GM Truck Club
THE PREMIER CHEVY TRUCK & SUV FORUM
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 7 of 7
  1. #1

    Default new gears necessary?

    I have the 3.73 posi rear end in my truck, and want to go from 33" tires to 35" tires at the next time they are due. Do I need to put new gears in the rear end? I have heard 4.10 or 4.56. Which would be better? Also, do I need to change the front differential gears as well, if possible?

    Thanks

    2007 Silverado LT Z71 4x4 Crew Cab
    Dark Metallic Blue

    Mods to come, just purchased on 10/31/09

    Go Pack Go!

  2. #2

    Default

    If your upgrading to 35's then you really should do the gears. And you will need to do front and rear otherwise it will just bind and break everything. I would probably do 4.56 because then if you ever want to put on tires bigger than 35's you don't need to worry about buying gears a second time.
    Dan
    1999 GMC Sierra 2500 350 vortec
    1967 Jeep M725 ambulance 230 tornado
    1990 Cherokee Limited- 3 inch lift on 33's
    ...and every one of em has issues

    If you have any questions or problems don't hesitate to send me or any other GMTC moderators a PM

  3. #3

    Default

    i would go with exactly what dan said... go 4.56's and you will need to do the front too
    PETE
    95 GMC Sierra 2500
    3" Body Lift, 33" Goodyear MTR's
    5.7L 350 TBI Edelbrock SDT Exhaust, Flowtech Headers, K&N Intake
    Sold :(
    1999 Jeep Cherokee, 3" Rustys lift, 33" BFG MT's, locked, armored: Rolled :(
    2000 Jeep Grand Cherokee Limited. K&N Intake, Custom Kolak Exhaust


    Contact this GMTC Moderator for any problems or questions you may have :great:

    Join the GMTC Facebook Group!!! Join Here

  4. #4
    Moderator

    dwill3015's Avatar
    Join Date
    Jan 2007
    Location
    Yacolt, Washington
    Posts
    4,338
    Blog Entries
    2

    Default

    X2-what he said!
    Darcy
    Washington State
    2006 Silverado 2500HD LT3 4X4 CC SB Duramax LBZ
    Tuff Country 6" lift, 35" Toyo M/T's on 20" Ultra Peacemaker wheels, Quadzilla Stealth2 programmer, Diamond Eye 5" cat-back exhaust, factory Special order color Yellow.

  5. #5
    Legend
    finalday7's Avatar
    Join Date
    Oct 2007
    Location
    Sayward, B.C Canada
    Posts
    1,358

    Default

    If 500-800 bucks isn't in the budget right now then you don't HAVE to change them right away. A change in the near future would be a safe bet.

    KRIS
    2007 GMC Sierra CrewCab 4.8L
    Tinted Windows, 20" Chrome MB Predators on 275/55/20 Copper AT's, GM Bed Rug, Speed Scene Chrome Grille, Putco Chrome Handles, Hypertech Max Energy Programmer, Magnaflow Muffler and many more mods to come.
    Former GM Vehicles:
    96 Chevy Camaro. My first car modded for a High School kid.

  6. #6

    Default

    $500-800 installed or just for the parts? Dad's a heavy equipment mechanic, and he has helped me with most of the stuff for the truck, but he has only done two rear ends in a pickup in his 30+ years as mechanic. Does it in cranes all the time, but very rarely a truck. How difficult is it to install the gears ourselves, or is it best to have a garage/shop do it for me?

    Thanks

  7. #7

    Default

    If dads a Heavy Eqpt. Mech. with a gear change or two under his belt he should be able to tackle this job with you. Plan for a whole day of work to do both diffs.
    Remove one gear set at a time, swap the gears, trial fit and shim as required. Probably want to replace the axle seals at the same time (cheap insurance). When purchasing the gears buy a master install kit (axle seals wont be included and will need to be purchased separately), and a gallon of your favorite diff. lube.
    I'd recommend 4.56's for 35" tires.
    $500 to $800 sounds like parts only for both diffs, install with parts is usually closer to $1100-$1200

Similar Threads

  1. 3.73 Gears
    By Restlessone in forum GM Powertrain
    Replies: 10
    Last: 08-31-2009, 01:40 PM
  2. looking at new gears?
    By 5speedsilverado in forum GM Powertrain
    Replies: 10
    Last: 07-02-2009, 03:16 PM
  3. Gears
    By larryleeUSN in forum Lifted & Offroad Suspension
    Replies: 17
    Last: 06-23-2009, 10:22 AM
  4. Gears!?
    By VolsFan21 in forum GM Powertrain
    Replies: 4
    Last: 06-18-2009, 07:48 AM
  5. Can I drop 3.08 gears in a 1998 2wd Suburban-3.4 gears?
    By phoebeisis in forum GM Powertrain
    Replies: 6
    Last: 12-14-2007, 11:12 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •