06 Tundra 4x4 System - LAST RESORT

Good Day Folks,

I write to you on my last leg... I'll try to make this brief but I would SINCERELY appreciate anyone's expertise on this matter.

First, I wrench on the side - nothing major but I'm definitely more competent than the "average joe" so I've read all the forums, watched all the videos and I'm stumped.

The meat and potatoes... 06 Tundra limited double cab 4x4 159k - I love this truck. Bought it with a 4x4 issue and I've spent the last 2 months trying to figure it out. Previous owner told me "shop said they would need to drop the Transfer Case and quoted me $2200"...

So I assumed it was the TCase actuator (very common) and ordered an OEM Toyota part because I love this truck... Installed and still the 4 HI light just flashes.

Next step: OEM Front Diff motor, changed front diff fluid, and sealed the new motor. I'm $900 deep in this thing with no results.. Doing the work MYSELF.

So I jack up the rear end, throw it in 4 high and nothing happens.

BUT - When i turn the car off (as the 4hi light flashes) I can hear my front diff motor shift... then my 4LO light flashes (without touching a button).

So I get out of the truck and jack up the front end and I can turn the tires by hand and the front driveshaft will spin... but no 4x4 and flashing 4Lo light.

I hit the 4Hi button and it shifts back to 2HI. So I can only get the front diff to move into "4x4" (which really isn't 4x4) when the 4hi light flashes and I immediately turn off the truck.

I've read the forums about driving forward and back etc but my truck will not engage, that light just blinks and blinks. I can hear the Tcase motor shifting when I select 4Hi so I'm assuming it's working, after all it's a brand new OEM... I've read that maybe the position of the TCase motor shaft / gear might be the culprit?

Any idea on where additional electrical components could be? New sensors on the motors but maybe under the hood somewhere? I'm truly stumped, my truck is going in for an airbag recall next week and I'm going to see if they'll look at it but it will be a cold day in Hell before I let a STEALERSHIP work on my truck lol.

Thanks for reading and for any insight you can provide. - Also if you want I can take a video of the sounds / processes and what happens when I hit the buttons etc. Thanks so much!

 

When you say front diff motor, do you mean the front diff actuator? Or are you referring to the differential as a 'motor'?

 

Hey Nick, thanks for the reply. I’m referring to the front diff actuator when I say “motor”. I know the front differential is not a motor lol! Sorry for the confusion

 

Paging @empty_lord

 

My guess is the 2 actuators are out of sync. If you can remove the plastic cover over the motor portion of the actuator, you can see where it sits. I can’t quite remember, but IIR, the xfr case actuator rotates clockwise to engage the front drive shaft.
At the same time, the front diff actuator has to rotate clockwise as well to engage the front wheels. I only figured this out by getting the truck off the ground and playing with both actuators until it worked the way it was supposed to.
I don’t have access to Alldata.com any more, but there was a fantastic illustration that showed the hocus pocus and how it worked.

hope this helps..

 

sounds like the issues in the transfer case.. alot of the t case actuator failures ive seen will shift into 4hi when you key off if you cant get it to go while blinking.. if i had to guess maybe the actuator was put on and the shaft got bumped and now it wont go into 4hi? hard to say without having my hands on it

 

Thanks guys, again both front Diff and Tcase actuators are brand new OEM. Could they still be out of sync?

It shifts when I turn the key off, but it still isn't really in 4x4 as I tested by jacking up the rear end.
Is there a way to test/ sync both actuators? I don't have any help at the moment, but I can do most things myself.
Should I pull the Tcase actuator off?

Thanks guys

 

Are you working with a service manual? I would start from scratch with the actuators, remove and reinstall per the manual.

 

I don't have one, but I can check my glove box and see if one's in there.

Does anyone have one? or a PDF? Thanks in advance!

Nick

 

Here you go.
https://drive.google.com/file/d/1ig1nDAjgXtsqQ5nJTTR_aLAlJsCCwXg1/view?usp=sharing

 

have you tested/replaced the actuator sensor on the transfer case? that sounds like a possible culprit if your transfer case motor is operating. Try unplug the sensor and see if it changes anything.

 

^^^ This...

Get the truck completely off the ground, put it in neutral and when you spin the front drive shaft, what else is moving when you have de-selected all 4wd options?

If the front wheels are turning with no power on, unplug the front differential connector after you kill power. Then turn the key to accessory and activate 4wd and reconnect the connector to the front diff. Spin the drive shaft (while still in neutral) by hand a bunch and this should sync the actuator to the switch position.

If the front wheels are not turning when you spin the front drive shaft, but the rear drive shaft is spinning, then do the same procedure with the transfer case actuator.

De-select all 4wd options, kill power, disconnect XFR case actuator, turn key, activate 4wd and reconnect connector. The idea is to get the actuator motors to sync with the 4wd ECU and push button position.

I sincerely hope this all makes sense...

 

Good evening and thank you all for the advice, I have finally figured it out - to God be the glory.

When installing the transfer case actuator, the shaft was out of place so when it “shifted” it wouldn’t quite get it all the way to 4x4 high. So I put the housing on, moved the shaft to the furthest point back while it still being in 2hi, and Inserted the gear.

When I hit the button it threw it right into 4 hi and then sent the signal for the front diff to do the same. Pretty sure my front diff was doing fine, but I guess having a new OEM one isn’t the worst thing. Frustrating 3 months but I feel like I have a new lease on life...

Tubdras till I die!

 

So it was out of phase. not clocked correctly. Thanks for reporting back! It's nice to see people report back on the root cause. I see too often in forums where people invest time with helping, and then we never hear back from the OP.

 

Great to hear this Nick! Put a checkmark in the win column..

 

Hello Festerw, I've been looking for the longest for this Manual, thanks so much for putting that here, now I can get to work!!