Pinion yoke question

Discussion in 'Got gears?' started by Mr. Sunset, Nov 15, 2016.

  1. Mr. Sunset

    Mr. Sunset Platinum Level Contributor

    Can the stock yoke on a 71 8.5 10 bolt be changed out to a new 1350 series yoke without resetting the ring and pinion gear.
    is it an off and on process ?
    I am looking into driveshafts and was recommended to use the 1350 series yokes front and rear.
    granted i'm only at 426 HP I am turning 5500 rpm.
    the stage 2 heads and headers upgrade in a few years will add to that.
    Also if you have any advise on driveshafts i'm interested.
     
  2. monzaz

    monzaz Jim

    Yes. Just have to be careful putting the nut back on the pinion and only drawing it to the same preload...THEN you need to stake the nut in place with a steel punch lock tight it also. You will be fine. If you over tighten it you will burn the bearing up...do not tighten enough the pinion will climb the ring and make whining noise and wear the gears off pattern.

    The proper way would be to get a new crush sleeve and remove the carrier etc. BUT I do totally understand what your trying to do... Just have to use the tricks I gave you and check it periodically to be sure you do not have the nut backing off etc. Good luck, Jim

    J D
     
  3. Mr. Sunset

    Mr. Sunset Platinum Level Contributor

    I have already pulled the pinion yoke on bad advise that it's easy on easy off. I didn't think it was that easy.:Dou:
    I will have to continue with assembly and get it to a local rearend shop
    That may be a good time to switch to 3.73 gear. I do have the 4th gear using the 4l80e trans.
    I know there are folks here running 3.73 with overdrive.
    Not knowing what the preload was...any advise to proceed?
     
  4. monzaz

    monzaz Jim

    I do not know what it is your asking on advise for..lol ?? Jim
     
  5. Mr. Sunset

    Mr. Sunset Platinum Level Contributor

    Is there a trick of the trade for example
    install the nut finger tight the turn it a quarter turn.
    or turn the nut until it stops then back it off half a turn.
    I guess I'm asking how do I get it close so I can at the very least
    drive to a shop and change out the crush sleeve and/or gears without
    destroying all of the brand new parts inside.
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    My guess is it is too late for that. I think you could have marked the nut and payed careful attention to how many turns it took to come off, then put it back to where it was. I believe you tighten the nut and check how much torque it takes to rotate the pinion, but Jim could advise you further.
     
  7. monzaz

    monzaz Jim

    It really is just a feel thing and experience. If you just tighten the nut by hand you are NOT going to crush the sleeve anyfurther. SO tighten it on stake that nut or use lots of red lock tight and drive it to the shop. You will be fine. Jim
     
  8. philbquick

    philbquick Founders Club Member

    The way the GM Manual say to to it is to measure the preload before you take the yoke nut off (too late for that now) and add 5 in lbs to that value with the new yoke and seal. For example: if your reading was 5 in lbs before, you set it to 12 in lbs with the new stuff. When you take your reading, do it with the rear drums off, or better yet, with the axles out.

    Measuring preload isn't that big of a deal, I use a 1/4" flex beam torque wrench. You can also use a broom stick, a 1 pound weight and a tape measure. Take a 3 ft piece of broom stick and bolt it into the "U" bolts on the yoke centered. Turn the stick so it's horizontal and hang the weight on one side of the stick near the yoke. Move the weight away from the yoke in small increments until the yoke begins to turn, then measure the distance from the weight and the center of the nut and that's your preload.

    The pinion preload sets at 18 in lbs when the bearings are new. I did my 65 last year the preload was at 2 in lbs before disassembly so I ended up at 7 in lbs with the new seal in. So, with a car that has 52K miles on it the preload was almost zero. Hope this helps.
     
  9. wkillgs

    wkillgs Gold Level Contributor

    It takes a LOT of torque to compress the crush sleeve....and that's using a 3 or 4 ft long breaker bar!
    I'll guess you can safely torque the pinion nut to 100 ft lbs and not crush the sleeve further. What do you think Jim?
     
  10. Mr. Sunset

    Mr. Sunset Platinum Level Contributor

    Thanks Jim. It was my driveshaft builders son that stated it's no big deal. that they torque them on and off all the time. Again..Just because there in business does not mean they know what they are talking about. seen this too many times. I never felt comfortable with the guy that assembled the rearend anyway so not really a big deal to bring it in. also those 3.73 gears. I got the 3.42s when I was using the t400 trans.
     
  11. Mark Demko

    Mark Demko Well-Known Member

    X2, when I replaced the pinion bearing in my wifes Safari van a few years ago, I had the same issue, but it does take A LOT of torque to crush that sleeve, I tightened it as far as I could with a 1/2 inch ratchet, then a couple zings with an impact, called it good, crossed my fingers, and its been quiet since then:beer I think I got lucky:TU:
     
  12. monzaz

    monzaz Jim

    I would not go that far 70 is fine ... if you do not have a torque wrench do not sweat it. Just tighten it as much as you can with a 1/2 rachet and use the lock tight and if you can stake that nut...Stake the nut only if you think noone else is going to take it apart anytime soon. In Mr Sunsets case - just lock tight the nut and get it to the shop you will be fine. Jim
     
  13. Mr. Sunset

    Mr. Sunset Platinum Level Contributor

    that helps, 70lbs isn't much but tighter then I thought it should be. thanks.
     
  14. philbquick

    philbquick Founders Club Member

    Preload and the torque required to crush the sleeve are 2 completely different things. The crush sleeve is springy to a certain extent and you can get away with backing-off preload maybe 1/8 turn if you over-shoot. Since you are changing the yoke all bets are off since the yokes may be from different manufacturers and may have different dimensions on the end shoulder.
     
  15. monzaz

    monzaz Jim

    He is just trying to get to a shop. NONE of this makes any difference.

    There is NO specific toque for the pinion nut. The torque is what it takes to crush the pinion sleeve. When crushing the sleeve you can only go in the ON position... If you go too tight and over crush you need to get another sleeve and start over.
    Preload is the constant torque it takes to spin the pinion system with out the carrier installed in the housing cavity.

    Hope that clears up the gray area.

    Jim
    J D
     
  16. philbquick

    philbquick Founders Club Member

    No gray area here, I've been doing this a long time.
     

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