Gear 4x4 engaging sound

[hierarchize]

I have a 5.4L 3v 2010 model, I have been having this 4x4 trying to engage automatically, its trying to engage and the sound is horrid, screeeching metal noice , comes on and off after I give a little acceleration,anyone know what’s the reason? Did anyone have a similar issue? And the solution..


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[Mystify]

I have a 5.4L 3v 2010 model, I have been having this 4x4 trying to engage automatically, its trying to engage and the sound is horrid, screeeching metal noice , comes on and off after I give a little acceleration,anyone know what’s the reason? Did anyone have a similar issue? And the solution..


Sent from my iPhone using TapatalkVacuum line.


I had mine do something similar. Was a Crack in the pass side vacuum line.
4WD is vacuum operated. When the engines running vacuum is "on" and pulls the IWEs away from the hubs. Every time you touch the accelerator, vacuum in the lines drops because it leaks out the crack in the line . When that happens the IWEs try to engage with the hubs.

I pulled the vacuum line off the 4wd actuator on tbe brake booster and hooked up a hand vacuum pump. It didn't hold vacuum like it should have . I then hooked up a smoke machine to locate the leak location..

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[hierarchize]

Well I did that check and it works , just found out the sound comes from the transfer case .. 500$ work ahead.


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Vacuum line.


I had mine do something similar. Was a Crack in the pass side vacuum line.
4WD is vacuum operated. When the engines running vacuum is "on" and pulls the IWEs away from the hubs. Every time you touch the accelerator, vacuum in the lines drops because it leaks out the crack in the line . When that happens the IWEs try to engage with the hubs.

I pulled the vacuum line off the 4wd actuator on tbe brake booster and hooked up a hand vacuum pump. It didn't hold vacuum like it should have . I then hooked up a smoke machine to locate the leak location..

Sent from my SAMSUNG-SM-G930A using Tapatalk

Thanks


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[DontDriveAChevy]

Well I did that check and it works , just found out the sound comes from the transfer case .. 500$ work ahead.



Be sure to change the fluid in the transfer case whenever it requires. Most people NEVER change the transmission, differential or transfer cases. That's REALLY BAD. They all require periodic maintenance and it's not necessarily cheap. But the good thing is, once you do it, you often don't have to do it again for a good 40,000 to 100,000 miles depending on the fluid that you put in.