front driveshaft not engaging

[slvt4r]

I recently had the AT on my 94 T4R V-6 rebuilt. Everything works good except the front driveshaft does not engage when the shifter is in 4H or 4L. I realized this after I took it our of the shop. When I called back they said yes they knew that and the transmission side checked out but their was something wrong in the vaccum system. The transfer case does shift down in 4L. The transmission is electronically controlled. The vaccum system has vaccum in several places. Any ideas on were I might start the trouble shooting. I'd like to do it myself as I already gave the shop my kids college tuition for the AT rebuild.

 

[toyoboy]

you say the shaft coming from the transfer case is not turning? or the front axle?

 

[slvt4r]

I was thinking the driveshaft, but then someone said maybe the axle is locking. So I am going to pull the driveshaft off sometime this week to make sure which end is not turning.
Thanks for your interest.

 

[jhinderliter]

most likely they unplugged the front dif while removing the engine..have a look at your diff and look for a cannon plug that dosnt have a home
peace

 

[slvt4r]

Thanks for your advice. I wished it was as easy as an unplugged electrical, but everything seems connected. It is the front axle which is not locking. I checked all the connctions to the differential and everything had a mate. I made another interesting discovering whilw playing around. Their are 2 vaccum hoses leading to the differential. One had vaccum and one didn't. I switched the tubes and heard a rapid clicking sound. Investigation showed that the clicking was comming from a small canister, a little bigger than a cigarette lighter conected to the vaccum hose. Also, the 4WD light on the dash was flashing. So I tried things out and the 4WD worked. However, that clicking continues so I am going to trouble shoot electrical current through that vacuum circuit?