Motorcycle Repair: whirring noise, harley electraglide, harley bike

Question
Hi,
I paid for a full service on my 1340 Harley electraglide sport evo 93 Euro model( mileage is  37,000) after it had been standing still for about  six months ,over our drawn out UK winter. I am no mechanic by along shot and have to rely on a bike shop to do the servicing. Unfortunately halfway into a 250 mile ride south  at Easter the bike began to make a horrid  loud whirling noise above the normal rumble of the engine. This noise has persisted ever since and does not change  in volume or sound wether the bike was idling with clutch disengaged or the bike wass on the move. It  sounds much like a jap two stoke "ying ying" noise that runs above and  in time with the engine tick over sound.YUK! I took the bike to another  Harley mechanic who is anticipating its  to do with transmission and  bearings. He discovered the  primary chain and rear belt had been considerably over tightened and there was  was no oil in the gear box. He said the gear  box was not leaking and he felt the service I had paid for had not been done at all. He said the opening nut to the gear box oil chamber was actually seized on and obviously had not been undone for a very long period of time.I am gutted to think I paid so much money for a full service and this particular Harley bike shop had caused serious damage to my bike .What I would like to ask you is if you could please give a second opinion as to what may be the likely cause for such a sound to occur. I have been advised by  the other mechanic to only ride the bike no further than 100 miles at one time and avoid letting the bike get  to heated. I am reluctant to ride the bike at all in its current state for fear  of causing further damage or it siezing , although this mechanics has placed a silicone  additive to the oil he replensihed to the gear box so he said I could have light use of the bike  and to bring it back in Winter to be repaired when he has more time to do so. So far I have been offered two theories. My friend suggested  getting a second gear  box refurbished and  replacing it so save labor cost .My problem is i do not want to go ahead  and get wrong parts  to repair the bike. Its been suggested its the gear box/ transmission that at fault but another friend of mine also a Harley owner bike builder reckons it cant be the gear box because the noise is still the same with clutch disengaged/ neutral so it must be an engine part that is in motion when only the bike is left in neutral and the engine is just ticking over. Any ideas? Many thanks. Samantha  

Answer
If you rode your bike with no oil inthe tranny then I would start looking there. You probably hve a bearing going out. I would ride the bike at all. If the bearing goes out you might damage some gears or at worse lock up the trans and crack the trans case
Good luck and happy riding
Mike