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37's with 4.10 gears???

Discussion in 'Lifted & Offroad Suspension' started by infantry_18, Aug 10, 2012.

  1. infantry_18

    infantry_18 New Member

    hey guys i have 08 scsb 5.3 z71 4x4 with 4.10s stock. im puttin on some 37's and wont be able to regear for at least a yr.....how do you think it will handle and mpg's? also truck will have cai, tbs, and tuned for economy/towing with the known gear and tire ratio....to help with shifting and wat not. wat yall think i'll be ok to hold out until i can regear??
  2. SurrealOne

    SurrealOne Former Member 1000 Posts 100 Posts

    I think it'll be atrocious to get going from a stop and on mild inclines you'll downshift (i.e. drop out of overdrive at highway speeds). I'm running 4.56's for my 34's (I'd run the same for 35's) and it's near-stock performance (I originally had 3.73's) with a slight bias for power. If I were running 37's I'd run no less than 4.88's, gear-wise...

    A year with those gears is a long, long time. You can do it, but it's going to be extra wear on your tranny ESPECIALLY when towing ... and you'll take a mpg hit when getting off the line as well as when on a mild incline at highway speed due to the downshifting you'd not otherwise do.
  3. infantry_18

    infantry_18 New Member

    i want to re-gear but i have to drive 5 hrs to atlanta leave my truck there for 2 days then drive back roads and stop for 30 mins every 25-50 miles until i hit 150 miles oh and its gonna be about 1600 installed out the door. plus the gas for all this will just be ridiculous u kno.....i really wanna find a shop that will install gears closer to base but nothing pops-up on google so idk
  4. SurrealOne

    SurrealOne Former Member 1000 Posts 100 Posts

    1600 is about right for a 4wd since you're doing front and rear (with the front being the bigger time suck/pain of the two). Two days, however, is ridiculous. There's no reason they can't get your truck in the morning and have it back to you by the end of the same day if they know what they're doing.

    My break-in period was akin to what you describe ... i.e. 500 miles of running for only 25-50 miles before one lets the gears cool down ... and after 500 miles the diff fluid had to be changed. Failure to adhere to these requirements would result in loss of warranty coverage on the parts and labor.

    I suppose I was lucky, as ECGS (East Coast Gear Supply) is just down the road from me.
  5. Burden33

    Burden33 New Member 100 Posts

    if your only doing highway driving it might be ok nor a year aslong as your not drivng with a real heavy foot all the time but saying all that it might not hold up. im running 35's on my 3.73 for 9 months now and i havnt had a prioblem yet.
  6. tbplus10

    tbplus10 Super Moderator Staff Member Platinum Contributor 1000 Posts 100 Posts

    First off I think you'll be extremely dissappointed with your truck after you put that large of a tire without regearing. No amount of upgrades short of a supercharger will help and even that would be a bandaid.
    next how long do you expect the front diff and Cv's to last with this size tire? Long would not be a word id use pertaining to its life.
    and finally are you going to do anything about upgrading braking?
    in a nutshell if you put this size tire on your truck without properly upgrading other systems expect to spend a lot more money on repairs.
  7. SurrealOne

    SurrealOne Former Member 1000 Posts 100 Posts

    37's for highway driving? I know of no one who puts 37's on a vehicle for .... highway driving. LOL!
  8. Burden33

    Burden33 New Member 100 Posts

    good point i never thought about that but i will be when i go out to get my new gears put on. Thats if i goes that big. but tbplus has a point your better off going with 35's
  9. Ridyn

    Ridyn New Member 100 Posts

    This is exactly why i'm not going to be doing anything to my truck until I get back from all my training 7 1/2 months from now. It'll give me time to save money and I will also be able to do it all at once, lift kit, bigger tires, re gear, and more.
  10. aloxdaddy99

    aloxdaddy99 New Member 1000 Posts 100 Posts

    All the above is true. The other issue that tbplus said was about repairs. I would worry about the strength of the axle's. Adding a tire that large is adding a lot of stress to them. It might be fine if the only offroading you are doing is in a mall parking lot but if you are going to be wheeling that thing I am not sure how long they will last.

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