Noise from rear diff?

I get this clunking/thudding shuddering sound from my rear end every now and again when i turn corners.(mainly left handers, sounds like the whole rearend shifts underneath the vehicle) I have the factory posi or whatever they consider it. I changed fluid and put in the synthetic that was recommended, i found something on the net about metal spacers or something that go bad with these rear ends?? Anyone had this problem or know how to fix it? I just dont want to have it lock up or shell out going down the road.

If i have to replace the posi, anyone have a recommendation on a good brand besides the stock one? would a detroit locker allow enough wheel spin during corners for road use or would it chirp tires?
by the way this is on a 04 tahoe 5.3l 4x4 if that matters

no idea what it is but that g80 limited slip posi is common to go out on these 10 bolts.

stop and park it now! save yourself some money. Just got mine back from the shop and 2 grand. same symptoms as yours

what the hell did they put in it was it made of gold

lol i whish. heres the list: ring and pinion and all bearings, axle seals, had to clean all the metal fragments out of the diff and tubes, ring and pinion gear set, rear end carrier, 3 qts of gear oil, 1 qt posi track fluid, axle seals, plus shop supplies and labor at a discount.

have the u-joints been inspected lately?

Mine did what you explained but I was 20 miles from home so I limped it home and by the time I got home I tore my trans up cause the rear end locked up once and I lost second gear. That ended up makin me drive from NC to WV for a 700 dollar 4L60 then a 1100 bill for my new rear end. My tahoe has the 5.3 with 342 gear so I upgraded to a AAM 4:10 gear (AAM is who GM gets their gears from so either give chevy 600+ for the same brand you can get for under 200 if you hunt around). I went ahead and bought a Detroit trutrack which works great. It's not a full locker so you don't have to worry about anything.

I got the gear, trutrack installed. With all hardware and rebuild kit... I mean everything, complete overhaul for a little under 1100 from a well known shop called Galloways in Richfield, NC.

so is our g80 the same as the eaton g80? what is a good upgrade from this rear end? what i have heard about the eaton g80 sounded pretty good cause it splits torque and can lock up

get a detroit trutrack

i hate it when rearends make noise

Excuse my ignorance but, is the G80 an option code for the posi or is that the model of the rear-end?

Does anyone have a breakdown of what the option codes relate to?

Thanks

Disregard my previous entry, newbie mistake.

Good site for RPO codes: http://www.gm-trucks.com/rpo-code-lookup/

Not that this isn't a good site keep up the good work.