QT engagement problems

[quikclimber]

I have the true borg warner QT transfer case, with the glovebox mounted vacuum swithch. sometimes if the tires are spinning ill flip the switch, and the light comes on, and the front and rear feel locked togeather...traction is good. other times i flip the switch, (i can hear the vacuum hiss) but the light doesnt come on the TC doesnt engage. should i check the vacume lines, the controll plunger thing that is attached to the TC, any advice would be great. thanks a ton

[joe]

The lines would be the first thing to check. Look for any cracks at the vac reservoir also to make sure it's not leaking. Since it is engaging occasionally the vac motor is prolly ok. The switch can go bad too. Check the the operation of both(after you know the lines are good) with a hand held vac pump.

[Aaron]

My switch failed in my old 79 and caused the problem you are having. You could hear the vacuum if you had the switch out and listened closely to it. I seem to remember doing something to it that fixed it. Maybe I replaced it, it was a while back.