4x4 doesnt work after changing cv joints

'90 gmc s-15 pickup.

its not like i use the 4x4 every day, but i thought it was working ok. inspection sticker time i had to do some service. changed both sides cv shafts, idler arm, and both sides upper a-arms. now the 4x4 doesnt seem to kick in. i checked the vacum diaphram thats supposed to pull it into gear (under the battery) and it seems to be sucking in just fine, and pulling the cable like its supposed to, but the front axles just wont lock in. the light doesnt go on either. perhaps i did something wrong when re-installing cv axles? if anyone can give some advice i sure would appreciate it.

Dave.

check diff end of cable. maybe only the cable is being pulled if it is broken or not attached to pin exiting diff. using chilton book i disconnected diafram end of cable, 3 bolts at diff end, and pulled back cable cover and attachment plate from diff so i could see cable linked to pin and lubricate pin and pin seal with a lubricating rubber seal rejuvinating fluid. reapply gasket sealant all around before reattaching cable cover end plate. i had leak there. this stopped it.

thanks. i never thought of that, but it makes sense. i will get to it within a week or two and post back to let you know how i made out.