Thunking under heavy load, 1st and 2nd gear

[pred]

What is it?
I can take off without the rumble but its tough,
The more gas in 1st gear the worse the thunking noise.
Feels as though a "U" joint is moving and hitting something but looking under the car I cant find anything loose,
Guibo looks as new, No cracks or even stress marks,
Engine and motor mounts look OK, But cant tell by looks,
This happens in 1st and 2nd and fuel related so it HAS to be drive train somewhere,
Car is a 97, 318ti, asp with 156K miles, Active.
Before I go and start swapping parts, Which I really cant afford as I will also need a clutch real soon,
What do you think the issue is and is there a test I can do to find the issue?
Thank you
Peter

[MINIz guy]

Did you check the driveshaft center bearing? It could be shot and the driveshaft is moving around when under load.

[pred]

Theres a center bearing ?

Guess I gotta go look again

[Strawman]

Could also be the non-replaceable u-joints. Mine were stiff when I bought my car in April 2012, and I had to replace the driveshaft (~$550) with a remanufactured one, not including exchange fee that was refunded when my old driveshaft was received by the vendor. If memory serves, I got it from Turner Motorsports but I could check the receipt tonight if you're interested.

[Lbcnu24]

How many miles are on your car when you Are noticing this noise?

[1996 328ti]

I had a bad u-joint causing the thunk.