Let's see your FJ case swap

A DPDT switch to activate the ADD is easy enough to make once you wrap your brain around the instructions in this thread (at least it was for my small brain). I'll repost the schematics below:

 

For the 4wd and Low yes you would connect them to the 4wd and Low switches on the transfer case, you can use the existing wires.

For the rear diff lock you would either need to use a switch and relay to operate the locker like the Locker Anytime Mod or find a 4WD ECU from a 2wd TRD OR to use and keep the factory locker system.

 

You enabling, spoon feeding jerks...this might actually happen...

So now my issue would just be finding parts in a short timeframe. With a conventional 4WD case, miles wouldn't scare me much - but it struck me that full time with a viscous center diff, I may be well served to get something low mile/creampuff; am I off base here or are these going to be prone to wearing out?

Edit: I have read the center diff is viscous; now I also see people say it's torsen (so, all gear based/no fluid); does anyone know definitively?

 

@moon22 said he didn't need the lights.

Last page of the locker thread, I have a spare relay that id sell.

 

Well the 4wd ECU controls the lights so if your removing that then the lights won't work unless you tap into those circuits as well, he was talking about keeping all other functionality though.

 

There's definitely a Torsen center diff in the VF4B FJ Cruiser AWD case.

Toyota only uses viscous couplings in their recent North American unibody cars, SUV's and crossovers (Matrix, RAV4, Highlander, Venza, etc). Torsen center diffs are used in Land Cruiser, 4Runner and FJC ladderframe SUV's (and the cool JDM Celica-based AWD cars of the 1990's).

Furthermore, my understanding are the VF range of transfer cases are pretty bulletproof. Because of that, you'll find your old transfer case is pretty worthless on the open market. (They don't often break so nobody needs them). So I don't think you'd have issues with a well-taken-care-of higher mileage AWD case.

 

I have purchased two VF4B’s for my tacos and they have both been solid. One had 30k miles and the other around 120k. I don’t think you have anything to worry about, just change the oil in it and start enjoying it. They will cost a little more than the auto trans version. I think I paid $600 or so for each of mine.

I did wire up my sensors to the cluster so my lights work just like stock. I am running the FJ non-ADD tube up front also.

edit: most salvage yards offer a 30 or 90 day warranty with their parts. Get that thing installed as soon as you can after buying so you can put it through its paces and make sure all is well

 

[Bear with me - phone posting...]

I saw that at way too early this morning - that was for locker anytime? I may want to do that either way; PM me with the deets if you want!

I don't have an overwhelming desire to physically remove the computer, so if simply hooking up the sensors to the existing harness gets me functioning lights, why not..

This eases my mind. I did doomscroll through some FJ forums with a bunch of TC failures early this morning, seems like mostly issues with being stuck in low or neutral. Early model issues maybe?

Salvage yards are probably going to be my only route with this little time to prep/hunt. This scares me not a little so yeah getting it in and tested is going to be big.

Question on front driveshafts - anyone try just using the FJ's? I may get a decent package deal from someplace if I get the TC, shaft, selector lever, boots, etc..Rock Auto lists driveshaft lengths on their refurb units but it seems they have different specs for different brands so that's a hard one to go off of (I would rebuild an oem myself, assuming the U-joints and boot kit I already bought for mine will cross over).

 

There's more to it than that, your gona pretty much have to remove or at least unplug the 4wd ECU if your doing what I understand.
I was just saying the wiring is there under the truck for the 4wd and Low sense circuits. The 4wd circuit is Pin 3 (Light Green/Black) at the ADD Actuator and the Low circuit is the Yellow/Black wire at the L4 Detection Switch on the back of the Transfer Case Actuator.
If you wanted the lights to work you would just have to cut and tap the indicator circuits to the 4wd and L4 circuits at the 4wd ECU.

