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73-87 Chevy _ GMC Trucks => Blazers/Jimmys => Topic started by: BradRuiz 83 on January 10, 2020, 08:30:15 PM

Title: K5 blazer transfer case
Post by: BradRuiz 83 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
Title: Re: K5 blazer transfer case
Post by: Irish_Alley 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
Title: Re: K5 blazer transfer case
Post by: BradRuiz 83 on January 10, 2020, 10:13:04 PM
Ok thanks, will do...
Title: Re: K5 blazer transfer case
Post by: JohnnyPopper 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/
Title: Re: K5 blazer transfer case
Post by: 75gmck25 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
Title: Re: K5 blazer transfer case
Post by: JohnnyPopper 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