4x4 is not engaging front wheels

i dont know whats wrong with my 2001 tacoma 4x4. When i shift into 4x4 my transmission shifts into gear but front diff isn't engaging what;s wrong please help

 

What transmission do you have?

Auto or manual?

Do you have a gear shift 4WD or a switch?

Are you seeing the 4X4 light on the dash at all?

Where are you trying to engage? Are you driving? Are you not moving? Are you on a hill? Are your wheels straight?

 

auto tran no light on dash and front axle is turning

 

ADD issue?

The ADD (Automatic Disconnecting Differential) is how our Tacomas can have 'shift on the fly' 4WD hi-range and 'free wheeling hubs' (auto locking hubs)... but instead of auto locking right at each hub, which requires driving backwards to unlock... Toyota has a device on one of the axles next to the front differential that connects and disconnects with an electric motor when you go into or out of H4. Only the two front axles turn (with the tires) but not the differential gears or front drive shaft... saving wear and improving mileage.

There have been some problems with the ADD that require fixing or learning how to engage it manually, so you can 4 wheel. Search ADD fixes here.

 

Is the front axle DRIVING or just turning?

Do you have a Shift lever or a push button?

 

yes the front axle is spinning and i have a shift lever

and i'm not completly sure yet but my add may have been bypassed i was following the vac hoses and they ran up near the battery and were capped off

so what do i do now did someone not get it engaged or how do i manually engauge

 

that may be the breather

 

Yup,
The two rubber tubes that are attched near the battery with silver caps on top are the breathers for the front differential and the ADD. This is something many of us have down on the rear differential so it doesn't get contaminated... see link in my sig. below!

 

ok yeah thx i did check out your links

so does this mean its been discoonected but not engauged?

 

Front differential and ADD breathers: