Towing with 6.2 & 3.42 gear ratio

Discussion in 'Towing & Trailer Tech' started by Toytech6466, Jan 1, 2014.

  1. Toytech6466

    Toytech6466 New Member

    Hey all
    I am curious what you are towing with your 1/2 tons with the 6.2 and 3.42 gear ratio. How does it do in the mountains? I know getting the 3.73 will be better but I am only towing about 6 to 8 times a year and only 1 or 2 times will be up into the Sierras. I will be towing a 23 foot toy hauler that will be max weight of 8,000 pounds, most of the time between 6,500 to 7,000.

    Thanks in advance
  2. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    What year/model is your truck? For the 1991 year which is pretty representative of the 90s bodystyle, the 6.2L diesel with 3.42 gears has a max front axle weight rating of 3400 and rear axle rating of 3968, and gross combination vehicle weight (GCVWR) of 10,000 pounds. Considering the truck weighs in at around 6000 pounds, that only gives you 4000 pounds of capacity. That said, the brakes are probably not strong enough to adequately stop that, and you will certainly need a weight distributing hitch. The engine and transmission are probably adequate on flat land, but not the mountains because of the low gear ratio. You'd need to ramp up to 4.10s or even 4.56s to drag 8000 pounds up the mountain.
  3. 08_rado_rocker

    08_rado_rocker Member 2 Years 500 Posts

    He was asking about 1/2ton trucks... So I'm pretty sure it doesn't have a diesel setup no matter the year/model haha:great:. That being said, I've never hauled with 3.42 ratio before but if it's a newer truck, your transmission is going to play a huge part with your concerns. Hopefully your truck has a 6l80 in it, but even so with that kind of weight around hills, the 3.42 gears are going to cause your truck some strain and I'd recommend the 3.73 upgrade.

    Before I took all the trailering stuff off of and lowered my 08 he pulled 8K around Texas hill country with no problems (5.3 4l60 3.73 and set up as it says in signature)
  4. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Your not giving us much info to enable a proper answer; but, here is my 2 cents.

    I have the 3.42 and the 5.3 I also have the tow/haul feature and a 6 speed tranny.

    My advice: you have either the 4 speed, or the 6 speed tranny, just drop down a gear for the 4speed, or 2 gears for the 6speed and you will be fine. have a transmission fluid cooler.
  5. the phantom

    the phantom Epic Member 5+ Years ROTM Winner 1000 Posts

    And you have the stock size tires.. putting larger diameter tires on the truck significantly changes the ratio.. Any larger than stock and you wont be happy even with the 6 speed. It will constantly hunt for gears and wont be good for the tranny regardless of which tranny you have.
  6. lenb

    lenb New Member

    i just traded my 11 ltz sub. in, regretfully. it had 5.3, 6 spd,3:42 gears,also 275/60/20 toyo 2's. i tow my 27' toyhauler @7700 # dry, after adding rzr s,850 scrambler, 105 gals. of water and gear,beer, and other neccessaries?, i am pushing 10000#s. it handles well w/equalizer brand hitch. moves very good,but @ 70- 75 mph mpg is 5.5-6.5.@ 65 will push 7-7.5. i have gm air suspension, it screwed up rear sensors but rear stays pumped up. shifting is much better w/6spd. my 08 yukon prior to this w/4spd.,5.3, &3:73 gears had better mpg, 7.5-9 ,but trans searched and rpm went to hi on grades (upper mi.,@western pa.) yukon was same setup, minus air susp. i installed air lift @rear only w/ manual inflation much better. well now, 1 week ago, i now have a dbl/cb 2014, ltz w/z71,trlr pkg. not max pkg,and 6.2.. love it, awesome truck, also put toyos back on. i will tow soon, hope hp/torq, w/3:42s improve. i could'nt find max pkg /w6.2...besides z71 cannot have max pkg......p.s. subs. had no issues w/overheating. as of 71,ooomiles..
  7. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Souunds like a nice truck.

    Did you have any oil consumption problems with the '11 ?

    I know when towing, the AFM would never (hadly ever) shift to 4 cylinders, wondering if that made any differance with the AFM/oil problem. Or, maybe the '11 trucks were fixed.
    Last edited: Oct 29, 2014
  8. dobey

    dobey Epic Member 5+ Years 500 Posts

    I've not had any AFM/oil problems with my '09, and it's at ~52K miles now. I bought it used, and it was a fleet vehicle (presumably a rental company owned it) previously. The '11 should have had VVT as well though, which should have smoothed the torque curve, and might actually result in AFM being used more often, though when towing AFM will almost never be active, unless coasting downhill or something similar.

    I also find it hard to believe that whether it is being activated or not has any bearing on the lifespan of the lifters. They are only safely usable for a cam with max of about 0.525" lift at the valve with stock rockers, though. And only to about 6200 RPM. Exceeding either or both of those risks severe mechanical damage.

    Do you have a link to a tech bulletin or something that describes the exact mechanical failure issues with the AFM, for engines that have had such failures? I'd like to see what the actual cause is, rather than just trying to sift through all the malaise of people placing generalized blame on the system, without understanding the problem.
  9. lenb

    lenb New Member

    never had any oil consumption uses at all . v4/v8 modes only switch up in ideal rolling conditions.(like down hill or w/ a tailwind lol). that was true for both 5.3s in 08 and11. i keep oil changed regularily and use mobil 1..p.s. the 2014 5.3, is now 355 hp., and max trlr pkg (only way to get 3:73 gears in a 1500 model) is rated to tow 11000 #s.
  10. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Ok, good to know, thanks for the info.

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