Groan sound when A4WD activates

[sispy]

Hello, on my 03 Expy there is a groaning sound that lasts for less than a second when activating the A4WD, the system keeps working fine without any noticeable sounds. Any comments will be appreciated.

Thanks.

 

[ELVATO]

I don't have 4WD on my Expedition, but when my parent's F250 is switched into 4WD, there is a groaning noise. I think it is completely normal, as something(not sure what) is engaging.

BTW, what part of Orlando are you from?

 

[sispy]

I used to have a 98 Expy and didn't make any noise (that I was able to notice) when the A4WD engaged. That's why I'm concerned with this weird noise. I live in the area close to Florida Mall.

 

[Sawyer]

My 2003 expy makes kind of a "clunk" noise when the A4WD engages. I thought maybe is was due to moisture or lack of, I am from Colorado and it seems to make the noise when I have to go thru mud vs. snow.

 

[ELVATO]

Ah, I see why you are worried. Maybe you could take a video so that we can better hear what you are reffering to. Same with the AC sound.

BTW, I live on the other side of town, close to UCF.

 

[green03]

depending on how fast i am rolling mine makes a clunk/rumble both when I switch to A4wd and then going and coming out of actually using it when it gets slippery.
Matt R

 

[AvroAero]

Well mine is only A4WD or 4WD so I can't switch between the two. But if you mean that the 4WD is groaning when the actual fourwheel drive is activated, meaning power is going to all four wheels. It may be normal. Going into four wheel on Expies on ashfault isn't the best idea. They don't have limited slip diffs, so when the front engages the two wheels are locked in sync, thus when any turn is done it stresses it since one wheel may turn more/faster than the other. On a slippery surface like snow, grass, or sand its unnoticeable since the wheels can slide without stress. Going from 2wd to a4wd shouldn't make any noise i think, since it just electrically monitors the traction to kick the 4wd in incase. as far as i know, mind you im always A4WD. Sucks sometimes.

 

[Karl in MN]

This kind of sounds like an issue I had with my 03 when I first got it. There was a TSB from 03 calendar year related to this.

Once I had the TSB performed switching to 4Auto is without any sound/noises at all.

The noise is from the front half shafts turning different directions. Once 4Auto is engaged the half shafts are forced to turn the same direction. The clunk is the one half shaft reversing direction and coming up to speed. The TSB called for adding some type of "S" spring or clip to the front differential to force the half shafts to turn the same direction when in 2WD.

4Auto should not produce a noise when it is activated.

 

[sispy]

Thank you everyone for your comments. Thanks Karl, that makes sense, I'll check that TSB.

Frankie

 

[johnnystar]

Is it a problem to put it into 4wheel when moving? As a guy who had the locking hubs on his 85 big old bronco & f250, i still to this day do not engage 4wheel of any kind when in motion, in any vehicle..
Not sure if it matters on the newer stuff, but i guess out of habit, i remain this way..