Noise in 4wd when on Auto4WD

[Randy Whistler]

Generally, I run around town in 2wd this time of year. Very little snow or ice to worry about in Kansas in June. Every once in a while I will operate the Auto4wd selector - more than anything, just to play with the buttons that don't get played with often, but as a test as well.

I have noticed that when I'm in Auto mode, there seems to be some sort of slight squeaking noise when moving. Not a loud squeal like one might expect from brakes or a bearing going out, but more like the squeak you hear when the idler bearing is getting ready to go out, and not continuous. It's only when rolling, and just a little squeak-squeak-squeak. I should note here that I have only observed this noise when at a non-road speed. I've heard it when driving through a parking lot at lower speeds, like 15 or so.

I've not yet dug in deep, I just noticed this(once again) yesterday when gliding through a lot, so I cannot say where it's coming from yet, or what it does at speed, etc. Does this sound like something anyone's run across before? This truck sat abandoned for a short period of time, so lack of lube is something that comes to mind. Everything else on the truck seems to work quite well, and that makes me hopeful that this new, fun little noise to chase down is a relatively painless issue. . .

 

[M1Gunner]

Sounds like you could start with the u-joints to the front drive shaft

 

[Randy Whistler]

Little more info. Gunner, I agreed, that's what I thought it could be as well.

I put the truck in Auto 4WD and drove about a bit. There is definitely something not playing well somewhere. The first thing I noticed was that, when turning, the front tires were "scrubbing" when turning. There is a noticeable drag when in auto 4wd when turning. I think it may be odd when driving, too, but not enough testing yet to say.

I should say that, when turning in 2wd, I notice that it seems to drag a little when turning sharp - at the lock.

Hope all of this helps. I know there is a problem there, now, and all I have to do is find it. . .

 

[swathdiver]

Randy are you turning in 4Wd on a hard surface like pavement? They'll all scrub and protest doing that. Have you crawled under and check the transfer case and differential fluid color and level? Check the u-joints too like Jason said.

 

[PG01]

Auto4 you’re basically locking in the hubs like trucks of old but not actually putting it in 4wd. When computer senses slip in a rear tire it will send power thru transfer case to front. Technically there should be ‘very little’ to no noise or ‘scrubbing’ in auto, even on dry pavement.... 4hi yes, 4lo def.....auto no. That said, if you feel drag...in 2wd... however little..... id say you got a front hub going out. Check fluids like @swathdiver snd ujoints like @M1Gunner ssid but i think one of yer hubs is on its way. My 2cnts

 

[Randy Whistler]

Randy are you turning in 4Wd on a hard surface like pavement?

Yes, that's exactly what happened.

Auto4 you’re basically locking in the hubs like trucks of old but not actually putting it in 4wd.

And that answers that! I completely understand now. I am familiar with the "trucks of old" 4wd set ups, had Jeeps and Land Cruisers that you had to manually lock the hubs, so the locking of the hubs makes sense to me. I just never had a vehicle that had "Auto 4WD" before. Answered that one.

I'll crawl under this weekend and start checking things out. Are there any tell-tale signs to look for on the front hubs & axle? I had wondered about the lube level in the diff - haven't had a 4WD vehicle for some years, and never even gave it a thought. . . bad, bad boy!! If it is a hub, is that expensive and/or hard to change out? Anything to be wary of?

And thanks to everyone offering help! Having forums like this, where people are helpful and willing to offer suggestions and advice, are few and far between, and I'm tickled to have found this one.

Thanks again!

 

[Randy Whistler]

OK, a little follow-up on this fun issue. I've noticed a slight "tic tic tic tic tic" noise coming from the driver's front hub, at slower speeds, usually around 10 or less. It's not loud nor can it be felt, it's just there. It's not unlike tapping something lightly on a desk - louder than most clocks tick, obviously, but not the "clunk clunk" of a half-shaft going out. This leads me to believe this is the bad hub.

Am I on the right track? Is this something horrid that will explode momentarily, or is it just something to repair soon? I doubt I'll use any 4WD for a few months so I have some breathing room if it won't frag on me between now and repair.

 

[Walkercraig01]

I think hubs go out on these rather commonly might start there I think your on the right path but im no way an expert

 

[retiredsparky]

One test for hubs going out is to use a digital thermometer (about $30 at home depot) to check for excessive temp after driving for 30 minutes. As the lube dries out, friction increases, heat results. Compare left to right.

You can also jack up, grab tire top and bottom and attempt to wiggle in and out. should be no slop.