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.

Tranny swap TH400 to SM465

Discussion in 'The Garage' started by 53chevy, Feb 12, 2007.

  1. 53chevy

    53chevy 1/2 ton status Premium Member

    Joined:
    Dec 29, 2004
    Posts:
    369
    Likes Received:
    7
    Location:
    pitcairn
    I have a 1 ton 350 with a TH400, i really dont have any love for this tranny, it gose to a NP205. I belive its a 10 spline, will that fit right up to the engine and T_box?
     
  2. twoslo4five0

    twoslo4five0 3/4 ton status Premium Member GMOTM Winner

    Joined:
    Oct 5, 2006
    Posts:
    6,615
    Likes Received:
    71
    Location:
    Living in a dump, VA
    you mean the 465 is 10 spine???if you have a 465 10 spline and a 205 10 spline all you will need is a crossmember,adapter,and all the other stuff...
     
  3. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

    Joined:
    Jun 23, 2000
    Posts:
    7,924
    Likes Received:
    335
    Location:
    Fort McMurray, Alberta
    I did the same swap, took me an afternoon to do after collecting all my parts.

    I'd suggest going with a hydro clutch setup, makes retrofitting a real breeze :)
     
  4. 53chevy

    53chevy 1/2 ton status Premium Member

    Joined:
    Dec 29, 2004
    Posts:
    369
    Likes Received:
    7
    Location:
    pitcairn
    how do i check the splines?
     
  5. 53chevy

    53chevy 1/2 ton status Premium Member

    Joined:
    Dec 29, 2004
    Posts:
    369
    Likes Received:
    7
    Location:
    pitcairn
    Can you use 2 trannies? The TH 400 to the SM465? to the 205
     
  6. Jishory

    Jishory 1/2 ton status

    Joined:
    Jan 8, 2002
    Posts:
    1,367
    Likes Received:
    0
    Location:
    Palmdale, CA

    damn, AN AFTERNOON? took me like a damn month
     
  7. twoslo4five0

    twoslo4five0 3/4 ton status Premium Member GMOTM Winner

    Joined:
    Oct 5, 2006
    Posts:
    6,615
    Likes Received:
    71
    Location:
    Living in a dump, VA
  8. Russell

    Russell LB7 Tahoe Status Premium Member GMOTM Winner

    Joined:
    Jun 23, 2000
    Posts:
    7,924
    Likes Received:
    335
    Location:
    Fort McMurray, Alberta
    Don't feel bad, when I first started with these trucks, it took me 5 months to diagnose, and repair a blown intake gasket :doah:

    Your TH400 / 205 combo will probally be a 32 spline setup. The SM465 also can be had in a 32 spline setup, but was only available as such after 83ish...

    Prior to then, it was a 10 spline setup. The 32 spline is a more desireable combo, as the 10 spline shafts wear out, and eventually can strip out, or break the adapter sleeve... 10 spline setups are very common, and can be bought for like 250 - 300 bucks, with driveshafts and brackets.

    As I mentioned earlier, I would highly suggest a hydro clutch, even if you use a mechanical bellhousing with a Novac hydro kit. Drilling holes for linkages is very time consuming, while the hydro pedals pretty much bolt straight in.

    When I installed my SM465 / 205, I just unbolted the cab hump, dropped the 2wd TH400 I had in there out, then bolted on the bellhousing / clutch stuff, slipped the new transmission in, and rested it down on the new crossmember by the adapter. I then went to work hooking up the clutch (drilled a 1.5" hole in the firewall for the master cylinder, then two holes for the supports).

    Had a buddy over, so we wrestled the 205 up and in, bolted it up, hooked up the driveshafts, then bolted a new tranny hump on. Hooked up the reverse switch, and speedo cable, then hit the road!
     
  9. RootBreaker

    RootBreaker 3/4 ton status Premium Member

    Joined:
    Nov 29, 2001
    Posts:
    5,117
    Likes Received:
    173
    Location:
    Williamstown, NJ USA
    I second the swap expecially to the hydraulic clutch...

