 2001
    Central City, Ky.
    Depends on which 10 bolt you had. The 8.2 10 bolt uses the same drive shaft, but the pinion is longer on the 8.5 10 bolt, which requires a different drive shaft. When switching from the 8.5 to the 12 bolt you will need a longer drive shaft.
     
    dave@ztech likes this.
  4. xten

    xten Veteran Member

    1,010
    417
    Sep 24, 2014
    Pittsburgh, Pa.
    LOL! That's what I was told too. Getting a new driveshaft made tomorrow.
    Thanks,
    Phil
     
    Last edited: Jan 23, 2018
  5. xten

    xten Veteran Member

    1,010
    417
    Sep 24, 2014
    Pittsburgh, Pa.
    Didn't know that. I guess it was the 8.5. Never had it apart. My driveshaft is an inch too short. I was looking at the pinion yoke on the two rear ends today, and I noticed that the one on the 10 bolt is longer(deeper) and would set the whole driveshaft an inch forward.
    Thanks
    Phil
     
  6. BigBlock73

    BigBlock73 Veteran Member Lifetime Gold Member

    1,859
    14
    Jul 10, 2002
    Accord,New York
    I just dealt with this same issue.
    Replaced 10 bolt with 12 bolt years ago.Had the trans out to deal with 3rd gear popping out.
    Realized slip yoke was sticking out 1 3/4"
    Searched on line and found it should be 7/8"
    Had a new one made and installed it yesterday.
     
  7. xten

    xten Veteran Member

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    417
    Sep 24, 2014
    Pittsburgh, Pa.
    That's my plan also for today. My 10 bolt was making bearing noises, and it needed axle bearings and a pinion bearing. and I priced everything new, and it would have been as much as the 12 bolt I bought already done. And I would have had to pay someone to set them up. How did yours work out? There's a sequence to get my driveshaft in and out (out of the rear end, out of the trans, over the trans, back over the rear end, etc)because of the X pipe and the transverse muffler. I've had it out many times, and I always forget how. lol. Also had the fuel tank out yesterday to fix gauge. It was the connection for the wire to the sender. Seemed like a lot of work just to clean a terminal, since the sender was good, but the gauge will now work.
     
  8. xten

    xten Veteran Member

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    417
    Sep 24, 2014
    Pittsburgh, Pa.
    Got the new driveshaft made yesterday. I had to paint a bumper black, so I put it in the booth with the bumper, so now I have a black driveshaft. Couple things to button up, and hopefully take it for a ride tomorrow. Supposed to be 55° and sunny.
     
  9. camarochevy1970

    camarochevy1970 Veteran Member

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    Jan 23, 2003
    Pittsburgh, PA
    Aren't you worried about the salt on the roads around here? Since it snowed a little last night, and flurrying again now, I think they salted again
     
  10. xten

    xten Veteran Member

    1,010
    417
    Sep 24, 2014
    Pittsburgh, Pa.
    It is a concern, absolutely. The car's from California, but it doesn't seem to take long for Pa. to take it's toll. I'm just getting antsy. lol. It's supposed to be 55° tomorrow, and I'd really like to see if I got the noise I've been hearing, or if it was also in the trans. Maybe a short ride? Probably won't take long to figure out.
     

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