Hello all,
I am a new user but have spent many hours on this site finding answers to questions I have, or more importantly, mods to do. Now I have a question that I can't seem to find an answer to. I have a grinding/snapping/popping noise coming from my front end. This primarily happens when I'm in 4x4, but sometimes when I am making a corner in 2x4. I first thought it may be the cv axle, but decided not because of it not happening much in 2x4. I read that it may be the 4x4 actuator and I used my phone to record a video of it while I shift in and out of 4x4 (I was doing this alone so no one else to look). The actuator moves very little the first time, and isn't noticeable after that. So that makes believe I have one of two problems, the actuator is bad, or I have a crack in a vacuum line causing it not to build pressure. I should note that the 4x4 does still work, so that should rule out the solenoids. This is on a 2001 with the 4.6.

Thanks in advance and I hope to learn more by being a member of this site!
Ryan

 

Sounds to me like you've already got a good handle on it. I would agree that it sounds like a vacuum leak. Can you reach up and make sure that it is making a full engagement and/or disengagement? The reason I ask is that it's not a big swing to engage it anyway, so I would check to make sure it's not fully reaching it's desired destination before looking too deep into it.

 

Are you talking about the swing of the lever on the front diff that is moved by the actuator fed by the vacuum lines? That does not move hardly at all, especially after the first time taking it in and out of 4x4. I don't think it pertains to this issue, but when I put it into 4x4 HI, the low range light also comes on. I recently replaced the position sensor and it worked fine when I first replaced it, but now the low range light comes on and I'm hearing that grinding noise. It is a MSOF if that helps you.

Thanks

 

Well, that's where you need to start. Whether it's the position sensor, or the GEM, that needs to get resolved first. Does your windshield leak?

 

The windshield does not leak. How can I tell if it's the GEM or position sensor?

 

So, I started visually inspecting my vacuum lines. Nothing to be seen. There is a black tube that goes who knows where, that comes off where it is teed to the red line off of what I assume is a check valve that is broke. There are the red and blue tunes that run to the front diff, as well as the larger rubber tube. Right where they all connect together near the battery, about halfway to the solenoids, the connection in the big black tube is broke. I assume this is my problem. I will be taking my truck back to the auto shop that installed my headers because they would have broken it when they pulled the tree holder out of the fender liner. If you believe otherwise let me know ASAP before I go chew their asses on this.

Thanks

 

My mind is drawing a blank. Do you happen to have a pic? (of the black tube)

 

No problem...




This is where its is broke (black tube below the red and blue lines)





This is where it goes into the front diff (on top of axle coming in on the passenger side)





This is where the smaller black tube is broke. The tee you see has another black line coming out of it, and a couple more inches down that line is where the red line tees in.

 

Good hell... they caused a lot of mayhem in there. Yeah.... that's not good.

 

I don't know if they could have broken the small line, and that is pretty brittle anyways, but for sure they broke the big one. What does that line do?