So, I have a 05 navigator that is in the shop for a whole mess of things. One of the issues i have is that when put into 4x4 high or when 4 wheel engages in auto mode i get this hum from the front end that gets louder as speed increases until around 40 or so then kind of goes away. There is also a very slight vibration you can feel in the floor. Dealer says it's normal which i don't think it is. They said they ran it on the lift and it made no noise. Noise is only on acceleration so to me it sounds like a bearing or worn pinion because it's only with a load. Does anyone hear any noise when engaged in 4x4?

 

No one has ever put their truck into 4x4 high?

 

it could be the CV axle

maybe its the rubber to rubber contact that make that noise?
my cvaxle is craked and have to replace not sure if thats why my make noise?
or could be a wheel baring tho, most suv/truck have that problem how many miles ur truck got?

 

i'm around 66k on her now. It's only when 4x4 is engaged though. 2WD makes no noise at all.

 

well i dont think you should worrie, my truck kinda vibrates too, but why would u need 4x4 in fast paste? maby the transfer case need some new oil, or something.

 

just doesn't seem right for a $50k truck to make all that noise. why is it the dealers are loaded with used 05-06's until i need one?

 

Mine makes it when the 4 wheel drive is engaged. Never had a problem out of it ever.

 

Not gonna be wheel bearings or cvs if it doesn't do it in 2wd. Maybe the t-case. Are these cases chain driven like rangers? If so, maybe the chain needs adjustment.

 

i rode in my friends 04 expo to see if his makes the noise and his does but very slightly, not nearly as loud as mine. I'm going to try changing fluid in the diff and transfer and see what happens

 

When a dealer tells you its normal, it means they don't want to spend the time to trouble shoot it. Take it somewhere else.

 

The problem with that is i only had 2 weeks left of warranty when i dropped the truck off. They had the truck for a month straight, crazy i know. The only major repair they did was the phazers which im very happy about, the rest were little things that should've been finished in a day. I changed the oil in the diff and transfer and the noise is very slightly subdued but still quite noticeable. Gears looked fine in the diff, could be a bad bearing or something.