You may be able to find my postings in the archive but if not here's a summary of what was tried by 2 different garages ( and the problem still persisted!):

New Centre bearing (fitted with and without pre-load)

New Guibo

Old guibo refitted as (new non-BMW part that was fitted felt 'softer' than the original and the original was a little worn but didn't look that bad)

New U-joint

Propshaft balanced

Propshaft from different car tried

Driveshafts from different car tried

New Diff mounting bush

New Transmission mounts

New subframe bushes

Position of the centre bearing raised and lowered.

Each time the car just did exactly the same thing!....Pull away (not even that fast) and "Bang, Bang, Bang" felt like the damn thing was gonna come through the floor yet once at normal speeds...no problem!

Eventually, I got so sick of it I took it to a BMW main dealer.They told me that although they appreciated that all those things had been done before they wouldn't start working on the car unless I agreed to let them change the Centre bearing and guibo as a starting point. I agreed. They ordered in the parts but then phoned me the next day to say that the work would be delayed a day as the centre bearing had come without a 'housing'. I was surprised by this as the two previous centre bearings didn't have a 'housing'.It was also interesting because one of the previous garages had been told by another main-dealer's parts dept that the centre bearings on all E28's were the same!

Anyway, the parts arrived the following day and they fixed the car within 1.5 hours! I haven't been under the car yet to see if things look different. But it's a thought. And it shows that sometimes it pays to 'bite the bullet' and give it to the main-dealers (apparently there's also some tool they have for checking alignments?...maybe someone here can shed more light on that?)

When I get a chance I'll take a look under the car and see if the parts look different.

Meantime best of luck and don't despair...I got so sick of it it got to the point where I just felt like throwing the car away!

Derin

Pulled it again today...new guibo and center bearing...u-joints have no slop, nor are they tight. Lined up the arrows, paint spots, and center punch marks (had all three)...pre-loaded the new bearing (twice)...still has audible rumble under acceleration from between the seats...and I do mean audible! I also replaced diff mount (badly in need of replacement, masked the driveshaft noise)...tranny mounts appear new, as well. She's been mine for three weeks and I'm already wishing I hadn't sold the 2002! Her rear end is sagging...she needs rear springs and shocks. Could this be a contributor to the problem. I'm needing some serious help, here. TIA. Mike