Author Topic: K5 blazer transfer case  (Read 1002 times)

Offline BradRuiz 83

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K5 blazer transfer case
« on: January 10, 2020, 08:30:15 PM »
Does any one have a clue of what transfer case is in a 1979 Chevy K5 blazer... it has an automatic transmission in it. Some people say it might be a NP203 or an NP205

Offline Irish_Alley

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Re: K5 blazer transfer case
« Reply #1 on: January 10, 2020, 09:31:17 PM »
if it was stock it should be the 203 but since its 40 years old it could have even a 208 only way to tell is a visual check
If you canít 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 BradRuiz 83

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Re: K5 blazer transfer case
« Reply #2 on: January 10, 2020, 10:13:04 PM »
Ok thanks, will do...

Offline JohnnyPopper

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Re: K5 blazer transfer case
« Reply #3 on: January 11, 2020, 12:59:25 PM »
This link will show you a NP203 and how to make it better.

https://ck5.com/forums/resources/mile-marker-np203-part-time-kit.68/
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 75gmck25

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Re: K5 blazer transfer case
« Reply #4 on: February 06, 2020, 09:29:33 AM »
Whether you want to install a part-time kit will depend on how you want to use it.  The NP203 full-time has been very popular for plow trucks and maintenance trucks because they maneuver better in the snow in AWD, and can switch to 4WD whenever needed.  The differential in the transfer case allows it to drive all four wheels on a hard surface without binding.  Thats very useful when plowing a parking lot and driving on and off hard surfaces.

The NP203 is chain-driven, but a very strong chain-driven case.  However, trucks of this vintage had really bad gas mileage and the part-time conversion was very popular as an effort to get a little better mileage.   In general, the part-time kit makes the NP203 a little less reliable because it changes the way oil is circulated in the case when in 2WD mode.  You need to run it in 4WD periodically to keep it properly lubricated.

Bruce

Offline JohnnyPopper

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Re: K5 blazer transfer case
« Reply #5 on: February 06, 2020, 02:55:30 PM »
If you do that, try not to do what I do-Forget that your in 4WD without the hubs locked... :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