Author Topic: Transmission and transfer case ???  (Read 2456 times)

Offline BradRuiz 83

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Transmission and transfer case ???
« on: November 18, 2019, 10:21:39 AM »
does anyone know what kind of transmission and transfer case a 1980 k10 4x4 chevy came out with... anything helps

Online Shifty

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Re: Transmission and transfer case ???
« Reply #1 on: November 18, 2019, 12:16:42 PM »
Probably a TH350, possibly a TH400, and it should be a New Process 205 transfer case.
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

Offline SilverMiner

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Re: Transmission and transfer case ???
« Reply #2 on: November 18, 2019, 07:20:07 PM »
does anyone know what kind of transmission and transfer case a 1980 k10 4x4 chevy came out with... anything helps

When it comes to 1980, the General made the transfer case mystery easy: <Oprah Voice> You get an NP205, you get an NP205, and YOU get an NP205! </Oprah Voice>. The 203 full time was forbidden, and everybody got the best transfer case.

But when it comes to the trans, things get more dicey. I just looked up things on the https://www.gmheritagecenter.com/gm-heritage-archive/vehicle-information-kits.html which is an invaluable resource, but I forgot all the 3-speed autos got the MX1 RPO. To the best of my knowledge, no 1/2 ton 10-series trucks in 1980 got the desirable TH400 because previously (74 to 77? not sure) the TH400 was only attached to the big block 454 in 2wd which was not available in 80. I'd bet money if your K10 is 100% original it has the much maligned TH350C and not a standard TH350 because that's the only transmission offered from the dealer.

BUT...  But.... what are the odds your nearly 40 year old vehicle is still stock? How many previous owners have made modifications? What you need to do is crawl under the rig and take a good look at the pan and compare its shape to the many trans identifying images here on the internet. The shape of the pan will tell you conclusively whether or not it is a 400 or 350, but to identify if it is a 350C look for an electrical connection on the driver's side just above the mid-pan point.

You can Google what issues the TH350C was famous for, but don't despair. If it has made it this long, you're probably fine.

Good luck!

Offline JohnnyPopper

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Re: Transmission and transfer case ???
« Reply #3 on: November 18, 2019, 09:57:21 PM »
Post pics of both the trans and NP and you will get the answers you seek...!
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

Online Shifty

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Re: Transmission and transfer case ???
« Reply #4 on: November 19, 2019, 08:45:02 AM »
BTW: A TH350 will be square with a corner cut off at an angle, whereas a TH400 is (roughly) Texas-shaped.
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

Offline JohnnyPopper

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Re: Transmission and transfer case ???
« Reply #5 on: November 19, 2019, 09:58:14 AM »
Shifty is referring to the shape of the oil pan.

Texas, never thought of that!  ;)
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 BradRuiz 83

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Re: Transmission and transfer case ???
« Reply #6 on: November 19, 2019, 02:58:31 PM »
Do you think a 700R4 would be best...

Offline JohnnyPopper

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Re: Transmission and transfer case ???
« Reply #7 on: November 19, 2019, 05:26:26 PM »
I've heard good and bad things about that transmission.

I would love the OverDrive in my K10.  ::)

I think it will depend on how hard you are going to tax it, that's where I have heard they don't hold up.

Also, there is rumor that certain years are better than other in terms of quality.

There is also the electronic control issue, but I understand there are aftermarket systems to overcome that.

There is an outfit that offers to do the complete install for 1800.00, trans included.

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

Online Shifty

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Re: Transmission and transfer case ???
« Reply #8 on: November 19, 2019, 05:35:03 PM »
Maybe shop for a used Gear Vendor....
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)

Offline BradRuiz 83

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Re: Transmission and transfer case ???
« Reply #9 on: November 19, 2019, 09:10:49 PM »
Thanks a lot man... really appreciate it

Offline VileZambonie

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Re: Transmission and transfer case ???
« Reply #10 on: November 20, 2019, 04:57:18 PM »
BTW: A TH350 will be square with a corner cut off at an angle, whereas a TH400 is (roughly) Texas-shaped.

Or shaped like a cake
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Online Shifty

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Re: Transmission and transfer case ???
« Reply #11 on: November 21, 2019, 08:32:30 AM »
BTW: A TH350 will be square with a corner cut off at an angle, whereas a TH400 is (roughly) Texas-shaped.

Or shaped like a cake
Yikes!
87 V20 Standard Cab Longbed (current)

87 R30 3+3 Longbed (days of yore)