Meep dog

06 4x4 190kmiles. The 4wd shifter is on the floor but maybe that's normal... When I'm 4hi and moving, you can hear a light steady rhythmic metallic noise almost like a chain or gears grinding.
I changed the transfer case fluid and the noise is still there. I've only had the truck for 10k miles. Is this a normal sound or something I should be more concerned about?

needsmoarturbo

Does it make the sound in low range as well?
If it has the same iwes as the electric 4wd models I'd suspect one of them of having an issue and not engaging correctly or fully.
if you want to inspect then you can put in 2wd raise the front wheels with the truck not running the front wheels should not rotate. With engine running they should rotate freely. At least this is how the system with a **** on the dash for 4wd works.

Jimboy

A word of caution -You may or may not be aware that 4-wheel drive should not be engaged on roads or hard surfaces, it will damage the system.

Your issue appears to be full engagement of the iwes as Needsmoarturbo stated above.

Meep dog

I swapped out the IWE's as well as both CV axles. The noise is still there. The only this left is the front differential I guess.

needsmoarturbo

And did you verify there is vacuum at the hubs? New hubs still won't work correctly if the vacuum system isn't working.

fang2015

Have a 2007 4x4 5.4 (bought new) and the transfer case tends to rattle some in 4 hi. It's been doing it for at least 10 years and the truck now has over 170,000 miles. Changing transfer case fluid makes no difference. It seems to be more prone to rattling in the summer than winter. Haven't worried about it for years. This truck is a strong 4wd vehicle with immediate engagement and release on the hubs - never had an issue. It does get driven frequently throughout the year in 4wd.

Meep dog

I replaced the stock hubs with the OEM fix that are permanently engaged. The CV axles spin in 2WD