4x4 Noise/Problem

[IllogicTC]

I usually always leave my selector in 2HI, mainly because most of the year I don't need any 4x4 functionality.

A week ago or so, we had heavy snow which required me to use 4HI. It was acting up a little bit, not sure if it's from disuse or another issue, but the main problem I am worrying about now is in 2HI.

As far as I can tell, the disconnect SEEMS to be working, but maybe not completely. 4HI definitely feels like 4HI, and 2HI definitely feels like 2HI.

Symptoms:
--IN 2HI--

*A rattling/clanking sound when moving forward. It becomes more rapid, obviously, as wheel speed increases. It starts at maybe 3MPH, really low.
*Bumps do not seem to affect the noise, but I can't really tell. There's only two kinds of road here, nice and smooth or way too bumpy and full of holes to take at any appreciable speed.
*As far as I can hear, the noise does not show up when moving in reverse, or is at least very minimal.
*Sometimes, rather than the rattle described above, it's like a metallic pop pop pop, seems to be about one pop per tire revolution, and is not very loud at low speeds and not deafening at 40MPH or so, where the sound seems to peak out.
*One time only, but had some hop on a sharp turn when turning. Not sure if related.

--IN A4WD--
*At highway speed, it makes a similar noise, maybe a little louder, but then some sort of metal grinding/rubbing noise shows up, and stays consistent, until 2HI is selected.
*When switching into A4WD at no/low speed, I do hear the motor activating, and can feel the slight difference it makes.
*When switching into A4WD at 45MPH (tested at this speed, at least) there is a very noticeable grab (like the whole vehicle bogs down for maybe 1/4-1/2 second) when the front axle engages.
*Switching out of A4WD to 2HI reverts to the above symptoms, sometimes a little worse, sometimes a little better.

--IN 4HI--
I haven't tested 4HI much, mainly for fear of making something worse than it already may be.

*About the same as A4WD (only tested at low speed), but any appreciable throttle application which sends a good amount of torque to the wheels, there is a loud BAM BAM BAM noise.



Before I read up on how the front axle works on the TB, I assumed it was a problem with the hub (my old vehicle had automatic hubs, the old fashioned kind where the wheel clicks to the axle, instead of always being engaged with the axle), so I tried shifting to 2HI while going in reverse, and other silly things.

Sudden accelerations and decelerations do not seem to have any effect on the noise, no matter which mode is selected.

This happened to me once before, but showed up to a very minor extent, and it turns out one of my tires was at 30PSI while the other was at maybe 24, and evening the pressure out made it go away?

I am absolutely stumped. I've been reading up a lot, and I'm thinking front axle engagement, then I'm thinking bearings, then I'm thinking this and that or the other thing.

I would love to be able to just throw piles of money at it right now, but my financial stability is extremely limited. I know there is no guarantee of a diagnosis just listing my symptoms on the Internet, but it's really the first place to start before I go grabbing parts and trying DIY or (Lord Forbid) trying to save up enough for a dealership visit. If anyone lives near the Ohio/West Virginia border would like to drop by and see for themselves, or have me bring it to them (if it's really necessary), I might be able to accommodate for the sake of trying to keep costs down.

[fishsticks]

Check the fluid level in your front diff. I have a funny feeling you're in for some bad news.

[IllogicTC]

Likely with my luck. 97k miles, couldn't get a hold of the maintenance record when I purchased it. There's a few records on Carfax, but I ain't payin'

[IllogicTC]

Then again, why would it only show up moving forward if it's the diff? I'm going to check it anyway, because why not, but the diff moves full time, wouldn't it be expected the noise would be happening going both ways?

[IllogicTC]

Ran through some of the flowchart. Couldn't do all of it because I couldn't find any jackstands to safely bring the whole front end up, and forgot to check if the prop shaft was rotating, but:

In 2Hi, the prop shaft freely rotates.
In 4Hi, the prop shaft is pretty solid, maybe 1 degree of play.

After jacking up the passenger side:

In 2Hi, the wheel moves with no issue, but seems to take a little effort. I'm not sure if this is normal (so used to hub-style disconnect)
In 4Hi and in A4WD, it moves just about the same as above but I hear a clack clack clacking noise. I'm thinking this might be the same noise I've been hearing, but doesn't explain why I hear the noise in the original post while in 2Hi (or maybe it does?).

I already know that's a problem, because that thing should be solid. Any ideas on how to whittle it down further? Unless I can find jackstands, all I currently have is the OEM bottle jack and there's no way I am getting the whole front end up, or leaning a bit under to see the prop shaft (thanks, whoever put the runner boards on).

[navigator]

A. H. if you are doing any work yourself, you need jack stands.
You'll need jack stands to diagnose the issue and likely to resolve the issue.
You might also update your location in your profile. It might be another member is close by you and will help you troubleshoot.

[Trail X]

Check for play where the CV shaft enters the disconnect on the passenger side. Push up and side to side with all your effort on the tripod cup and see if it moves more than 1/32".

To me, it sounds like you could have a malfunctioning disconnect. If there is significant wear in the front disco, it can make noise even when in 2WD. That - or you have a wheel bearing that's also going out.

See if you can locate that clacking noise, and as Chris said, if you're doing any work on your truck, you should have jack stands.

[plaen]

To me, it sounds like you could have a malfunctioning disconnect. If there is significant wear in the front disco, it can make noise even when in 2WD. That - or you have a wheel bearing that's also going out.

See if you can locate that clacking noise, and as Chris said, if you're doing any work on your truck, you should have jack stands.

x2 for both of those statements, sounds like the fork may be just slightly engaging in the disconnect, enough to make the collar click as the gear rotates. Just replaced a hub/bearing for a deep loud humming from the left. At the same time, 4x4 didn't work and was clicking exactly as you describe, pulled the disconnect, found a broken fork, replaced that, and the clicking stopped and 4hi resumed working

Jack Stands are a requirement for working under a raised vehicle, I've had a few fall off a jack before I started work luckily, and now I refuse to touch anything without having at least 2 jack stands supporting it.

[IllogicTC]

Oh trust me, that's why I didn't get under it to see if the prop shaft was turning. Wouldn't have had to even get under really, but have my face toward the ground near it lol. I thought we had some around here, my roommate's dad was mechanic, but it's all in disarray in the storage room and there's lot of incomplete sets of things down there.

I know while in 4HI it definitely felt like it was in 4HI (3HI with the broken fork?) it got me through a patch of snow pretty well, so that's a likely suspect for me. I'm scrawny so I could maybe get under there without jacking to check the CV since it's not too far back.

Also, location information updated. At this rate, I'm willing to try raising some money for gas and beer (still got a little of my refund left) if someone could help, lol.

[Trail X]

No such thing as 3HI... unless your diff is seriously jacked up.