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.

gear ratio question

Discussion in 'The Garage' started by lukc22, Nov 8, 2005.

  1. lukc22

    lukc22 Registered Member

    Joined:
    Feb 21, 2005
    Posts:
    48
    Likes Received:
    0
    Location:
    texas
    I am looking to find out the front and rear gear ratio to my truck... The front is the original axle of an '82 1/2 ton diesel and the rear is a 12 bolt out of a full size blazer (I think it's an early 80's model)... I have a code off of the back axle that reads "KAJ W196 2 F"... Can anyone tell me what ratio I have or what other information that I need to get to determine that??... The glove box does not have the sticker that would contain the codes... Thank very much!!!
     
  2. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,537
    Likes Received:
    921
    Location:
    Massachussetts
    Call the dealer..

    The chevy dealer's parts department has the axle codes listed in their catologs.."KAJ" sounds like an axle code,if you got that off the axle tube somewhere..so if nobody here can tell you,call the dealer..they shuold be able to help.. :crazy:
     
  3. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

    Joined:
    Apr 5, 2003
    Posts:
    998
    Likes Received:
    592
    Location:
    Pueblo, CO
    Have you tried spinning a tire and watching the driveshaft? This will get you close without having to open op the diffs. On the rear axle, Chock the front wheels, shift the trans into neutral, jack it up (support it with jackstands) mark a spot on the driveshaft and on one tire. Rotate one tire (you will have to hold the opposite tire on an open diff, get a buddy) 1 full revolution. While turning the tire count how many times the driveshaft made a complete revolution. 3 3/4 turns would be for a 3.73, just over 4 turns would be 4.10s and 4 and a half turns would be 4.56's

    You can do the same for the front, you just have to lock the hubs in and leave the t/case in 2hi.

    Reason you have to hold the opposite tire on an open diff is turning one tire will only rotate the spider/side gears and not turn the ring gear.

    It's an quick and easy way to get an idea of what ratio is inside. Great for use in the boneyard looking at axles.
     
  4. lukc22

    lukc22 Registered Member

    Joined:
    Feb 21, 2005
    Posts:
    48
    Likes Received:
    0
    Location:
    texas
    hey guys, I really appreciate the info ... I am trying to learn and hints like that help out alot when I really dont know what I am doing .... I will definately give that a try!!! :}
     
  5. dcubb

    dcubb 1/2 ton status

    Joined:
    Jan 18, 2005
    Posts:
    187
    Likes Received:
    0
    Location:
    Pickens, SC
    Do what ZooMad75 said, except, with an open diff rotate ONE wheel exactly TWO revolutions with the other wheel stationary and with a posi, spooled, locked, etc diff rotate BOTH wheels together (duh) exactly ONE revolution to achieve the same result. This is a very effective method of determining the gear ratio in any axle.
     

Share This Page