How to Choose the Right Axle Ratio for Your Pickup Truck | Member, Administrator, Moderator Posts: 10,315
edited October 2017 in Editorial
How to Choose the Right Axle Ratio for Your Pickup Truck |

If you're buying a pickup and you plan on towing or hauling heavy loads, here's how to choose the right axle ratio.

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  • unomavunomav Member Posts: 1
    Thanks for the helpful info on axle ratios.
  • jpost105jpost105 Member Posts: 1
    Great article Thanks for the education.
  • wannabgearheadwannabgearhead Member Posts: 1
    Very informative.
  • ottolt96ottolt96 Member Posts: 1
    the drive-axle ratio is a comparison of the number of gear teeth on the ring gear of the rear axle and the pinion gear on the driveshaft. For example, a 4.11:1 ratio means there are 4.11 teeth on the axle's ring gear for each tooth on the driveshaft's pinion gear, not the turns of the drive shaft to turns of the wheel as stated above
  • thecardoc3thecardoc3 Member Posts: 5,666
    edited October 2017
    @ottolt96 Ah, no. That's not how it works and the article is correct. Here is another explanation that goes a little deeper into the subject.

    From the linked article....

    When you hear people refer to numbers like 3.08, 3.73, or 4.10, they’re talking about the ratio of the ring-and-pinion gears in the rear axle—hence, the numbers are more accurately 3.08:1, 3.73:1, or 4.10:1. The ratio is the number of teeth on the driven gear (ring) divided by the number of teeth on the drive gear (pinion). So, if the ring gear has 37 teeth and the pinion has 9 teeth, the ratio is 4.11:1. That also means that for every one turn of the ring gear, the pinion will turn 4.11 times.

  • rcbisymanrcbisyman Member Posts: 1
    So if I want to tow something that is 12,000 GCWR I should have 4.10 axle ratio towing long distances on a highway
  • Heart_n_Guts77Heart_n_Guts77 Member Posts: 1
    @rcbisyman I'm pretty sure that will depend on what truck you have too. 12k will be very easy for a ford f-350 with a 3.55 axel but might not be that easy for a f-250. So you need to take that in consideration.
  • DragnRodsDragnRods Member Posts: 1
    Like the article said, engine, tranny & tire size also has to be taken into account. My truck is a 78 Power Wagon. 440 high performance bored out to a 475, 727, np205, 3.21:1 ratio, & 31x10.5x15 tires. So only taking into account the gear ratio, my truck should be pretty damn fast & shouldn't be able to haul much for a load, right? Wrong, a 727 is only a 3 speed tranny & is designed to shift into 3rd at lower rpms, so my top speed us around 60mph & I can haul anything u want & have NEVER been stuck!!!
  • DaverceeDavercee Member Posts: 101
    Very informative article, nonetheless. Thank you very much!
  • NCJTENCJTE Member Posts: 1
    So if I have an F-250 with a 3.73 axle ratio, Ford says I can max tow 12500. However if i had the 4.30 ratio, I could tow 15K. My question is this: If I got a toy hauler trailer (fifth wheel style) that weighed 13500k, can I tow it with my truck providing I don't go beyond the payload capacity for the truck bed?
  • thecardoc3thecardoc3 Member Posts: 5,666
    Funny typo I believe, but no you would not be able to tow "13500K". Dry hitch weight and draw weight considerations are important to match to your truck. The hitch weight is usually 20% of the draw weight which puts about 2700lbs in the bed.

    According to this site . You would have plenty of payload capacity. The draw weight slightly exceeds the specs and while the truck would pull it, you might experience some premature wear or an issue when dealing with hills. There would be some owners who would "get away with" a slight overload like this depending on exactly how and where this would be used.
  • Mr_85truckMr_85truck Member Posts: 1
    So I have a 1985 F-150 and I'm considering putting 3.27 rear gears in it with 31 inch tires and I'm wondering if that ratio is too high. I have a 3.55 ratio now and I'm not going to have overdrive anymore with the transmission going in so I'm wondering if going to a higher rear gear is better.
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