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.

NP208 cases--interchangability??

Discussion in 'The Garage' started by diesel4me, Oct 29, 2004.

  1. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,540
    Likes Received:
    930
    Location:
    Massachussetts
    I was junkyard shopping again yesterday--since I think my NP208 case in my diesel is stuck in 4wd,I thought it might be wise to look for a spare in case mine craps out this winter when plowing,before the snow comes and makes removing anything at the boneyard a real hassle.I saw at least 20 trucks with either a NP208 or NP241,but most of them were attached to a 700R4 overdrive,or a SM465--mine has a TH400--I know the splines on a 700R4 are smaller,but what about the 4 speed ones???--will one from a 4 speed fit the TH400??--or can I change the input shaft??(last resort--I dont like playing with needle bearings!).Or should I get an adaptor for the 205 I will be pulling from my 74 K20??(probably expensive and hard to find right??plus mine is a TH350 version--wont work due to the smaller splines like the 700R4 right??)Can someone clue me in on this?? /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/ears.gif /forums/images/graemlins/ears.gif
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

    Joined:
    Sep 1, 2001
    Posts:
    8,972
    Likes Received:
    0
    Location:
    Peoria, AZ
    SM465 = TH400 = 32 spline
    TH350 = 700R4 = 27 spline

    You can use the TH400 cases behind a SM465, you will have to swap input gears to run a case from behind a TH350 or 700R4.

    A 241 from behind the 465 or 400 will work too.

    Harley
     
  3. pauly383

    pauly383 Daddy383 Staff Member Moderator

    Joined:
    Jul 22, 2001
    Posts:
    16,217
    Likes Received:
    1
    Location:
    Mesa , Arizona USA
    In 1980's GM's with passenger side front outputs , they will all interchange in the case , the difference is in the input shaft , 27 spline for th350 and th700r4 , 32 spline for th400 and sm465 . So to run the different cases in different applications will require swapping the input shafts , which isn't too hard /forums/images/graemlins/k5.gif /forums/images/graemlins/k5.gif
     
  4. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,540
    Likes Received:
    930
    Location:
    Massachussetts
    Thanks for the info!!.I might go back and see how much they want for the whole 4 speed setup--I might be able to get it for about 200 bucks including the case--they are squashing everything like crazy here--over 4 acres of trucks like mine at this yard have gone to the crusher in the past 3 weeks--including an 82 K10 with a 6.2 and a SM465 and NP241 t-case--they offered it to me for 500 bucks as is,whole truck--but no title and they bashed it all in with the loader--two days later I went back,and it was at the bottom of a pile of crushed cars and trucks--guy said they can get almost that much for scrapping it--so I lost out! /forums/images/graemlins/doah.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/angryfire.gif /forums/images/graemlins/screwy.gif
     

Share This Page