Question about the transfer case on a 2000 S10 Blazer with the 4 button switch. I'm not sure which t case this is, but is there actually a difference in 2 wheel drive a 4 wheel drive High? The reason I'm asking is, I have the t case on the bench and I removed the control motor and I was shifting the position with a wrench. It seemed to only have 3 position.
1 position the input and both outputs turned together. seemed to be high.
the next positon, both output shafts moved but the input shaft did not trun. Appear to be a neutral position like you would have on a manually shifted t-case. The last position the input shaft and both outputs turned together, and buy the difference in revolutions beteween the input and output it was 4 low. If this is true, the only real control over the 4 wheel high and 2 wheel drive is the vacume actuator on the front diff.

 

that is wat really puts the truck in the 4wd i am not to sure about that t case in the chevys i know more anout ford i just bought an 88 blazer i am sorry

 

You have the NV236 transfer case. There are really only three detents that you can feel. The clutch in the transfer case is preloaded so there is always some kind of connection between the front and rear output shafts. When in 2HI, the front driveshaft will still turn, but really is only turning due to the preload on the clutch in the TC. When you put it into 4HI, the clutch locks up fully. When in Auto4wd, the front axle will be engaged by the vacuum solenoid mounted on the firewall, but the transfer case may only be driving the rear axle until which time as it may partially or fully power the front axle by applying the clutch. Due to the variable lockup used in this transfer case, you will not find a detent for 4HI.

 

So, if I understand correctly, by manually engaging the front axleusing a after market posi lock set up I will have 4 wheel drive high and even 4 wheel drive low if a rig up some kind of manul linkage. The reason I asking is my blazer is not shifting into any of the 4 wheel drive settings, in fact the 4 wheel drive selectorbuttons on the dashare dead. It was diagnosed as thecomputer located in side kick panel in the cab bad. At a cost of $700.00I do not feel the truck is worth it. I'm already having trany problems which I in the process of switching out with a used one.

 

If the switch is "dead", then putting in a posi-lock setup will not cure your problem. It will only engage the front axle when you pull on the cable, not shift the transfer case.

How did you diagnose the problem to the TCCM? What testing was done? If codes were read, what codes were present (Cxxxx)?

You can test the switch relatively easily. You can also check and clean the connection at the TCCM and encoder motor which may cure your problem.

The TCCM is hardly $700.

 

got my TCCM replaced for around $400 including labor