2003 4Runner Limited 4wd V8 FJ tcased overlanding rockcrawling do-it-all build

Found it! https://adventuretaco.com/a-front-diff-drain-plug-that-doesnt-suck/

More info: Lexus part # 5443425-706 from is350 awd front diffs

Different part #, from the blog post above: the Lexus OEM version (90341-24016)

 

Took the 4runner out for an overnight camping trip to Mt Graham, here in AZ. This morning, the 4Lo light started blinking at me and continues to do so now, so it looks like the servos are fubar or need help. They work working fine yesterday, both 4Lo and the center diff lock. Now nothing, just blinky light. So, I'm leaning heavily towards selling it now as I don't want to mess with the crappy tcase or just replace it with an FJ case and Taco front diff. Parts alone for that swap are $2500.

Pulled the cover off the shift housing on the t-case and had about half a quart of gear oil dump out on me and the floor. So that means the shaft seal is leaking and the o-ring is also probably bad. Replacements on order. For now, the 4runner sits. Hopefully I can replace the seals and o-ring and get things working again.







First spot I stopped at to eat dinner. Decided not to stay the night here, too many people around.







Spot I found a little later. No people around at all, nice and quiet.





Not the most comfortable night. I'm 5'9" and had to sleep diagonally in the back. My pup was certainly happy tho. Dropped down to 52 degrees over night, so nice to get out of the normal AZ heat. I was at about 9000' here I think. No camp fires aloud tho, everything is just too dry right now so the fire danger is very high.



Lastly, a pic of the internals of the shifter housing bolted to the back of the t-case. You can see the gear oil still dripping. It should be dry in there since there's and electric motor to shift the center diff lock and 4lo in and out. Stupid design.

 

New seals for the shifter housing showed up today. I'll start gutting the t-case shifter tomorrow morning. Hopefully i can fix this without too much issue.



Oring is the external seal for the housing. The 2 small seals are the shaft seals for the shifters that run into the t-case. Got them here -https://www.avxseals.com/ProductDetails.asp?ProductCode=TC15x23x7

 

Here's my story with the actuator issues thus far.

4th of July weekend, I did an overnight camping trip up to the mountains in the 4Runner. Mine is an 03 V8 4wd, so full time 4wd with center diff lock. 4lo and center diff were working that friday and for about 5 minutes the following Saturday morning. Then they stopped and it wouldn't engage 4lo any longer. I gave up and started the trek home. Well, the 4Lo indicator light on the dash started flashing at me and wouldn't turn off. 4hi was still working fine so I was able to get home without issue.

I get home and Sunday, I popped the cover off the actuator housing and have about 1/2 quart of gear oil dump on me. So, I knew the shaft seals were shot, or at least one of them. Ordered up new seals and o-ring and received them this past Friday.

Crawled under the truck today and pulled the actuator housing off the t-case so I could clean it up and replace the shaft seals and o-ring. Come to find out, the hole for the diff lock seal is cracked in 2 places and the "cap" that holds the o-ring in place is also broken. So none of that is going to help now, I have to replace the actuator. Yay me!

New actuator from Toyota, which includes the shafts, is part #3641060093 and has a MSRP of $1,364.

That actuator is used on the following vehicles per Toyota:

Toyota 4Runner 4.0L V6 4WD AT LIMITED 2010, 2011, 2012, 2013, 2014, 2015
Toyota 4Runner 4.0L V6 4WD AT Limted 2016, 2017, 2018
Toyota 4Runner 4.0L V6 4WD AT SR5 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018
Toyota 4Runner 4.0L V6 4WD AT SR5 Premium 2014, 2015, 2016, 2017, 2018
Toyota 4Runner 4.0L V6 4WD AT Trail 2010, 2011, 2012, 2013, 2014, 2015, 2016
Toyota 4Runner 4.0L V6 4WD AT TRAIL Premium 2014, 2015, 2016
Toyota 4Runner 4.0L V6 4WD AT TRD Off-Road 2017, 2018
Toyota 4Runner 4.0L V6 4WD AT TRD Off-Road Premium 2017, 2018
Toyota 4Runner 4.0L V6 4WD AT TRD Pro 2015, 2016, 2017, 2018
Toyota 4Runner 4.0L V6 AT 2019, 2020
Toyota 4Runner 4.7L V8 4WD AT LIMITED 2003, 2004, 2005, 2006, 2007, 2008, 2009
Toyota 4Runner 4.7L V8 4WD AT Sport Edition SR5 2003, 2004, 2005, 2006, 2007, 2008, 2009
Toyota 4Runner 4.7L V8 4WD AT SR5 2003, 2004, 2005, 2006, 2007, 2008, 2009​

Aftermarket AISIN part is SAT-003 and runs $498 from RockAuto.

AISIN SAT003 4WD Actuator | RockAuto

Used ebay items range from around $200 to $400 from what I have found so far.

Still have to order the replacement but I thought I'd contribute to the thread with what I have so far. Hare are the pics of my actuator.

