khann

I guess that manual for T4 G3 was written in 1996....and updated later. And Toyota wanted either to make money on service of Tcases or just didnt put such simply to diagnose problem. Besides there are some points that said wchich switch is on/off and when.

khann

Yes changing both front assy act and tcase assy act are not very complicated in 3gen 4R.

Testing front act in 4R is quite simple without removing (dunno if same for FJ) - move front of vehicle and test vac lines (using vacuum pump (20 in/Hg vac is enough; or big syringe with pipe) You should hear 'click', front wheels are getting free or locked, and state of switch is changed after (multimetr will tell You the truth)

toyotapartszone is my favourite shop (prices at 70% of rest) and they send to EU

khann

I did same with similar problem but unfortunately previous owner has dissembled actuator of tcase and after that never been working this part is not possible to fix (or very hard).

I bought new one (but didnt fit - photo - known problem with Ltd version 96-99 - buy actuator for 99-00!) second one fit and my 4R is 4WD again!

Simann

Khann, very good info and thanks for the picture!

The mail will be running tomorrow so I should get my switches in, as well Toyota stated my sensors will be in as well. Replacing all 4 of these should either work, or all point towards my actuator needing replaced. Either way I am saving $1000 over what the dealer quoted me to repair it. (Bought the truck this past Friday off the lot with it stuck in 4WD high. The dealer (a Dodge/Jeep dealership) quoted me $1200 to fix the problem which was thought to be an actuator, but after I skimmed this thread I new I could fix it myself for far cheaper.

I will update later this week

khann

So Simman situation similar as mine welcome to the club. Most problems with ADD is because of not using it! Its good idea to shift as much as possible before exchange of actuator.

'Every week 4WD' is key point

Simann

Khann,

So I replaced one switch, but on my 2000 Limited 4runner it seems Toyota had both switches have different female connectors.

As well, I was an idiot and unscrewed the three 10 mm bolts off the Actuator head and the internal clock-spring litterally just fell out. I cannot get it back in either! So it looks like I will have to take the truck to a mechanic and have the drop the transfer case and replace the actuator. Arrggg

First pic is the sensor variation. Second picture is the Actuator clock-spring thing that I could not get back in so I just took it out and sealed the plate back up and drove it home. Pretty frustrated right now. I'm an very well versed self taught mechanic but this seems to boil my blood. I cant seem to find any resources as of how to exactly remove the 2000-2001 4Runner 4x4 transfer case actuator assymbly!!

Simann

Well I got it all back together and even replaced the front Differential actuator switch. Now the truck will go into Low gear as well as High gear but I just can't quite tell if its in 4WD or not.

khann

But does the 4WD tree blinks or goes lit-unlit (either4wd or 2wd)???
Transfer case actuator can be replaced without opening t-case. To change it You need to open small cap (traingle shape) -there will be a screw for locking this bolt. Another option with opening of tcase is changing this bolt as well.

drivin in 4wd gives harder reaction during drive on steerin wheel whilst 2wd is very soft in steering....

Simann

1) The light blinks. When I press the 4WD select button on my shifter knob the light momentarily stops blinking for approximately 3 seconds, then starts blinking again.

2) The truck definantly is in 2WD mode now, the steering is much lighter and when taking a tight turn the truck does not feel like its crabbing along on loose asphalt.

3) I actually tried to open that top triangle cap with the three small 8mm bolts. But I could not get the cap off, to be honest I did not try to hard. I figured Toyota designed that access cap for a reason. Good to know I don't have to remove the entire transfer case to change out the actuator!

4) I actually got the clock-spring thingy back in the actuator, miracle or luck. However, I am NOT sure if I got the alignment right. Supposedly it is set at "12-o'clock" ?

5) I have yet to test the resistence of terminals 2 and 3 for 2WD to 4WD actuation yet. I will do that tomorrow.

None of this is rocket science to me, I just needed to know where to start after replacing some sensors.

So far I have replaced ONE of the actuator switches, had to leave the other alone as I did not have a replacement for it yet as it had a different female connector! I replaced the front diff actuator sensor too. After doing this, the truck went back into 2WD on its own, I heard it "clunk" when I started it up.

So basically, after replacing the front diff actuator switch the truck went from 4WD to 2WD as well as 2WD low, but I can not go back into 4WD at all.
I'm really leaning toward it being the front diff actuator itself.....what do you think?

khann

So the whole system is locked (i had exactly same!) reason could be now switch (front, or any swith Tcase or -worst- actuator tcase). You still can fell reduction on 4lo - but it works only for rear wheels now.

My situation was like this: actuator bolt was almost stuck (no using for years) and then sbdy started operating 4wd which lead to actuator damage - so my mechanic opened tcase and refreshed everythin inside to move softly (cost around 200$)

Exactly - toyota didtn tell anything about it it claims that actuator must be repalced (somehow) but there is a check procedure for working - no working actuator
Now it really hard to say. I had 3 used actu's but i(and my mechanic) was unable to make one working properly - combination: motor|spring|shaft|bolt|encoder<potentiometer>|swi thes is very unique mayby other yotatech users will be succes but most probably - find working one

This test i suppose must be done outside tcase with bolt inside (as on my photo) I was doing like this

system is quite simple and parts are disigned well but parts are very expensive Toyota Poland wants thousand$ for Tcas act while toyotapats.com only 800 bucks

it has diff conn probably not to mix signals either the shaft inside is different

Well now when You opened Tcase Actuator Id rather say there is a problem. Front actuator You can test with simple ohm meter (front switch goes on -off ) and some vacuum. Or to test it Just unplug switch from front and short wire it or leave open if no change - search the rest of system. In my case all swithes were ok. TCAct was f...* up

I hope this will help - also reading this thread and all pictures/diagrams helped me a lot to understand system.

