4wd swap blues

Well, I just spent 4 hrs round trip driving to pick up what I thought would be a suitable donor truck to swap my 2002 Prerunner v6 auto w/ 4.10 E-lock rear end to 4wd. The 4runner donor in question proved to have a busted transmission and transfer case and the front diff had more oil on the outside of it than the inside. Left with only a set of wheels. Getting a whole donor vehicle with the exact right pieces is getting harder.

Now for my question…Can one of you old timers point me to the definitive thread(s) for walking through the particulars, especially parts, for a swap? I want to stay with auto tranny and prefer J shift transfer case with ADD front diff. Looks like I may have to hunt down parts individually, which means I need a really thorough shopping list.

Other useful info for those kind enough to respond:
-I am in middle TN, not as lucky with used OEM parts sources as it appears the west coast is
-truck has 150k miles
-stock suspension and no plans to lift, if I ever do would be no more than 2”

Lastly, I have used the search function, but was a little overwhelmed with the results. Figured some kind soul my have the perfect thread(s) book marked. Thanks for your help and I welcome all advice…except sell and buy 4wd. The truck is sentimental and today’s prices seem like a pro for 4wd swap, not a con.

 

Diffs are a dime a dozen; you can find them as cheap as $50 bucks.

Someone has dibs on mine; letting him have it for free.

If you can down your own vehicle, just replace the output shaft on your own transmission.

The 4Runner you would've pulled parts from would have a different stall speed torque converter too.

And depending on the year of the 4Runner, could've been drive by wire (01-02).

You're not looking for anything difficult/hard to find aside from possibly the j shift transfer case.

 

Thought about doing a 2wd to 4wd in the past... then I sold the 2wd truck and got my 4wd. But in this economy tough right now...

 

Thanks Kwik. 4runner was a 1999. Will a A340E torque converter not work with A340F? I have considered the tailshaft swap as last result. Want to minimize the amount of time the truck was down as this one is often my DD.

Not terribly concerned about being able to find the parts, just having a comprehensive list of what I need if I buy piece by piece, instead of donor vehicle route. I am 80-90% clear on the specifics, but looking for the perfect write up to follow as a guide and give me piece of mind.

 

There's no perfect write up maybe for a few reasons -

Many parts interchange easily, so it's really easy to figure out what you can keep, replace, etc.

There are varying swaps such as push button or J shift, and manual hub or ADD.

The easiest is J shift and manual hub on any 1995.5 - 2002 as everything is mechanical, and only 03-04 have drive by wire.

 

Spindles -

All 4Runner and 6 lug Tacoma spindles are the same. Tacoma's were available with and without ABS, so that tab will be missing on some spindles. 3G4R's came with ABS, so you'll find the tab on all of them. Knowing this, you can keep your current spindles (or buy from any one of the above mentioned), and press in new axle hubs and bearings. The axle hubs are different for manual hub cv axles than they are for ADD cv axles; Prerunners are different as well in that they can't accept any cv axle.

Front diff -

All 4Runner and 6 lug Tacoma differential's are the same. Gearing is where they vary.

Front diff tube -

There are only two variants, one from a manual hub setup and one for an ADD setup. All 3G4R's have ADD diff tubes, whereas Tacoma's had either ADD diff tubes, or manual hub axle diff tubes.

If for some reason you used manual hubs, you can use a metal clamp to keep your ADD diff tube "engaged' to work as a solid setup like the manual diff tube does.

Transfer case -

I'm unfamiliar with the changes between auto and manual, but can tell you that the input gears on a 4 cylinder are 26, and 6 cylinder are 23. You'll want to make the engine on your truck to the engine on the donor truck when choosing a transfer case.

As far as cases, push button and J shift were both available in both 3G4R's and Tacoma's.

Careful not to accidently pull a Multimode transfer case (only on 99-00 3G4R Limited as an option). This has a push button setup as well as a J shift pattern due to the setup running as AWD, then 4H, then 4L.

Aside from that, not sure what else to add (no pun intended).

