my 1996 with a 233 np tcase is giving power to the front drive shaft when the dash switch says its in 2 high.I determined this by jacking all 4 tires off the ground and shifting into drive.when ido that,the front drive shaft turns and when I try 4 hi it only clicks but no front end engagement.I have put in a new dash swith and 3 used(junkyard)parts-tccm,encoder motor,switch on front diff in the cable housing.I have observed the vacume actuator under the battery.it is getting vacume and pullin the cable.I took out 3 bolts on the other end of the cable to make sure the cable was attached at that end too.it was.
so my problem is when shifting from 2hi to 4 hi or lo,the dash light flashes and the encoder motor clicks 3 times then nohting. so my tcase seems to be locked into 4 wheel mode but my front diff is not engaging.

 

Check your vacuum switch on the transfer case to make sure it's not stuck. I had the similar case and it turned out to be a bad vacuum switch. Oh one way to know if the vacuum switch is bad, remove your battery tray and check the actuator and see if its still under vacuum while in 2wd. If it is, then your vacuum switch is stuck and needs to be replaced.

 

thankyou for response,I was going to change it just to try,but my vacume actuator under the bat only pulls when it is clicking and flashing then it releases.do you think it could be responsible for my tcase being engaged all the time?is my tcase ever suppose to be in neutral?

 

your tcase shouldn't be engaged when you are in 2wd. Take the switch out and see if the ball bearing moves freely. If not, then theres your problem.

 

thanx nj4x4blaze, i will try that first thing tommorrow

 

put in new vacume switch,tcase still engaged,still clicking and flashing,but there was some fluid in the vacume hose so im glad i changed it

 

If the t-case never leaves 4wd, then the vacuum switch will always be activated, sending vacuum to the front axle actuator, engaging the front diff (provided everything up there is working properly).

So lets get back to the symptoms here. From the sounds of it, you think the transfer case is stuck in 4wd, but yet you state that it will not shift from 2HI to 4HI or 4LO...

Are you sure that it is the transfer case that is stuck and not a problem with the front axle engagement mechanism inside the front diff?

While you had the cable mount off of the front diff, did you pull/push on the end of the shift fork (what the cable attaches to) to see if it disengaged/engaged the front axle?

 

thanx for the responce.no i did not remove the cable housing completely,i tok out the 3 bolts,slid it back 3/4 inch but did not romove the clip.whith the motor running i had some one push the 4 hi and it would suck the housing as i was holding onto it back tight to the front diff.I was originally thinking my front diff was the problem when i noticed that my font drive shaft was turning when I thought i was in 2 hi.the dash light says im in 2 hi.thats why I asked in one of my earlier posts if a 233 has a neutral position.when i changed my encoder motor i put a pry bar in the slot of the tcase and crefully shifted the tcase manually but only got two positions out of it and neither one allowed me to turn the front spline that turns the front drive shaft.I put the used tcase motor on anyway but it acted the same.I am prepared to check the fork in the frront diff and replace the entire fdiff if i have to,but am want to understand why my tcase does what it does.both the encoder motor and tccm were used,thats why im still wondering about the not shifting part.

 

does anybody have any info on how a 233 tcase shifts into neural or where i can read up.after looking through a cheap manual and reading many posts,the exact series of events that take place when you push the dash button is still not clear.I know a lot more now after a month of switching parts and reading but now Im kinda stuck as to what to do next.if i can convince myself the transfer case motor and tccm and trnsfercase are all communicating,i can completely focus on frt diff.thanx for help.1996 blazer.

 

You might have to remove the driveshaft from the front diff yoke. Once you do this, with the tires jacked up off the ground, you can turn the tires to see if the yoke spins on the front diff or see if the driveshaft will free spin. This will pinpoint which one is staying locked. Then you can focus all your work on that part.