H3 Humming noise, front CV driveshaft bad, and play in front output shaft of TC..

[Guerrero]

Hello All,

I'm new writing but not reading, this forum is awesome!

Ok, i tell my story with this problem, I'm a happy owner of a 2006 Hummer H3 here in Spain, recently I change the front differential crossmember bushing with the Outfitter Design Kit (only replace the bushing in the crossmenber, the bracket bushing will be replace in the near future) when I replace the bushing, I put off the crosmember and let the diff support with the front drive shaft still atached, next I reinstall the crosmember with the new bushing with no problem. Next i take the Hummer for a test run, and a noise appeared suddenly hitting 30 mph, a loud humming noise that more fast you go more noise you hear, but sometimes quieter/sometimes louder (depends of the speed) all of that noise with a vibration feel in throttle pedal.

Today I put the car in 4HI LOCK, and put off the Front Driveshaft, again make a test run and the Hummer goes very nice, smoother ride and no noise (no tire noise then), only a bit of humming when hitting 30 mph but nothing crazy like before.

-FRONT DRIVESHAFT: I check the Front Driveshaft and a CLICK noise is heard when you rotate the shaft over the CV (but the strange thing is that the click is notice in the middle of the shaft and not in the CV).

-TRANSFER CASE: When i put off the Front driveshaft, I try to move the Yoke in the Front of the Transfer Case (Yoke that is in the front output shaft in the transfer case) and has movement in it, in/out movement (like 0'3 centimeters), and has a bit of movement in the up /down and side to side too, but it is much less movement that the In/out movement. (I dont refer to rotate movement that i know that is normal).


I think that my front driveshaft needs a new CV, but the movement in the yoke of the transfer case is normal? I don't think so..
I try to tigh the nut in the Yoke and It is very tight, so I dont know.. (The yoke moves with the shaft when you make movements in it)

Hope someone can help me..

Again Thanks very much for that great Forum, I want to make a formal presentation with Pics of my ride.

Thanks, Guerrero

 

[Bigunit]

Welcome.

 

[alrock]

Not sure, I really haven't played with the transfer case mechanicals.

 

[Guerrero]

Thanks for responds,

I think that in another thread 06 H3 that I think is Chris, had this happen in his truck,
I wait impatient for another responds!

Thanks and sorry for my maybe wrong english

 

[4speedfunk]

Guerrero... The Outfitter Design kit uses a much harder bushing material, and you can expect more road noise & vibrations to be transmitted to the cabin. That's perfectly normal when you upgrade from rubber to urethane bushings on any vehicle. I also think this is why GM used such soft rubber bushing to begin with. That being said...the harder bushing material may be un-masking some issues that were hidden by the soft rubber bushing.

The front driveshaft CV is a troublesome part and when it goes bad, it can cause vibes, humming, and metallic "pinging". And yes, the bad CV can sound like its coming from the middle of the shaft. Somehow the hollow metal tubing seems to amplify the sound of the worn CV, and this seems most noticeable in low-range, under 10 mph. Check the rubber boot (inside the cup on the end of the shaft) for rips and see if you can "shake" the CV...it should not flop around when you shake the driveshaft. The CV itself should have approx 1-1/2" of plunge, and that's normal....but it should not be excessively loose. The rubber boot should be soft and pliable. I suspect the "click" you hear may stem from dry balls inside the CV. (okay...I know that will get some comments. Be nice).

The output shaft of the T-case does have some end play. But the up-down and side-to-side movement is a problem. You may have a worn output bushing (or bearing) inside the t-case. I've not had one apart yet but, I think this is a fairly common problem. Have that checked out, as it will certainly cause more trouble if it is not fixed. T-case work is fairly cheap if you can catch stuff like this before it explodes and ruins the cases.

 

[Guerrero]

Hello again, thanks very much for great respond 4speedfunk,

The CV in the driveshaft was bad according to a tranny shop that repaired it two days ago, reinstall in the Hummer and a Clunking noise that had before now dissapears, but the annoying humming noise is still there.
I take the car to a friend's garage and put in the elevator, then start the car and put it at 30 mph, We checked under the Hummer and nothing about noise, only smooth and fine transmission and component rotating.

I have a set of BF Goodrich All Terrain T/A LT 285/75-R16 till 2009 and put 40000 miles on them, we think that is tire noise related, and In this week I'll try to replace them with a new set.

Thanks Again, and hope that the humming issue is from the tires!

Guerrero