Author Topic: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT  (Read 7194 times)

Offline jfkelley

  • Newbie
  • Posts: 81
  • Newbie
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #15 on: April 09, 2019, 12:15:38 PM »
I will go and look for a donor Drive Shaft ..When I’m looking for one should I look for an 700r4 Drive Shaft or TH350 ..Sorry for the questions I’m new to this but you Guys teaching me so much as I go along ..TIA !
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #16 on: April 09, 2019, 12:32:38 PM »
700r4 but same bed length as yours. only the 208 came behind them. so if you find a 1982+ 4x4 1500 it should be the one youre looking for
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline jfkelley

  • Newbie
  • Posts: 81
  • Newbie
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #17 on: April 09, 2019, 12:52:18 PM »
IRISH ..Shop said needs to be 4” shorter ..I’m going to try and do this myself like you said in the last post
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2526
  • Old Goof
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #18 on: April 09, 2019, 01:45:07 PM »
Really confusing!

Your original post said you were replacing a THD 350 with the same...

Where did the 700r enter the picture?  :o
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline jfkelley

  • Newbie
  • Posts: 81
  • Newbie
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #19 on: April 09, 2019, 02:03:32 PM »
I did replace the 1976 TH350 with an 85 K5 Chevy Blazer TH350 4x4 Transmission it has an K on the casing for I assume HD  ..I’m a newbie so I assumed it would be a drop in with no drive shaft mods
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #20 on: April 09, 2019, 02:47:12 PM »
Really confusing!

Your original post said you were replacing a THD 350 with the same...

Where did the 700r enter the picture?  :o

Thought we sent him on the wrong road lol. Glad you picked up on that I was feeling bad for missing the post about the 700r4 lol
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline jfkelley

  • Newbie
  • Posts: 81
  • Newbie
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #21 on: April 09, 2019, 03:15:01 PM »
So I’m good ? ..I can take the 4” inches out of the rear drive shaft myself and weld it back together correct ? Anyone have steps in shortening a drive shaft ?
« Last Edit: April 09, 2019, 04:44:19 PM by jfkelley »
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #22 on: April 09, 2019, 09:33:40 PM »
now when i say you could do it yourself its not something thats going to be real easy. you have to carefully cut the weld on the yoke where its welded to the driveshaft but you cant go too deep as theres a tapered end on the yoke that goes on the inside of the driveshaft.



now i would cut the side thats farthest away from the weight on the driveshaft itself. the 4" you cut off wont bee too much to effect the balance of the shaft but the less you cut off the better.
then comes to welding it. if i have to walk you through that im going to say not to weld it and take it somewhere or find a donor
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2526
  • Old Goof
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #23 on: April 10, 2019, 01:06:36 PM »
Can anyone weigh in on whether there is a difference between a 76 and 85 TH350 K model?

Did you remove the NP 203?

If not, why are you not having to adjust the front Drive Shaft? 
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #24 on: April 10, 2019, 01:30:56 PM »
think hes working on a new truck or a different setup
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline jfkelley

  • Newbie
  • Posts: 81
  • Newbie
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #25 on: April 10, 2019, 09:25:44 PM »
I replaced the original TH350 transmission in my 76 K10 , with an 85 TH350 K Series Transmission ..Sorry If I confused anyone
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #26 on: April 11, 2019, 01:09:09 AM »
where does the 700r4 come into play?
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline jfkelley

  • Newbie
  • Posts: 81
  • Newbie
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #27 on: April 11, 2019, 06:35:07 AM »
Irish I have no idea where the mention of 700r came from ? ..Guess I'm gonna have to go back and look over my previous post
« Last Edit: April 11, 2019, 08:51:29 AM by jfkelley »
1976 Chevrolet Scottsdale 4x4 ,K10 33” BF Goodrich All-Terrain .. in the middle of an LS swap LM7/4l60e/NP241C

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #28 on: April 11, 2019, 08:44:34 AM »
The saga began in a galaxy far, far away...

the yokes/t-cases will interchange but the th350 is about 2" shorter. unless its a different adapter/t-case. but they should have to shorten your shaft, which is easier (you could almost do it yourself with a cutoff wheel and welder) and cheaper sorry didnt think about this detail as being redundant as the 700r4 is pretty much the th350 but is longer due to the OD. the shop isnt lying but i would look for a driveshaft from a scrapyard or the donor the 700 came from.

 ;)
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: NEED ADVICE -1976 K10 / TH350 TRANSMISSION REPLACEMENT
« Reply #29 on: April 11, 2019, 11:47:19 AM »
yeah i think i goofed lol. think i mixed up a few post BUT if youre only working on the th350 you shouldnt need a new driveshaft.

as they say on the streets "my bad"
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes