[V8] clunking 90 v8

[chris brown]

 I have began to notice some clunking under the car when i accelerate. It feels like its coming from approx  under the drivers seat. I get this noise more when i accelerate going up a hill and i have a load on the engine. If i let off he gas, the clunk goes away. 
I had a similar issue with my 87 quattro and it turned out to be a loose exhaust being slapped by the drive shaft. As a matter of fact this noise sounds just like that. I put the car on ramps and checked the exhaust and it's tight and sturdy.  Could it be my front drivers side axle?  Its really bothering me. Ive had the car on the road 6 months and this sound has just began.  thanks