Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Bolt length on ring gear bolts 14bff

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 4X4HIGH, Mar 17, 2002.

  1. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    How long are the bolts for the ring gear on a 14BFF? I purchased a master kit and the bolts are way too short. They would only enter the ring gear by .140". It seems that the bolts need to be .500" longer. The bolts that came in the kit are 1.725" long. What is the difference in the master kits from 1988 and earlier versus 1988 and newer? My 14BFF is out of an 86 sub. but they sold me a kit for 1988 and newer, maybe this is where the trouble is.
     
  2. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    Sounds like you may have gotten the wrong bolts. Did you do a gear swap? If so, there are two different carrier switches for the ratios. You could have gotten the bolts that were meant for one carrier and not for the "thicker" carrier. Just a thought.

    Another thing, you said your 14FF is out of an '86 Sub? Not possible. Sub's in these years have the Semi-Floater rears. Unless you got a FF from a 1 ton or an older truck.
     
  3. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    Here is what I have bought, new case for 4.56-up, 4.56 gears, detroit locker, and install kit. The kit they sold me is for 1988 and newer but the axle is a 1986. I did pull this diff out of a 1986 2WD, 454/400, sub that was all stock, I checked it out from the VIN number as well as the code sheet in the glove box.
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    What is the difference between the case splits other than the 4.56-up case locates the ring gear closer to the pinion? Is the case thicker than a 4.10-down? If this is the case then I need the kit for the 1988 and earlier which should have the correct bolts.
     
  5. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    There are two case splits. The 4.10 and higher gears, and then the 4.56 and lower gears.

    If you had the 4.10 carrier and wanted to use the 4.56 or lower gears, you could buy aftermarket "extra-thick" gears so you would not have to waste the money on a new carrier.

    So, yeah, the carriers between the 4.10 and 4.56 have different thicknesses.
     
  6. nvrenuf

    nvrenuf NONE shall pass! Premium Member

    Joined:
    Jan 7, 2002
    Posts:
    13,081
    Likes Received:
    250
    Location:
    Mobile, Al.
    Forget about the year models, they are NOT the problem. As stated by "thatK30guy" the cases are different depending on the gear ratio. The bolts for a 4.56 / up carrier are longer than the bolts for the 4.10 / down carrier. The reason for this is that as the ratio gets numerically lower the pinion gear gets progressively larger in diameter (more teeth) causing the 4.10 / down carrier to be thinner.

    You have a kit with bolts for a 4.10 type carrier. I would think that whomever you bought the kit from would simply swap the bolts for the correct ones. Good luck!
     
  7. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    Hey thanks man, I figured that i had the wrong kit. Now I will check it out tomorrow and see about getting the correct bolts from the other kit that is available. I doubt that the bearings would be different only the bolts.
     

Share This Page