 

I know @BartMaster1234 will be creating the perfect write up for a 4x4 swap, but it'll take time as he's extremely busy, plus it'll take some time to detail separate instructions depending on the type of 4x4 one will convert to -

Auto to Manual transmission with 4x4 conversion

ADD cv's, ADD diff tube, with J shift

ADD cv's, ADD diff tube, with push button

Manual hub cv's, with ADD diff tube, with J shift

Manual hub cv's, with manual diff tube, with J shift

Output shaft swap when needed

Transmission valve body swap, where applicable

Spindle parts, whether using current (Prerunner) spindles and swaping axle hubs, or using a spindle set up for a different style cv axle

Drive shaft lengths

Torque converter speeds, as they vary from a Tacoma to a 4Runner

What year vehicle's to source parts from

and many more details I'm sure I'm forgetting...

 

Curious. Why wouldn’t the multimode transfer work?

 

Didn't say it wouldn't, they're just harder to find and could pose a different animal altogether with the ECU difference.

Pushing the 4WD button puts the vehicle in "AWD", keeping the center open, allowing the front and rear driveshafts to spin at different speeds.

Moving the lever down, locks the center, and puts the vehicle in 4x4 High.

Putting the vehicle in Neutral, and moving the lever to the right and up (like a J shift), then back to Drive, puts the vehicle in 4x4 Low.

The transfer case does operate in a mechanical fashion as far as going from 4H to 4L and back, so you can use it for that, but the "AWD" part is electronic.

 

It's pretty fair to say that you've got more information in the few posts than you needed

Just make sure you buy new drain and fill plugs, crush washers, cv axle seals, and fluids as needed for all your swap parts.

One popular (and convenient) mod is getting rid of the hex type plug and going with one that uses a metric head on your front diff. Part numbers shown below -

Front diff fill 90341-18060
Front diff drain 90341-24016

 

The 4runner I looked at today was a Limited with push button on the 4x selector. But busted case due to collision.

For ADD, are the particulars for that I need to be mindful of? Is there a vacuum vs electric option? Is there a particular transfer case option that needs to be present for ADD?

 

Yes, see I was listing so much stuff I forgot about that.

On Tacoma's, 2000 and below are vacuum, 2001 and up are electric.

Unsure what the year range is for a 3G4R.

ADD was available on either push button or J shift transfer case regardless if it's a Tacoma or 4Runner; 4Runner's only came with ADD as I mentioned above.

 

Kwik you have been awesome!! Thanks and the only info that is too much is that not used and I certainly intend to use it.

for electric ADD, what is the electric signal actuated by? I had assumed the button on the Jshift, but it seems that was incorrect and that was multimode?

 

J shift does not have a button at all.

When you move your J shift to 4H, a signal goes out from the transfer case and to the ADD actuator on the diff tube.

Multimode works in the same way as Push button in that, pressing the button, sends that signal to the ADD actuator.

 

Just how far would you travel to get a Donor vehicle ?

Keep checking the Toyota Forums one will appear sooner or later.

I don`t know if you checked Carpart.com yet??

Myself the whole vehicle is much easier then one piece at a time.

Good Luck

 

No further than I can drive to and back in a day. Got a couple guys who buy and part out vehicles that would be willing to pull the parts for me to pick up but every yruck ends up being a Prerunner, 4cyl or busted from a crash.

The BST stuff to this point as all been too far to drive.

Donor is definitely the easier option. Give me a truck with same engine and tranny and pretty assured the swap is easy peasy. Take a shopping list and there are a few options that are easy to screw up and all parts either not work together or not work with my truck.

 

What you're asking for isn't difficult, and found in many varying vehicles.

 

Not trying to be argumentative, but not my experience this far. See beginning of post 16, not to mention post 1. I know I can find the parts and intend to broaden my search from one donor vehicle for all parts to picking and pulling from multiple trucks. The info you have provided will be super helpful there. My ignorance will be the problem.

 

I’ve been writing a comprehensive guide to do a 4WD swap for the better part of four years, I just never finished it haha