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Discussion in 'Chevy Trucks' started by RICHARDM, Nov 25, 2001.


    RICHARDM Junior Member
    Messages: 8

    how do you determine the axle ratio of a vehicle. I have a 1986 Suburban. what ratio is a good one to be used for doing a lot of towing with. thanx
  2. Alan

    Alan PlowSite.com Addict
    Messages: 1,393

    If the sticker is still on the glove box you can go to your Chevy dealer and they can identify the axle code and from that the ratio.

    Other than that, jack up the rear, mark the driveshaft and wheels and turn the driveshaft, count the turns needed to rotate the wheels one full turn. The numbers should be roughly 3.5, 3.75 or 4 to one. Those would equate to 3.4?, 3.73 or 4.10 ratios. Those are the most common, I'm not exactly sure just what the 3.4? is,, but I think it's either 3.42 or 3.48.

    3.73 will do fine for towing, even 3.4? will be ok with lighter loads. 4.10 will give you power but poor fuel economy. As a rule, with everything else equal, you get a higher tow capacity as the axle ratio gets lower
  3. thelawnguy

    thelawnguy PlowSite.com Addict
    Messages: 1,011

    Check the option sticker either under the hood or in the glove box, look for 3 letter code starting with "G", GH0 is 3.54, GT4 is 3.73, post the specific code and I can tell you what came from the factory with the truck.
  4. 75

    75 PlowSite.com Addict
    Messages: 1,382

    IMO, 3.73 is a good all-around ratio. There are many factors to consider, such as weight of vehicle, output of engine, and what sort of towing you're doing.

    My own truck is heavy, has a 350 engine and I get into some winching/pulling etc with it, but little highway towing. So 4.10 is ideal for my purposes - although when I do pull on the highway the 'ol truck likes it's fuel!

    If your truck is lighter (mine comes in well over 7,000#) has a fair amount of power (big-block or diesel) and you'll be towing mainly on the open highway, 3.4(?) can work OK.

    3.73 is a good "compromise".