2WD to 4WD Conversion, Part 1

2WD to 4WD Conversion, Part 1

2WD to 4WD Tacoma Conversion

Toyota has made a number of variations of the Tacoma, from the venerable 5 lug standard cab to the unmistakable Double Cab Long Bed 4WD and everything in between. Some have purchased the awesome Prerunner version of the Tacoma, have built it to the exact specifications wanted, then taken it out on the trails and have loved it.  But, some have been left wanting more when the trail got tough; you got left behind, even with the addition of the factory rear locker. You just didn’t have the extra benefit of power going to those front wheels.


So what do you do when you want a 4wd version of your truck?  First, you can sell it and then go purchase the 4wd version of your truck.  Only problem, you’ve already spent a fortune on all the upgrades you wanted and your not going to get that money back.  Not to mention the 4wd version is quite a bit more than your Prerunner.

So what do you do?  Convert yours to 4wd!  Yes that’s right.  Use all Toyota factory parts and convert your Prerunner to a 4wd variant of the Prerunner.
Is it easy?  No!  Is it worth it?  For some, yes.

So lets get started.

This truck was a 2wd extra cab Prerunner with the 4.0 motor and the automatic transmission.
First we need to get the list of parts.  The Prerunner and the 4wd trucks are not the same truck.  The frames are just a small bit different, they have transmissions that are not the same at rear, the transmission mounts, and the drive shafts are also different. Not to mention the front drive system that is in the 4wd version is not currently present.

You will either need to find a donor truck to get all the parts needed, or go to Toyota and buy all the parts, but that gets very expensive.  In the past we have just found wrecked 4wd trucks and gotten the parts we needed from them and then purchased the rest of the parts we needed from Toyota. This way is more cost effective.

You’re going to need all the front drive components such as the front differential and ADD stuff, the front drive hubs, front drive shaft, CV axles and the breather tube for the front diff.  You’ll also need to figure out the wiring if you don’t use the Kit that RockSolidToys.com has for the electronics within the conversion.  You will need the A750F version of the automatic transmission if you have the automatic.  We haven’t done a conversion on a manual transmission truck yet, so, I don’t have the info on its transmission but it will have a different rear end like the A750F auto has.  You will need a Transfer case. Since this is a swap, why not use the best t-case that Toyota has ever built? Use the t-case from the FJ Cruiser.  It is fully manual and bolts right up.  This transfer case has been in service long before the FJ Cruiser came along.  It has been used in a number of trucks around the world from the Hilux and Prado’s, to some of the FJ series trucks that we don’t get here.  They have even been used in non-Toyota vehicles as well.  Finally, you’re going to need the cross member from the 4wd Tacoma as well as the front drive shaft and rear drive shaft.

So lets stop wasting time and get into this swap.
First, as many of you know, the Prerunner and the 4wd version of the 2nd generation Tacoma uses the automatic A750F or A750E transmission behind the 4.0 motor. The difference between the two is the rear extension housings. This one is for the 2wd version and has no way to accommodate a transfer case.

Notice that the end of the transfer case comes to a cone shape in the rear where the drive shaft connects.  This is far different than the rear of the 4wd version of the same transmission.  Below is the 4wd drive transmission.  Here you can see that it has a rear adapter that can accept the transfer case instead of the driveshaft.

Internally these two transmissions are identical.  It’s just the rear portions of each transmission that is different.
Now that we have all the parts, it’s time to start tearing down the truck to start the transformation.  With this truck the owner added a Marlin Crawler “Taco Box” for the ultimate in 4wd fun.  Everything else is the same if you don’t use the crawler so we’ll share that info with you as well.
First we had to take off all the skid plates.  Jack up the truck and use jack stands for safety.  I can’t tell how many times I hear of someone using cinder blocks to hold up a 5,000 + lb truck.  Nuts!  Anyway, once you have the skid plates off its time to move to the transmission.  
Before we install any transmission we always flush them out.  While the transmission was getting flushed we turned our attention to removing all the 2wd hub stuff.  First we removed the wheels to get to the hubs. On the 2wd version there is a just a dust shield that needs to be removed on the spindle.  

Once the 2wd hub is removed from the spindle you can now remove the rear dust shield as well.

Now that the dust shield is gone we can start to install the front drive system.  The neat thing about this is Toyota has all the bolt holes and cradle stuff already set in the frame so that all we had to do is lift it all up and bolt it in.
Here is the front drive assembly with the ADD actuator.  You can get this from any of the 4wd 2nd generation Taco’s, the V6 4th Gen 4Runner, or the automatic FJ Cruiser.  If you use the one from the V8 4Runner or the Six Speed FJ Cruiser they don’t have the ADD diff and your Tacoma will be a faux full time four-wheel drive truck.  In other words, the front diff and all its components will spin as you drive, cutting down your gas mileage and adding wear and tear. Make sure the front diff you get is the ADD version.
Make sure you get all the bolts and washers if your getting this from a donor truck or you’ll be at Toyota getting parts.  It’s best to get the parts manual from Toyota to make sure you have everything because there are some special bolts and stuff that you will need.
Here you can see that the front diff is all tucked up in it’s new home.  Nice!!!

With the front diff installed it is now time to install the front CV axles and front drive hubs.  If you have parts from the donor truck it’s just a matter of bolting in the front hubs and away you go.  Make sure you use new seals, front and back when you install these.
The front 4wd hub is installed now.  Notice the splines where the CV axle will end up in.

Front CV axle’s installed.  Always use new cotter pins and castle nuts when installing CV axle’s.

Don’t forget the cap for the front hub.  Just makes for a really clean install.

So now that you have the front drive system installed, you have to get the ADD to work with your transmission and transfer case without a 4wd computer and we’re going to do it with a kit that ATO and RockSolidToys.com created. It is nearly plug and play!
This kit comes complete with everything you need to plug directly into your ADD actuator, a switch to control it, and instructions to install everything.

Once the kit is installed you can install the switch that activates the ADD. We decided to put it in one of the blanks on the left of the steering wheel.

When you turn the switch on and the ADD engages, the light will come on to let you know it's engaged and then you hit the switch again to turn it off and the lights goes out to let you know it's now disengaged.  With the front done it was time to do the transmission, crawler, and t case.

We’ll wrap up this install in Part 2 in the Next Issue.


[flickr set=72157632464196174]

download now
printed copyw

read online


Remember, tell your friends! They can subscribe for FREE using this link!

Find Us On: facebookbutton twitterbutton