01-02' Transfer Case Troubleshooting

[Hardizzy]

I'm in the process of troubleshooting a stuck 4wd issue on an 02' T4R. I understand there are other resources, which I've read and is not specific to 01-02' transfer cases. I also have an 01', where I've swapped both the forward and aft sensors located on the transfer case actuator. My 01' is working fine with the 02' sensors, but the 02' still has the blinking lights. If drop it into neutral and press the center diff. lock switch, it'll engage and stop blinking. Both switches register continuity, so I'm know it's definitely not the switches.

I haven't pulled the two switches located on top of the transfer case. But, I suspect the transfer case actuator might be the culprit. That or the FR diff. switch mentioned in the thread I read: https://www.yotatech.com/f2/4wd-wont-disengage-99-4runner-ltd-131201/. I also can't hear the the actuator moving or at least attempting to move.

I'm going to replace the transfer case fluid (unsure when or if it has ever been replaced) to see if that'll solve the problem. I'm considering swapping out the transfer case actuators if that doesn't work.

I appreciate any useful feedback. Thanks!

 

[sidewinder1]

Hi Everyone,

My '02 4Runner makes some noise when running 50 km/h and above. I suspect transfer case is reason of such noise. I have recorded some videos with camera mounted under car.

https://www.youtube.com/watch?v=qOWspL2Jmug&feature=youtu.be

Does anyone have something similar? Is it an issue? Is my transfer case about to break or is it ok? If not, how did you fix it?

Transfer case is multi-mode + ADD, with center diff lock.

Thanks in advance.

 

[jgue467]

OP it may take several fluid drain/fills but try a couple/three before moving on to other tests. Have you checked the FSM for procedures and order of tests?

To Hardizzy - have you tried tightening the two bolts holding the TC dampner in place? Mine were loose (s/b about 28ft lbs) and caused a similar rattling at idle in gear. Luck to all! :cowboy:

 

[sidewinder1]

OP it may take several fluid drain/fills but try a couple/three before moving on to other tests. Have you checked the FSM for procedures and order of tests?

The FSM I have does not contain such tests - it only has procedure to check c.diff lock actuator and 4wd on-off tests.

 

[calimobber]

sorry about the 02 4wd issues, I just delt with similar problems and it took me forever since I was lazy.

Do you have the 4runner repair manual? its free online.

For me the first place's id check are the front diff actuator. Its very simple to check, if you read the manual its something like if pin 3-4 have continuity( meaning a volt meter on ohms will beep) and 3-4 don't its not connected. this tell you if its connected or not connected. You can also put the 4runner on 4 jack stands and see whats spinning. hit 4wd button and see whats happening.

You can also force it to shift by applying 12v to two pins( check the manual)

Once you know the front actuator is good you can move on.

You can check all 4 of the tranny position sensors making sure thats not the issue.

 

[calimobber]

I actually drove though water and got mud/water into both my front diff actuator and my 4wd actuator on the transfer case.


I ended up buying a used transfer case from a junk yard for $200 and just replacing it since its very difficult to replace the actuator itself.

 

[Hardizzy]

I'd like to report that I solved the issue after 3 years. A lesson for all to never give up! The old girl works 100% and was sold to a fellow 3rd gen enthusiast today. I wanted to update folks who might come across this thread in years to come.

As mentioned by [MENTION=68424]calimobber[/MENTION], removing the actuators are a total PITA. But, after replacing all of the sensors, switches, fluids, and computer, I decided to bite the bullet and pull the transfer case actuator. I had previously noticed that the vent hose on the transfer case actuator had become loose and tattered. Be sure to inspect your rig, snip the tattered end and re-attach and zip tie that sucker! If your hose is disconnected, there's probably a bunch of trash inside your actuator assembly.

The complete actuator assembly cannot be simply removed without disassembling the transfer case. However, the lower half is held in place by three 10mm bolts. Be very gentle when pulling the lower half. The gear will most likely be under load. You do not want to the tensioned "spring" attached to the gear to become undone. It can be put back together, but it sucks. Slowly pull the lower half until the load releases.

Here's what I found:
<a data-flickr-embed="true" href="https://www.flickr.com/photos/40107386@N07/49797827718/in/dateposted-public/" title="20190901_130203"><img src="https://live.staticflickr.com/65535/49797827718_fcba9c404d_c.jpg" width="600" height="800" alt="20190901_130203"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

<a data-flickr-embed="true" href="https://www.flickr.com/photos/40107386@N07/49798379051/in/dateposted-public/" title="20190901_130229"><img src="https://live.staticflickr.com/65535/49798379051_65875d2f52_c.jpg" width="600" height="800" alt="20190901_130229"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

The actuator stopped working shortly after I had purchased the truck at 173k. The vent hose must have been disconnected for years. The lower half of the actuator was trash. The armature was completely rusted and seized.

If your truck stopped working in AWD or 4WD, you can manually turn the gear to unlock the center diff and place it into 2WD. I believe you have to turn it counter-clockwise to place it into 2WD. I might have forgotten, so check your tire rotation. Your truck will need to be on stands in order to inspect the rotation of your wheels. All of your switches should be set to the 2WD and unlocked position.

I was able to find this beauty at the local pick-n-pull:
<a data-flickr-embed="true" href="https://www.flickr.com/photos/40107386@N07/49797821728/in/dateposted-public/" title="20200420_125700"><img src="https://live.staticflickr.com/65535/49797821728_c718b4a674_c.jpg" width="600" height="800" alt="20200420_125700"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

I cleaned the old Toyota grease and put some electrical contact grease I had on hand. I carefully aligned the lower half and shimmed it into the gear portion. Don't try to force it in, it should fall into place relatively easily.

Here is what it looks like if the gear is removed. Try your hardest to leave the gear attached if it is not damaged. Note the tattered end of the breather hose and the sheared bolt--be careful if you live in the rust belt:
<a data-flickr-embed="true" href="https://www.flickr.com/photos/40107386@N07/49798479496/in/dateposted-public/" title="20200406_120721"><img src="https://live.staticflickr.com/65535/49798479496_e0c81894b3_c.jpg" width="800" height="600" alt="20200406_120721"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>

Re-assemble and inspect that wheels are still in 2WD. Again, the gear is under load and can slip into the locked position when the lower half is being re-attached. I disconnected the battery for a few minutes to reset to computers. The flashing lights should come off. While your truck is still on the stands, turn it on and inspect operation.

I'm not sure if this can be applied to trucks without the multi-mode transfer case. Preventive maintenance is key folks. Inspect your breather hose on both actuators! I hope this helps someone.

 

[fourfive]

I'd like to report that I solved the issue after 3 years. A lesson for all to never give up! The old girl works 100% and was sold to a fellow 3rd gen enthusiast today. I wanted to update folks who might come across this thread in years to come.

Thanks for the follow up. No doubt I'll probably have to revisit this at some point.