[Jonx4x4]

My friend just purchased a 77 K5 Blazer with the Cheyenne package. It is a pretty nice truck for as old as it is. Anyways, before we can take it out to go test it out, I need to know what kind of 4-Wheel Drive system it has.

What T-Case does it have?
Part time or full time?
Where is 4HI, 4LO, and 2HI(if any)?
Is the front axle constantly engaged, or does it have auto locking hubs?

Thanks guys! 8)

 

[Jonx4x4]

Oh yeah, and what gears would be in the axles?

 

[Sandman]

Lots of info HERE.

I think you will have 3.73 gears. If there are no hubs, then it is a full time (203).

Let us know how it goes!

 

[4x4Freak]

If it has an auto tranny it will most likely have the 203 (full time, fr to rr: 4 LO LOCK, 4 LO, N, 4 HI, 4 HI LOCK). If it has a man. tranny it will have the 205 (part time, fr to rr: 4 Low, N, 2 High, 4 High). I would think it would be more likely to have 3.07s than 3.73s, but it could have anything from 2.76-4.10.

 

[Jonx4x4]

It feels like it only has 3 selections on the t-case shifter. It has an automatic. There are no manual locking hubs on it, so Im kind of confused...

 

[4x4Freak]

It should have atleast 4 shifter positions no matter the t-case. It is possible that it's been swapped out. Look at the t-case, the 205 will have a small cover in the center with 3 bolts holding it on the back of the case. The 203 has two pieces, the case with the chain and outputs on it and the range box that bolts directly to the transmission. The shifter also has two rods instead of one; one of them goes to the back half and controls the 4wd and the other goes to the side of the range box and controls high, low and neutral. It's not uncommon for the shifter on a 203 to get dirty and hang up, usually a little oil or wd40 will loosen it up.

 

[Jonx4x4]

Well, if all goes according to plan, Im going to crawl under it, and see what kind of T-Case it has. Ill let you know.

 

[jrz_dad]

Jon - if you need any help let me know - I recently bought a 77 GMC Jimmy Full Size and had to repair the Tcase on mine - so I know first hand what the 203 looks like!!... :thumb:

 

[Jonx4x4]

Yep. Its an NP203. Can we run manual locking hubs or would that be bad?

 

[Anonymous]

I think you mean "it's" or "it is" not "its". Are there any other NP203? Do you mean you and me? I work on all kinds of computers, Mac, IBM or Unix. It doesn't matter to me.

 

[Jonx4x4]

damned bots! :roll: :finger: :finger: :finger: :roll:

 

[AJ]

yeah, you can run manual locking hubs, and you would be OK... Milemarker also sells a part time kit for the T-case that works pretty good as long as you remember to shift it into 4X4 every so often to splash oil up in the rangebox gears.....

 

[Sandman]

You need to get the part time kit if you are putting hubs into the front. I recommend doing it. Save some wear and tear.

 

[4x4Freak]

You wont go anywhere with the hubs unlocked unless you lock the t-case into 4wd, which defeats the whole purpose anyway.