i currently have a 05 4runner SE. Its a v6 and a 2wd

during the recent snowstorm in georgia, i got stuck in a hill and couldnt make it up due to loss of traction and such and now im considering changing to 4x4. I know alot of you will suggest buying a car with 4x4 but i love my current runner and wouldnt be able to afford another one anyway. Does anyone know the process of doing it, the steps or anyone who have done this? And a estiamtion of how much this would cost?
It is not terribly expensive to do the conversion, likely even cheaper than when I did mine, since there are probably more donor vehicles avail.
If you plan it right and get all the parts ahead of time it takes the better part of a day, in short it is the equivelant of tranny swap and hub replacement. I broke it down on the 120 forums.
Things to consider before a 4x4 conversion.
Do you want full time 4x4 or part time?
New parts or used?
What parts are interchangeable?
What is your budget?
Who is doing the Swap?
The reason you have to have a clear idea of all these questions is because a 4x4 conversion can become a handful, trust me I know.
First here is what you need.
-4x4 Transmission with Transfer Case (V8 is WD and V6 is 4x4)
-NOTE: it is cheaper to buy the entire package at a salvage yard, reason being, the transfer case does not come with the adapter from the tranny to the T-Case and that part alone at Toyota is over 300 dollars. Best to just pull the entire set
-Front Diff (with matching rear gears if you can pull that off.)
-Both CVs (Right & Left )
-Both Drive Shafts (Front & Rear)
-Front Diff Mounting Bracket (Y Shaped Bracket that holds up the Tail)
-Front Diff Mounting Arms w/bushings (you will also need the long bolts, I recommend also using a diff drop kit also)
-Front Hub and Bearing Assembly (the old one gets destroyed when removed to install Drive Flange)
-Front 4x4 drive flange
-Front Wheel Bearing Seal Kit
-4x4 skid plate
-4WD Shift Selector (2wd T4R are prewired for the switch)
-4x4 controller ECM (89530-35310)
-Toyota pin convectors for ECM
-ECM Plugs (90980-12149 & 90980-12150) Note: one plug is prewired, the second plug (from the ECM to the t-case you will have to make your own harness or cut one out of a donor, the parts are not avail via Toyota
-4wd dash light (if you want your truck to tell you when it in 4x4 you need the gauge cluster from a 4x4)
-Transfer Case Cross Member
Transfer Case Mount
If you can find a wrecked vehicle in the junk yard, you should be able to pull everything off of one vehicle for the swap, it will save a lot if time if you can pull the entire front spindles from a donor that already has the 4x4 drive flanges. Another benefit to getting everything from one source, is you can probably get a pretty good deal. Just over a year ago we were going to do this conversion on a friends 2wd FJ. We found a V6 4runner at a local junk yard, brought the list of parts in and initially the guy wanted $2100 for everything, but after talking to him about what we were doing, he said he could do $1800. If you decide to do this, I hope you have similar luck.
That is the entire list, I am pretty sure. There are things like fluids, and solder, and elec tape, and so on.
Okay here is the deal, you can do this swap with these parts in about a day (depending on the speed of your tranny install. All the parts are bolt in except the Wiring harness. It cost about 2700 in parts if you use new stuff on all but the tranny, t-case, and diff. The 2700 I spent included lift springs, TRD Tacoma struts and shocks, and oil cooler. I also did a diff drop on the diff, and did a top out spacer lift on front and rear. With tires ( I still have not put the new tires on because they did not fit the stock wheels) bumpers, sliders, paint work, HID Lights, and all the crap I added for Summit 2010, I spent about $7500. My point is the 4x4 conversion was cheaper than my other mods, and once I got the parts sorted out it was pretty easy.
Sources for parts
Local junk yard for all hard parts, tranny, t-case, ECM, CVs, everything if you are lucky
All Pro for diff mounting brackets if you diff does not come with them
Tacoma selector switch will work if you can find one in the junk yard, even if you use a 4x4 switch in an AWD conversion it will still work, you will just have 2 positions that give you 4low.
Tacoma(05+) and FJ drive flange, CVs, Diff, and diff brackets will fit the T4R
The cross member can be modified to work but it is not easy and you have to be able to weld
There is a way to do this with a Jeep NP231 Transfer case and some custom drive shafts, I also did this swap into another one of my trucks, the cost is far less but the labor and fab time is much higher. And it requires you to cut the last 3 inches of you 2wd transmission tail shaft off, and you have to buy a short shaft or slip yolk eliminator jeep kit. If that sounds like Greek to you, that is not the way you should go.
Hope this helps.