Horrible Noise!!!

Help please - towed my boat this weekend with the 90N/A that i have spent the winter getting on the road - all going well untill coasting to a junction on return journey - horrible noises from somewhere on drive train at front. When i pulled away noise stopped when speed above about 5mph. This happened several times on last 5 miles of journey. Once trailer removed, problem seems to disappear. Nothing obvious with front prop externally - any ideas please guys? thanks steve

What sort of noise was it?

Hi Disco - it sounded like something metallic catching at about wheel speed. No obvious vibration or feeling thro the steering. Ive been racking my brains and i can remember when i replaced the swivel bearings that the brass bush that the drive shaft runs in in the back of the hub was a bit worn - do you think it could be that? I drove her again last nite without the trailer and seems ok! thanks
steve

If it only happens with the boat, then the only sort of change is that the rear of the landy is loaded, rear end down, front end up, so the front of the front prop drops a little, could be the UJ's are a bit worn, or need a good greasing.