So lets talk about TH400 output shafts

Discussion in 'The Garage' started by afroman006, Feb 22, 2006.

  1. afroman006

    afroman006 1/2 ton status

    Aug 21, 2002
    Likes Received:
    College Station & Kingsville, Texas
    I need to know what length output shafts came with what transfer cases and adapters for TH400s. Off the top of my head, I know GM used the following combos

    Th400/ figure 8 adapter/ short 32 spline input 205
    Th400/ 6 bolt round adapter/ long 32 spline input 205
    TH400/ ? adapter/ 32 spline NP208
    TH400/ ? adapter/ 32 spline NP241
    TH400/ expensive adapter/ 32 spline NP203

    What I dont know is the output shaft length of the trannies. Which of these will interchange? I believe NP208s and 241s use the same adapter and tranny output length but I'm not positive. What about other case and adapter interchangeability?

    Specifically, I want to know if a 241 will bolt to a 6 bolt adapter/ long 32 spline input NP205 version TH400, maybe even with the same adapter?
  2. jekbrown

    jekbrown I am CK5 Premium Member GMOTM Winner Author

    May 19, 2001
    Likes Received:
    Vancouver, WA, USA
    the th400 has at least 5 different output shafts...

    1) 15" (overall) 27 spline 2wd shaft
    2) 13" 10 spline 4x4 shaft
    3) 9.25" 32 spline 4x4 shaft
    4) 2.5" (spline length, my manual doesn't show an overall length) 32 spline 4x4
    5) 1.25" (again, spline length) 32 spline 4x4

    #5 is definitely the np203 version. It hardly sticks out of the rear of the trans at all... don't need to worry about the 10 spline or 27 spline versions. That leaves two shafts. From what I recall, the shorter (#4) one is for the np205... and the longer one (#3) is for the 208 etc. Could be wrong... but my th400 manual doesn't think so. :)

  3. hack500

    hack500 1/2 ton status

    Sep 16, 2005
    Likes Received:
    Templeton, Ma

    The 6 1/2 inch shaft sticks out past the case 2 3/8 inches. (np208/?241?)
    The 5 1/2 inch shaft sticks out past the case 1 3/8 inches. (np203)

    Some TH400 4WD transmissions have 2WD output shafts that stick out 4 3/4 inches past the case. (np205/short tail 2wd)

    the above info is from

Share This Page