transfer case

[blackwidowk5]

I have a 79 K5, i just had the transmission rebuilt. They guy that did it looked at my transfer case as well. Said it looked like it had been modified. He thought it had been converted from all-time four wheel. I was wondering if anybody knows if my blazer was originally equiped with all time 4x4 or not, and if so does will the conversion kit cause any problems?

 

[Blazer79]

79 Blazers came with the NP203 transfer case. This is a full-time transfer case. This means there's a differential inside to compensate for turns. When you engage one of the LOC positions, you lock front and rear driveshafts, obtaining "real" 4wd. The markings on the shifter are LO LOC-LO-N-HI-HI LOC.

Some people install a part-time-kit which removes the full-time 4wd function and gives you 2wd instead. When you engage any of the LOC positions, you obtain real 4wd again. They do this with the idea of improving mileage.

Now that you have the part time kit, just engage any of the LOC positions once in a while to lubricate the front output of the transfer case. This is because it was designed to lubricate while turning, and since there is no more turning in 2wd, you need to engage 4wd to do it. Also, change the oil once in a while too, and use ONLY 30 grade ENGINE OIL, not anything else. That'll keep you from trouble.

I hope this clears everything up.



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[TheEmissary]

Re: NP203

If your K-series 4 x 4 had a THM350 or 400, there is a possibility that an NP203 transfer case is in your rig. These are common with full-time 4-wheel drive, and a lot of them have been converted to part-time 4 x 4.

The Emissary
1981 K5 Blazer 4 x 4
305 (LE9)/THM350C/NP208

Other vehicles:
1975 Nova

 

[ken]

Re: NP203

To put it plainly, 1979 GM trucks with 4 speed manual trannys had 205 transfer cases. With TH350 or TH400 autos, they had 203 full time 4x4 transfer cases.

ken

 

[blackwidowk5]

thanks for the info. It all makes sense now