Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

will my 6.2 be happy with 3.73 gears??

Discussion in '1982-Present GM Diesel' started by 84CUCV, Apr 21, 2007.

  1. 84CUCV

    84CUCV 3/4 ton status Premium Member

    Joined:
    Jul 1, 2002
    Posts:
    7,115
    Likes Received:
    2
    Location:
    NJ for now
    it a 6.2 th400. Still not to sure how to figure out the rpms. thanks for the help
     
  2. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    Well it depends what size tires you will run but with the th400 you can go taller gears so 3.73 should get your RPM's lower for better MPG.
    That is assuming you had 4.56 beore since you have a M1008 CUCV right?
    Or did you have a M1009 with 3.08?
     
  3. 84CUCV

    84CUCV 3/4 ton status Premium Member

    Joined:
    Jul 1, 2002
    Posts:
    7,115
    Likes Received:
    2
    Location:
    NJ for now
    i have both cucvs. i am taking the axles from a m1010 and taking the 3.73 3/4 ton and putting them into the M1010 and going to sell it i hope. will the 6.2 be able to hit 70mph ok? thanks
     
  4. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,178
    Likes Received:
    1,387
    Location:
    E-town baby!
    Assuming 31" tires it'll be doing about 2850 rpm at 70 mph. Not great, but doable. 2650 rpm if on 33's...

    Rene
     
  5. 84CUCV

    84CUCV 3/4 ton status Premium Member

    Joined:
    Jul 1, 2002
    Posts:
    7,115
    Likes Received:
    2
    Location:
    NJ for now
    I have some 33s. thanks a lot
     
  6. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

    Joined:
    Jul 23, 2000
    Posts:
    36,178
    Likes Received:
    1,387
    Location:
    E-town baby!
    No problem.

    Speed x gear ratio x 336 divided by tire diameter will get you very close.

    Rene
     
  7. 84CUCV

    84CUCV 3/4 ton status Premium Member

    Joined:
    Jul 1, 2002
    Posts:
    7,115
    Likes Received:
    2
    Location:
    NJ for now
    thanks rene
     
  8. 4x4_76

    4x4_76 1/2 ton status

    Joined:
    Jul 22, 2001
    Posts:
    628
    Likes Received:
    0
    Location:
    Ylämaa, Finland
    There's one calculator: http://www.phnet.fi/public/mika.jussilainen/laskuri2.htm

    I was woried that I'm killing the engine with 4 speed box (I may have found SM465 dirt cheap) with 33" tires and 4.56's, but after some calculating rpm's are around 2320 when going 50 mph (that's as fast as I can go legally with 'Burban). Someday I get NV4500, but at least for now they are really rare in here.
     
  9. grimjaw

    grimjaw 1/2 ton status

    Joined:
    Jun 19, 2004
    Posts:
    944
    Likes Received:
    0
    Location:
    Seymour, TN
  10. CumminsChick

    CumminsChick 1/2 ton status

    Joined:
    Jan 19, 2007
    Posts:
    127
    Likes Received:
    0
    Location:
    Lexington KY
    mine will hit 70 but i have 456s, came stock with 3.73 (no lift) and she'd hit 70 on a good day.
     
  11. 84CUCV

    84CUCV 3/4 ton status Premium Member

    Joined:
    Jul 1, 2002
    Posts:
    7,115
    Likes Received:
    2
    Location:
    NJ for now
    ok thanks
     

Share This Page