Simann

PROGRESS:

Well, with the help of my brother (who is a computer/electrical engineer) we tested 3 of the switches I have swapped out thus far in the ADD system. All 3 switches were BAD. My truck is a 2000 with 138K miles and absolutely immaculate. I am the second owner, and apparently the only one who ever wanted to use the 4WD system!

All 3 switches original to the truck were non-functional by multiple tests with the multimeter. I also tested the new switches to concur function. So basically I have 2 more switches to order and put on to make sure its not the Actuator itself.

All in all, I still don't have 4WD, but even if I had replaced the actuator, the system still would not have worked as the switches were all bad!

khann

Thanks Simman - good to hear that You dont give up - Switches (as someone said here) sometimes can be set back to life using contact cleaner.
Keep goin!

Simann

Khann,

Yeah I know I could have cleaned them, but given they are 10 years old and more than likely filled with sludge (transmission oil) I would just rather replace them and not "bet" on having them gunk up again sometime soon and have to go through this whole guessing game again. They are a "wear" item.

I will update when I get the switches put in.

PS: I also made a nifty socket to pull the switches with the long wire harness off the transmission. Basically just took a 27mm socket and used a Dremel tool to notch out a rectangle so the wires could fit through and I could get the socket over the entire switch.

likkleBIT

Just need to say great write up. Wish I found this before disassembling and reassembling my transfer case last Saturday. At the moment my 4wd still isn't working and I think I am a step backwards in that I no longer hear / feel the clunk of the add trying to engage. I figure it's because my mechanic and I took apart the transfer actuator motor assembly and didn't puta it back in correctly. Just did the test on that (transfer case acuator) tonight and no movement. I only hear a click when the positive is on pin 2. When I get the electrical actuator sorted out I will definitely check the switches starting with the front diff.

Thanks again to everyone and I will update this thread as I get it fixed!

Oh, almost forgot... My vehicle is a 2004 Hilux 3.0l turbo diesel manual 1KZ with add and one shift on the fly 4wd button found on the hi-lo gear stick.

likkleBIT

Last night with the information i've learned in this form and a few other web searches i fixed my issue of 4wd not engaging for over an year and a half. Thank you thank you thank you all.

If anyone has an issue with the transfer case electronic actuator i may be of some assistance.

My rig wasn't going into 4wd and the stealership wanted to charge me USD$3,000 for a replacement transfer case. Long and short I ended up disassembling the 4wd actuator with my mechanic during a complete transfer case teardown (also after having purchased an incompatible spare from a junk yard). after rebuild it seemed we took a step backwards as there was no clunk as before. I therefore theorized that i had a problem with the ADD not engaging all along. I never had any blinking lights.

Last night i took off that little motor, opened it up, and played / tested different inset positions for the large driven gear referred to in the pic below. After a few tries while applying +ve and -ve to pins 2 and 3 on the actuator I was able to get the thing working right. Let it be known that the driven gear and the final gear that contacts the rod moves counter-clockwise to engage 4wd, so the spring need be set accordingly. It will take some trial and error though, but very doable once its looked at logically.



Whole process took me 2 hrs and i finally had 4wd, front diff engaging and all! seems sluggish still so i will be looking at the add actuator and switch to see if any improvement can be made.

I hope i contributed and helped someone with this info. Do PM me or reply to the thread if more detail needed.

And thanks again to the OP and all the contributors!

LIKKLEbit from Jamaica

Simann

Now THATS the diagram I needed!

What model/year truck do you have likklebit?

likkleBIT

I have a 2004 Hilux SR5 (KZN165R) with the 1KZ engine. Manual trans. One 4wd button on the 2H/4L shifter.

The diagram and more is from this forum thread: http://forum.ih8mud.com/80-series-te...tor-fun-3.html

likkleBIT

Simann,
This may help also. looks close to the position i aligned that driven gear in the electric actuator.

With the cover off and that spring gear setup out: hold the unit so that the worm gear is at 3 o'clock, and place the driven gear at 12 o'clock.

My driven gear looks different to yours and the one in the link below, but thats how i believe mine was set for it to work.

http://www.tundrasolutions.com/forum...ator-question/

Simann

PROGRESS:

Well I finished installing the last two of the total 5 sensor/switches in the system and the ADD still does not work. I am quite confident that it is in-fact the Actuator itself.

For the record, 3 of the 5 sensors/switches were DEAD. So, the $300 in sensor's I spent was not in vain.

Well, guess I will be ordering a new actuator. No use in trying to fix the one that is on there now. I will just use the broken one to disect and figure out just what in the heck went wrong and maybe get some better answers/pictures out of it for all of us on the forums!

-Jonathan

likkleBIT

Jonathan, are you able to test the actuator itself by placing positive and negative power to pins 2 and 3? If you hear no action the system is stuck. If you then take it off of the transfer box and have the driven gear out, you should get movement from the electric motor (cause its not driving anything). Have you done / can you do this test?