4L80E / NP205 combo - could I use a LONG 32-spline input shaft?

Discussion in 'The Garage' started by grojguy, Jun 17, 2003.

  1. grojguy

    grojguy Newbie

    Jun 17, 2003
    Likes Received:
    Portland, OR
    I have an older-style "figure-eight" bolt-pattern NP205 (from TH400 application, w/ short 32-spline input shaft & 4" t-case adaptor) which I am trying to mate to a 4L80E. There are two incompatibilities:

    * tranny to adaptor indexing - 4l80E index is slightly different diameter than TH400 was, so t-case adaptor needs slight machining...can-do, no big deal.

    * output to input shaft lengths - short 32-spline input shaft stickout=1.25" + 4" adaptor + 4L80E stickout = 3" gives only 0.25" engagement, = no good.

    After considering a bunch of options including custom adaptors, longer tranny output shafts, etc, it seems to me that the easiest option is to use a LONG 32-spline NP205 input shaft. The one catch is, I then have to trim approx. 0.5" off the end of the 4L80E output shaft so it does not bottom out in the long NP205 input shaft.

    Soooooo, since it seems that quite a few people are getting rid of their LONG 32-spline NP205 input shafts, to convert to the short version for the Doubler, I was thinking maybe someone might have a long input shaft laying around, needing a home?


Share This Page