My front driveshaft has a little bit of rotational play in it, maybe about 25 degrees (I suppose that would be around 1/2 inch). Everyone I've talked to about it says it's normal (including 3 shops). But I don't have that clunking noise your talking about, and last month when I was in my front diff I didn't find any looseness in the gears. I've got the 3.55s as well.
Now I did have that routine clunk up to last year when I had all the original U-joints replaced. I've got more noise now, but that will be taken care of soon when I get some new CV axles and wheel hubs to replace the current ones with 193,500+ miles on them.

 

[QUOTE=Caseys-dodge;2607833]My front driveshaft has a little bit of rotational play in it, maybe about 25 degrees (I suppose that would be around 1/2 inch). Everyone I've talked to about it says it's normal (including 3 shops).

That is good to here. They closed up the differential and put new gear oil, drove it today and have not heard the noise. Maybe the oil just needed to be changed. I have never done it before.

 

You are aware that the differentials call for a fluid change every 30,000 miles (15k with severe use) aren't you? And you were wondering why it made noise???

I got a news flash for ya', ANY moving part will have problems with premature wear when you don't lubricate the thing!!! I'm sure wherever the hell you read that was from another genius who doesn't know the definition of the word MAINTENANCE... Yeah these trucks have known issues, but the differentials are not one of them. Now the LSDs, that's another story...



Oh well, hope the fluid change is all that was needed, you might luck out...

 

Sorry about not knowing that. Truck has been out of warranty for a long time and I have never done that myself before. Like I said I am not a mechanic but I can do the simple stuff but now I see how easy it is to do the differential fluid. Thanks for the lashing!!!!

 

LOL, I wasn't lashing. But it kinda gets old reading post after post from guys who have failing components and blame the truck when they've not done the required maintenance on the vehicle. Not you, just a cumulative effect.

You want that thing to remain trouble free and not cost you big bucks over the long haul, READ the owners manual and do the required maintenance at the designated times/mileage that the engineers who designed the thing spec. They know a LOT more about that vehicle than you or I do...