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.

stock axle ratios

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 86blazerk5, Aug 10, 2000.

  1. 86blazerk5

    86blazerk5 1/2 ton status

    Joined:
    Aug 9, 2000
    Posts:
    387
    Likes Received:
    0
    Location:
    Hagarstown, Maryland
    Can anyone tell me what the stock axle rationis for an 86 10 front 10 bolt, and for a 79 rear 12 bolt, and weather or not they match? I really would like to know if anyone can tell me. Thanks!

    Ike
     
  2. coopertwpk

    coopertwpk 1/2 ton status

    Joined:
    Mar 18, 2000
    Posts:
    478
    Likes Received:
    0
    Location:
    Spring Valley Lake Ca.
    Yes they match and did yours come with a factory tow package?and if you have a 700r4 most have 4.11 or 3.73 if not they had 3.08.
     
  3. Blazer1970

    Blazer1970 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,600
    Likes Received:
    0
    Location:
    Old Mission, MI
    There are many different axle ratios available for both years. You will have to check the specific axles that you are looking at.

    Tim

    1970 Blazer CST 4X4 350 SM465 NP205
    1987 Suburban 4X4 350
    1988 Chevy Pickup 4X4 350
     
  4. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,082
    Likes Received:
    486
    Location:
    Grand Rapids area
    You can easily figure it out by jacking up the back end and counting the number of wheel revolutions compared to driveshaft revolutions. The front and rear are always the same or else you would rip up your tires and drivetrain in 4WD.

    '85 JIMMY
    '90 paint/grill/trim 5"susp 33/12.5/16.5
    Fresh 350 B&M '87 TH700
     
  5. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Or pull the covers on the and look for the gear ratio stamping on the Ring gear(it will be a number like 41:11), if there is not one, you can count the teeth on the ring and pinion.



    Mike [​IMG]
    1982 GMC Jimmy - <font color=green>Emmett</font color=green>
    http://emmett.coloradok5.com
     
  6. 90K5

    90K5 1/2 ton status

    Joined:
    Jun 1, 2000
    Posts:
    3,719
    Likes Received:
    0
    Location:
    Lubbock, TX
    You can also looke at the RPO codes in the glovebox but someone may have changed the ratios. I dont remember the codes but I think GU6=3.42. Someone will post them. If you have an auto you will probably have 3.42 3.73 or 4.10 if you have a manual you will porbably have 2.73 or 3.08

    90K5
     
  7. 86blazerk5

    86blazerk5 1/2 ton status

    Joined:
    Aug 9, 2000
    Posts:
    387
    Likes Received:
    0
    Location:
    Hagarstown, Maryland
    ok, I have the 700r4 transmission, however my glove box tells me I have 3.42s and a locking differential. i dont have the factory tow package, at least I dont think, i have a tow package, but i dont think its factory. I still need to look at the donar 79 and see what it has on it to see if we have a match or not!!! Thanks guys!!!

    If you can afford it, do it. If not, find a way!!!
     
  8. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,173
    Likes Received:
    1,384
    Location:
    E-town baby!
    The donor '79 will <font color=red> probably </font color=red> be 3.08's. Your 86 has overdrive so the 3.42's are pretty common. The 79 would not have overdrive so the 3.08's were pretty common. I would pull the covers off and make sure, if you're going to swap difs this would be a good plan anyways.

    Rene 81 Jimmy,350,SM465/NP205,FF14 bolt,HD Dana 44,3.73's,4"susp.,35"Grabber MT's,body in progress
     
  9. k5beast

    k5beast Registered Member

    Joined:
    Aug 1, 2000
    Posts:
    8
    Likes Received:
    0
    Location:
    Northwest Florida
    Pull covers and count teeth on the pinion and ring gear, then divide the number of teeth on the ring by that on the pinion. This will give you the true ration of the axle.

    The Beast, feed me a Jeep!
    79 K5 project
     

Share This Page