(Help!) 4x4 slight grind and not engaging

Hey all,

3 weeks ago I finally bought and replaced my rear transfer case actuator. This effectively solved my 4x4 issue (stuck in 4x4, would not shift out) as the rig switched mechanically smoothly through all 3 4x4 modes after the new part was installed. However in 2Hi the dash indicator kept blinking while it was in 2hi continuously. last week miraculously the blinking light in 2hi went away.

However, now when I switch to 4wd (while driving) I hear a slight whirring or grinding noise that's definitely coming from the front end, possibly the passenger side. and the 4wd will not engage, just flashed on the dash. It does beep when i attempt to switch to 4Lo, but only about 75% of the time. Is it possible that the front diff actuator burned up while it was stuck in 4wd for so long before i figured out that I needed to swap the tcase actuator?

The Tcase actuator is functioning, if you cycle the 4wd system without the rig running i can clearly hear the rear actuator working and shifting. Front Diff guys - help me out!!

 

You have the worst kind of luck.
It sounds like you may have blown the gears on the ADD.

Note that the ADD isn't actually part of the front differential, its a disconnect on the passenger side shaft. The differential is towards the driver's side.

Try to put it in 4wd and then lift the front, it should be fairly obvious if the shaft is connected or not by spinning the wheels.

 

yea, I feel like that is the issue as well. At least this is a much cheaper fix for a new actuator than the T case, which seem to average $500 used.

 

Lots of good info here about the front actuator :

https://www.tacomaworld.com/threads/how-to-trouble-shoot-4x4-actuator.263525/

Before you go and buy a new one open it up and see if you can fix it.

 

Yep that's my plan. I just wanted to crowd surf that is was the ADD. which was my suspicion as well.

 

Well, think i got it. I opened up the front ADD and soldered the known prongs. When I went to reassemble, I noticed the little gear only has half its teeth!

So I think in reality I actually fixed the motor, because after a few tries it does go into and out of 4wd (dash indicators all normal; off then solid) but it only works every other ish. Which tells me:

1: I did actually fix the motor which wasn't working.
2: I need an new ADD anyways because of the broken gear.

To EBay!!

 

With any luck, you might be able to find a broken ADD (i.e., bad electric parts) that still has good gears in it.

 

For the $200 on eBay, I'm happy to buy a brand new in box motor and install the new one.