Front drive shaft noise/banging

[WolfinJeepsClothing]

I have only put a few hundred miles on my Humvee M998 and on yesterday after making a left turn at a traffic light it started to shake and bang. Sounded like the front drive shaft was pounding on the floor. My first thought was front differential gears or transfer case gears/chain let go, but after getting a lift home from CAA (after 20 miles it got to the point I wasn't going to drive it home) I noticed there is some give in the centre carrier bearing.

Is it posible for this to cause such a catastrophic shake?

At first it calmed down after driving a bit, and it would usually return if turning or accelerating.

Any thought appreciated, and if there are parts locally available. Part #211415x.

I am hoping I don't need a diff. Or t-case!


P.S. it was in H range, I have never put her in locked mode yet, hasn't been slippery enough.


Thanks in advance,

Wolf

[Monk]

The centre bearing is a more common issue

Make sure to chcheck your ujoints as well, while under there

<a data-ipb='nomediaparse' href='http://flashoffroad.com/Maintenance/Dri ... eShaft.htm' class="bbc_url" title="External link">http://flashoffroad.com/Maintenance/Dri ... aft.htm</a>



Hopefully not a stretched transfer case chain, either way , I've never changed a centre bearing, but looks like a gnarly job, to get that bearing off the shaft , hehe

[WolfinJeepsClothing]

Thanks for the link Monk,

It sounds like it is worth pulling off the drive shaft to check it out. My centre bearing isn't visibly damaged like the one in the write up and I lifted a wheel and spun everything to check for obvious binding or roughness. There is a bit of backlash and chain slap when rotating the shaft back and forth which did not appear excessive. Another good thing from the article was a confirmation that you can drive without the front drive shaft in place. If it is something I can't fix in my driveway at least I can get it to a shop.


In my case, I may be able to try the rubber shim trick to see if it helps....


Thanks again

Wolf

[WolfinJeepsClothing]

Here is a dash cam video of the driveline noise.

[Monk]

Lol I keep waiting for this vid, I feel like a chIck waiting for a phone call after a date.. Keep waiting for the phone to ring , in this case waiting for the video to start, heehhe

Then I hit refresh to make sure my computer (aka phones) still working

[WolfinJeepsClothing]

It looks like it didn't load I will try a third time. This was just before I called CAA, I had another 20km to get home and I was afraid to have the driveline grenade on me.

trim.D18150C1-4AB8-4343-9FBD-F092E8D266FF.MOV

 
 
This won't playback on my iPad or iPhone but should play on a PC or Mac. Strange since I uploaded it from my iPad.

[WolfinJeepsClothing]

This is the play I have in the centre carrier bearing, is this normal?


Hopefully this video loads OK

[Monk]

I will have to check the first video on my computer as it does not have sound on my phone for some reason, lol luckily you had a spot to pull over nicely on the road.

As for the bearing, I'll wiggle mine tomorrow...

I'm to understand they move a little (rubber part) as some tuk in inner tube pieces I guess...

Let me check tomorrow as I have never ever touched my bearing, I'm kinda curious now also.

Also just in case don't just focus strictly on the bearing but also look over front-end stuff,as it could be a whole bunch of things

[ddgermann]

This does not sound like your centre bearing....as bit of play against the rubber mounting is normal. Mine is the same. Something has come loose for sure. Very metallic clanging. Sounds like an internal noise... in a case or gearbox. Did you pull any plugs and look for chunks and filings? Transfer case...hubs...diffs... tranny.
If you cant not see any obvious problem in the driveline....I would get this truck into Roys shop asap. Before you grenade something.
 
Catch it before it becomes... big $$$
 
Hope you find and sort it with minimal problem. Very curious to hear what it is. Good videos BTW. Very clear sound.
 
Derek

[Roy]

Are any of the u joints loose---push shaft up and down and 90' to joints
Wait, I think this may be right...
try and pry your calipers up and down...do they move--the main bracket??
if so, your retaining bolts are chewing the cv shaft bolts,
or, the cv shaft bolt is loose and is eating the alum caliper bracket.
Let me know.
 
Other than this,
check cv shaft for clicking--blown joint, 
and check this last...
remove the hub side cover and check for gear teeth issues.. not likely tho, never seen it.