I've seen a few people have that issue but it's not very common, I've only seen one that was a confirmed failure of the low range hub.
https://www.tacomaworld.com/posts/28982639

Actuator issues are the most common but majority of the time it's due to the vent hose cracking/coming off or non-use.

 

Sorry, it's busy at work for me. But i just completed most of this. The relay allows you to operate the locker anytime. You would remove one harness from the 4wd computer.

when you swap a manual tcase you just wire into the plugs on the tcase for light functions. The actuator isnt functioning anymore. And you will lose front add unless you do the dpds switch or fj tube.

the thread is a mess, but info is there

 

I've got a yard quoting me $650 shipped for a case, selector & boots (if they still have them), and FJ front driveshaft from the same rig.

Currently seeing if they have a 750F driveshaft (if they do might just play it safe and get the 750F front too..or take a ~$50 hit for the team, get both, and find out if the FJ shaft works to make yard ordering easier...for the 7 people worldwide interested in the AWD swap, but, I digress).

Not excited about the 260k miles but if consensus is it's not a big deal, this whole pile will arrive at my door for about what the next cheapest case is that I can find before shipping. Then sock away money for a mintier one should the need ever arise I suppose..

 

No problem - locker mod is down on the priority list under "nice to have" so whenever you get the time to get back to me is great.

Yes - also illustrates the importance of direct attachments and pasting info instead of 3rd party links, but, we'll get through it!

Thanks again for everyone's input!

 

FJ driveshaft should work fine because RA60 RA62 should be the same length. The A750F part time or the 3rd gen RC62F part time should also work because both transmissions are an inch longer (the same amount of the full time transfer case), so they give you the added length you need.

And then for guys like me, if I went full time, I could use a driveshaft out of a full time 4Runner with the A750F, BUT I don’t have a rear driveshaft option. Have to hack up the front half to put the carrier bearing in the right spot. Annoying. That is the only reason I haven’t swapped to the VF4B.

Something to know about 4R and FJ shafts is they are a Japanese product. They do not use Spicer branded 1310 joints, they use some other weird joint that has inner clips instead of the outer style. Not a problem, but less options for them for replacement. You can get a spicer product though, but greasable only. Again, not a problem, just worth knowing the nuances. I would prefer the Tacoma version of the shaft myself. Ought to find plenty of them from 2nd gen autos or 3rd gen manuals.

 

Good points @BLtheP and I wouldn't have guessed that about the T4R/FCJ shafts. I was actually just wondering if there are any other differences due to them being full time and not part of an "operate under 65MPH" system?

Does this mean a 3G auto shaft for the rear will work as well if I am doing the math right..?

 

I wonder if you would have to swap input shafts like the 6mt guys have to for the FJ tcase swap?

@moon22

 

Technically it’s only below 62 mph that you can shift, but you can drive any speed in part time. So really there are no functional differences in the driveshafts. Don’t know why they use different different ones, probably just the way Japan prefers to do it vs North America. Not sure. Functionally either will work and bolt up fine if you get the right length.

as for the rear, the length would be correct, but the centering hub on the 3rd gen MT driveshaft will bottom out in the yoke hole before the yoke is seated. I learned this when I tried to swap an 8.4” TrueTrac diff into my 3rd gen in January. So I’d go for the 2nd gen auto 4x4 rear.

 

AFAIK the AWD tcases were only available in the manual trans FJs so that shouldn't be necessary

 

The VF4B should fit any 6 speed manuals fine to my knowledge.

 

I don't have my 4wd ecu plugged in, but my 4hi and lo lights work. I suppose i tapped into the rest of the harness for the functionality. I was just following the instructions, i don't know the reasoning behind it

 

Well well well...I stumbled in to this: The front/rear yokes LOOK different; but I threw calipers on and got the same 46mm register diameter on both, and my attempts to measure the bolt openings (to extremums) also showed about as identical as I could see through my shaking, shivering hands..my current front shaft is in no need of replacement so that would great to be able to use it.