Random vibation on long distance

[flatout man]

2002 denali AWD, if we drive for half hour or more it suddenly feels like you are driving on the warning bumps before a stop sign. We pull over then start again. In ten minutes it starts again. Any short distance its fine. Did the wheel bearings, 2 new rear tires, balanced all tires. Not sure what to do next. Don't want to take to dealer yet, cost a bit to much. Any suggestions???????

 

[Sasquatch]

That`s an odd sounding problem because of how long it takes to show up and then goes away after stopping.

From being a member here i`ve learned that trucks with AWD tend to have front differential problems. I`m not sure if that could be your problem but i`d check it out. Drain it and see how much metal is on the drain plug magnet.

 

[flatout man]

I did drain and noticed a bit on the magnet. Another thing I notice is how close the exhaust is to front driveshaft. My next step is perhaps the u-joints. If the longer you drive the shaft will be hotter and cause u-joint issue/vibration.....worth a shot I guess.

 

[GangstaCowboy]

Does it go away if you hit the gas or brakes?

 

[flatout man]

no it doesn't. Have to pull over and come to a complete stop.

 

[flatout man]

So went camping last week and had to pull over a bunch of times. 1st time took an hour for vibration to start. Put in neutral and still did it. I am baffled. I love my Denali but don't want to randomly put parts in it. Seems like its more on passenger side. Also just before it happens feels like brakes are on a bit, that feeling as if there is resistance. Tried to floor it and the vibration had longer intervals too. Tire? axle shaft?

 

[flatout man]

found the problem. the front diff outer left bearing has went for a crap. is fine until it heats up. Getting front diff changed out Tuesday. The fluid was almost boiling when it was on the hoist at the shop.

 

[Goodinblack]

Wow. Almost boiling

 

[GeneralNoobzor]

found the problem. the front diff outer left bearing has went for a crap. is fine until it heats up. Getting front diff changed out Tuesday. The fluid was almost boiling when it was on the hoist at the shop.

How much to get it replaced/rebuilt?

 

[flatout man]

gonna be around $1000CAD. Also go extended warranty on used diff as well as doing the u-joints on front drive shaft.