This was right after pulling the cover and having gear oil dump on me.


New seals and o-ring. O-ring is a Toyota part and the shaft seals are these - Shaft Oil Seals TC15x23x7


Center diff lock gears removed. The 4Lo stuff is below them. The center diff seal is the only one that leaked.


Actuator housing removed. The orange RTV is from a previous bandaid fix by the PO.


And the actuator where the shafts go into it and seal to the t-case.




4Lo gears and motor. These were still dry since the diff lock gears and motor actually sit lower when on the t-case. The metal gear is what engages the shift shaft for 4Lo and is in the "park" position from pulling the actuator off the t-case.


This is the broken shift shaft seal retainer/o-ring retainer.


I didn't notice the cracked housing until I had cleaned up the empty housing and put the new seals in place. New seals and o-ring still won't fix this leak and explains all the orange RTV that was used.


All I have for now. Looking for a replacement actuator now and will have to wait for that to be delivered.

 

While I'm waiting for the new actuator to get here, I decided to finally repaint the hood on the 4runner and bring the black center all the way to the leading edge of the hood. Looks better. Still need to do the grill in black but I need to get some more paint first. Can't drive the 4runner but I can at least move it around in the driveway and garage without loosing gear oil out the back.



First time I painted, I didn't go down far enough and it bugged me. Black pinstripes on the paint edge will go back on in a few days after the paint has dried.

 

Hood and grill painted. Still not sure if I'm completely happy with the hood. Maybe needs to be a little wider on the leading edge. I did follow the hood lines tho. Or maybe I should have stopped and left body color right above the grill. Oh well. It's still better than before.

 

Ordered up a custom plate for the 4Runner today.

 

what I have noticed dealing with those front diff 10mm hex bolts is #1 yes the are in there tight, breaker bar plus pipe cheater bar needed #2 take a hammer and hit/pound the 10mm hex socket deeper into the recess of the plug this way you wont strip the inner part out, if you don't pound it in deeper than just sticking it in by hand those plug points will start turning and strip that bad boy right out, now you really have a situation

 

Did that, still stripped it. Hence the welding of a sacrificial one. I have Lexus plugs arriving today or tomorrow for when I change gear oil again so it will be a non-issue going forward.

 

good part is if you get the hex bolt out once they usually wont give you any problems again

 

Especially when you coat the threads with anti-seize.

 

Well crap. Received the ebay t-case actuator today. Broken mounting tab and there are only 3. So it's all but useless. Waiting to hear back from the seller now.

 

Bummer you are AWD, I have my whole Tcase, Tcase motor and ADD sitting in the garage collecting dust.

 

I'm thinking about a possible FJ case swap from Rock Solid Toys, which would involve swapping the front axle for an ADD one from a Tacoma. I would imagine that the ADD axle from a V6 4runner would work as well. Gotta get the current one working again before I start worrying about all that tho. Need to be able to drive the 4runner since I have the Tacoma sold now.

 

If you are going that route you are better off not using ADD and using the non-ADD tube that (I think) you already have.

If you have some time, the FJ swap will probably be cheaper than the actuator issue, you can get a case for $300 or less.

 

Hrm, interesting. I only looked at the offering from Rock Solid since it comes already twin-sticked and the ADD front they told me is needed to be able to run 2wd on the V8 with the FJ case. They want $2250 for the whole setup.

 

You can do the twin stick yourself for a few hundred, most are of the opinion that it isn't really necessary and I tend to agree now that I have 2 lo on the Atlas. 99.9% sure you don't need the ADD with the FJ case as most are getting rid of the ADD at the same time they install the FJ case.

 

That's with the AWD V8 front axle? So the front axle would stay engaged all the time like that, even in 2wd. That's not a bad thing necessarily but would be added wear still and the front driveshaft would still be spinning. The idea of going with the ADD axle is to be able to truly disconnect the front axle from the system when in 2wd like what happens when you are in 2wd with the V6 4runner or on the Tacomas.

I see the twin stick kit for the FJ case from Front Range for $187. Not bad. Going to have to look into the FJ case swap that other people have done first. Was looking at the Rock Solid setup since it has everythign worked out and is essentially plug and play.

 

DISCLAIMER: RockSolidToys was a scammer and is no longer in business. Some of the information that was provided was good but the info about replacing the front axle was totally bogus. The OEM 4runner V8 front axle can be used and you don't need to replace it. Further details later in this thread. Also, running the FJ tcase with the full-time front axle WILL NOT DAMAGE THE FJ TCASE.

This is what Rock Solid told me about why they swap to an ADD axle: "Some people use the V8 front diff but it's full time operation and will cause premature damage to your FJ manual case when used in 4wd all the time. "

And, if the ADD diff from the FJ or Tacoma is anything like the ones on 1st gen Tacomas, they are actually a little beefier because of the ADD. So not sure why people wouldn't want to go with ADD or keep what they have. I will still be driving this thing on the street so will want to be able to completely disengage the front axle via the ADD.

 

4Runner body lift showed up today.