your h6 has a timing chain
No, it has 2 timing chains.....
timing belt.
The 2007 Subaru Tribeca does have dual timing chains.
Yes all H6 Subaru Engines have timing chains
the 3.0 h6 has a chain,it doest need changing
On my 2001 Subaru Outback Wagon H6-3.0, it's on the driver side(L/H), in front of the wheel well, hidden behind the fog light...
Where is the the vent tube for the transmission located on a 2001 Subaru forester
Where is the bank2 sensor 1 located on a 2001 subaru outback 3.0
By drive belt; I assume you mean a timing belt. On a 3.0 H-6, there is a timing chain in place of the belt (Very durable). It is housed behind cast aluminum timing chain covers on the front of the engine. On an engine with a timing belt, I would do the change myself; but I recommend that a timing chain be replaced by a Subaru dealer simply for the fact that the tension, alignment, and timing can be hard to set yourself with a chain.
As per the Subaru Legacy Service Manual: 5.5 Liters, 5.8 US qt or 4.8 Imp qt...
Assuming that you have the H6, because the 4 has vee belts. Never done one on Subaru but there is a cover called the "collector cover" you have to remove to gain access. Should be just a couple of bolts. From there you locate the belt tensioner, use a wrench pulling clockwise to relieve tension and the belt slips right off. Back on is reverse order. It is the same for any car that has a serpentine belt. I see the owner's manual recommends this be done by the dealer. Best of luck!