Transfer case/driveshaft vibration

[schulte]

My dad's got an '04 2500HD 6.0L gasser with the manual floor shifter. About 55,000mi on it. Some towing, nothing more than 8,000lbs here and there.

Got a BAD vibration between 65-75mph, especially bad when accelerating. Sounds like maybe pump rub in the transfer case has let all the oil out, or maybe a bad u-joint.

Weird part is, it's supposedly been like this for about 5,000mi. 4x4 still works, shifts easily into 4x4, etc.

Got two videos... first, the vibration under acceleration (60-75mph); second, the shifter movement under acceleration (all speeds).

Any ideas?

[Noreaster]

my shifter does the same thing while accelerating

[schulte]

Does this seem like it could be caused by no oil due to pump rub?

[schulte]

Just replaced the U-Joints today; no change.

Also notice t-case almost empty; about 4oz of BLACK fluid came out. Re-filled it with Transynd (didn't have any Dex-III on hand).

No change.

Also notice the driveshaft has a few areas that're dented. No dents deeper than 1/8", but they're definitely there. Not sure if this could cause/contribute to it.


Anyone wanna wager on internal to the transfer case vs. output shaft bearing?

[LBZ_Duramax]

The fluid evaporates and was likely overdue for an oil change. BTW my dads 1500 with the floor shifter does the same thing.

[07dirty]

i just put 5w30 mobile 1 synthetic in my case and now i have a bad vibration too. but im thinkin it has to do with the pump not being able to pump it has quickly plus my brand new output shaft seal is leaking also. so im gonna put atf back in mine and see if that helps. i think your is the pump hub tho, my transfercase doesnt fall under the catagory of pump hub, but i believe yours does since its a 04

[dmaxfireman]

dump the atf and fill the t-case with 5w30. if there is a chance aat saving it that will help.

[duramaxdiesel]

Dents are never good no matter how big when it comes to a driveshaft. Remember, that thing is spinning pretty fast. Maybe it's out of balance now?

Nick

[DuramaxSMOKE11]

juat went through this with a workd truck. the tailshaft bushings were shot in the t-case and the driveshaft was bent

[07dirty]

i still have a vibration aound 64-69mph. i put atf back in in it and that seemed to help alot. it only vibrates under a load and in top gear. it had a bad carrier bearing, so i installed a new carrier bearing. that seemed to help. but its still their and bugs the shit out of me, it vibrates on cuise control also when set at like 64-69mph range.

[schulte]

This ended up being a dented driveshaft. The dents were very very minor, almost unnoticeable. I brought the shaft to a driveshaft shop and they checked it for balance and found the dents.

New driveshaft, problem solved (for now, until the transfer case lets go because it was run out of oil).

[Jetty LBZ]

my dads transfer case started poping and when he got on it the trans didnt want to shift. we took it apart and the gears were wore out and we had to get it rebuilt but his truck has 300k on it and thats the only problem its had thus far.

[07dirty]

i just bought a tail shaft bushing and bearing. maybe that will take care of the problem

[07dirty]

tail shaft bushing and bearing was my problem... btw i had a broken pump hub clip too.

[mtl_dmax]

I got my front end totally rebuilt and now I've got a vibration at highway speed primarily under load. All the U-joints felt fine and the only play I saw was on the tailshaft bearing as well as the front output shaft bearing. I'll need to pull my transfer case to fix the pump rub anyway so I may as well get the full rebuild kit with bearings and seals to do it all at once. Truck drives great except that vibration so it's quite annoying to say the least.