manula lock front dif???

my 1993 siverado front dif wont engage. found out it is the vacume actuator. it is going to cost me 160$ plus to fix it but i dont have that money. is it possible to manualy lock the front dif.?

anyone have any ideas?

If the thermal linear actuator is bad, you can replace it with a cable set up to manually lock it, but its gonna cost about the same (desert rat sells for $179 I think). I'd just save up and buy the thermal one or maybe go to a salvage yard and get a used one.