Four Wheel Drive not engaging/flashing indicator light

[msj1542]

First of all, I am brand new to this forum so I would just like to say hello all!

Okay, now down to the real business. I have a 2003 TB with 112k miles on it that has had an ongoing 4x4 issue for the last year or so (Ive just put off digging into it until now because up until this last weekend I havnt had a real serious need to use it).

What it is doing is a couple different things, so I can not pin down exactly what needs to be replaced. To start with, 2 hi works perfectly fine and when I switch to A4WD/4Hi it appears as though it is working just fine - the indicator lights show it is in the correct mode and both the transfer case actuator as well as the front differential axle actuator sound to be working too. However, when driving on snow it is obvious that the 4hi for sure is not actually engaging (even though the indicator light indicates that it is engaged), and the A4WD seems to work to some extent but acts a bit more rough than I remember it being a few years back. When I put it up on a lift and cycle between the three modes with the tires idling, the fronts spin in A4WD and 4hi, but can be easily stopped with your foot (and there is a very faint gear grinding noise from the front dif, but doesn't sound loud/damaging, just that something definitely is not correct). The 4 Low also seems to work okay, at least when I switch into that on dry concrete (as well as the lift) though I have not had much of a chance to test that in slippery conditions to confirm 100%.

Also, intermittently the indicator switch does its diagnostic at vehicle turn on, where the mode light flashes for about 30 seconds then shuts off completely, but this only happens every once and awhile, more so after I have tried using the 4WD the day before.

I will also add that I read another thread on here earlier this morning by someone who mentioned removing the front diff actuator, take it apart to clean it and re install it. Well I tried that, it did not fix the problem, and now there is more of a grinding noise in the front dif than there was before I cleaned it, which I think is caused by my putting the actuator back together and the throw distance of the actuator vs. the motor limits not being exactly as it was before disassembly. Just thought I would mention that in case it provided a bit more insight as well.

I feel like I could probably fix this problem with a lot of trial and error, but I am trying to avoid throwing money away at new parts that are not in fact bad and will not replace the problem lol. I will much appreciate any help that anyone can provide in pointing me in the right direction to get this fixed! Thanks!!!

[darring70]

Looks like the transfer case to me

[msj1542]

When you say it looks like the transfer case, do you mean the actuator at the TC or the TC itself, could you elaborate a little bit? The only reason I semi ruled that out to begin with is because the front is still obviously spinning, and the 4 Lo does work, so it led me to believe it is connected to the front axle disconnect. Thoughts??

[darring70]

The TC by it self, the TC function is to move the gears to go from 2 to 4 back and forward, if is not going back to 2 is because is getting stock, that happen to me before and I replaced the TC and is working with out problems, it is very easy to replace it, actualy you can find the video on youtube

[msj1542]

Oh, I think you have have misread my original post, because it doesnt have a problem going back into 2 from 4, the problem is when I put it into 4 hi or A4wd everything acts as though it is going in (the lights on the switch illuminate for the correct corresponding mode, and both actuators sound as if they are working) but the front end is not engaging, or at least engaging fully (because they do spin some, but dont have any torque because you can stop them with your foot when up on a lift). Is that how you understood it? and if so, does that symptom still sound like the TC??

[freddyboy61]

Two questions;
1) When was the last time the TC fluid was changed? Should be done every 50K
2) You said you had the front disconnect actuator out, did you take the spline disconnect assembly out of the differential and examine it?

My opinion, if the TC fluid has not been maintained, that is where the problem lies.

[Loverotties]

is the fluid full?

[msj1542]

Does the TC fluid need to be changed even if the 4x4 is used about 2-3 times a year? But no, I have not ever changed it, myself at least (that wasn't even a thought of mine to change that, to be completely honest. I would have assumed that a mechanic would have advised me of that when it came due, but maybe not). Therefor, Loverotties, I am unsure if it is full or not lol. You say you think that may be where they problem lies...does that mean that you think that something is damaged due to that, or that the fluid is low/old so it isnt working correctly due to that, kind of like an auto tranny does?? (could you tell me the easiest way to go about changing it?)

No, I did not take the spline out, I wanted to get a more definitive answer as to what may be wrong before I dove into that. I had read somewhere that the thruster washer could be damaged so I was semi thinking that may be my issue, per they symptoms that people said that causes.

[Loverotties]

Fluids have to be changed!it breaks down and get dirty just like any fluid!

[msj1542]

So hypothetically it is the fluid, do you think changing it alone will fix it, or are you implying that because it is past changing it that it has damaged something??