    I had a turbo 400 with b&m shiftkit.. would rip your head off... I then got to drive a truck with a smc... boy let me tell you what.... the power control was so worth it...

    i actually found a truck... 1978 chevy 3/4 ton... 350/smc465/np205/d44/14bff/4.56's factory....
    $500 and ran.... i took it and swapped everything over...

    the only thing I didnt like was the mech clutch.. I went to a hyro setup off of a 1985 fullsize jimmy i bought for $100... and will never go back to...

    1. a automatic
    2. a non hydro clutch setup.....

    it is so nice..

    it is funny too that i did my swap in 1989 (auto to manual) and there was no internet or any tech docs.. my father is a mechanic and said it was easy.. we did it in 1 weekend...

    wanna see 2 trucks apart in a yard... :haha:

    [​IMG]

    [​IMG]

    there she is ... the beauty...
    [​IMG]
     
  10. blazin_blazer

    blazin_blazer 1/2 ton status

    Joined:
    Aug 2, 2005
    Posts:
    4,043
    Likes Received:
    0
    Location:
    central arkansas
  11. geddesj

    geddesj Registered Member

    Joined:
    Dec 28, 2009
    Posts:
    15
    Likes Received:
    0
    Location:
    so. cal
    good ol fashion red neck tech. i love it

    it is funny too that i did my swap in 1989 (auto to manual) and there was no internet or any tech docs.. my father is a mechanic and said it was easy.. we did it in 1 weekend...

    wanna see 2 trucks apart in a yard... :haha:
     
  12. RootBreaker

    RootBreaker 3/4 ton status Premium Member

    Joined:
    Nov 29, 2001
    Posts:
    5,117
    Likes Received:
    173
    Location:
    Williamstown, NJ USA

    are you my twin?
    1988 i did my swap.. same thing.. no internet... no tech docs...
    i took a auto truck and a manual truck.. swapped my auto cab to the manual frame.... then swapped over the pedal assembly and everything.. my father is a mechanic too.. damn good one.. if it ever ran.. he can get it to run again...


    p.s. my truck was made from about 8 in a junkyard....we know the guy and i got a good deal.... and yes that is me @17 with a mullet!!!

    2 trucks totally apart
    [​IMG]

    my manual frame which this is the truck that is still with me.. well most of the parts....
    [​IMG]

    [​IMG]

    blue bed side
    [​IMG]

    grey bed side and my mullet shot
    [​IMG]
     
  13. twojoints444

    twojoints444 Registered Member

    Joined:
    Sep 14, 2009
    Posts:
    95
    Likes Received:
    0
    Location:
    B.C. Canada
    I did a 700r4 to 465 recently took me FOREVER to find all the parts cuz I was stupids and didn't just buy a parts truck. After sum help from some good people(Russell) I got er did and now I got one hell of a truck. Wish she had the 5th gear sometimes but I think my gear ratio will calm down once I put my 38s on as I'm only running 31s now with 410 gears and no tach or spedo to tell me what's go on hahaha
     
  14. 79bonanza

    79bonanza 1/2 ton status Premium Member

    Joined:
    Mar 31, 2010
    Posts:
    1,665
    Likes Received:
    274
    Location:
    Georgetown, Kentucky
    im not tryin to brag but when i worked at the gm dealership we brought a 2003ish or so 2500 with the alison in it and swaped a 5 speed into it in about three hours, clutch, trans crossmember d-shafts flywheel and shifter junk in the floor boards but we were both really familiar with these trucks and we hade all the parts on hand waitin for us. started at 8 am when we got there and drove it to lunch haha then took the rest of the day off for a break haha
     
  15. twojoints444

    twojoints444 Registered Member

    Joined:
    Sep 14, 2009
    Posts:
    95
    Likes Received:
    0
    Location:
    B.C. Canada
    And that poor guy probably got charged for 2 day labour LOL u sacs hahaha
     
  16. 79bonanza

    79bonanza 1/2 ton status Premium Member

    Joined:
    Mar 31, 2010
    Posts:
    1,665
    Likes Received:
    274
    Location:
    Georgetown, Kentucky
    hahah nah it was the guy i worked withs truck lol, we took the morning off so we didnt get inturupted while swaping everything out haha got a free lunch for my labor, always worth it haha
     

Share This Page