rear end is noisy from 25mph to about 45mph is rear end bad then above that its fine

you have to check these for the suspension: have you checked your suspension if any of the struts or shocks are loose? did you have any adjustments before because im pretty sure if you had any changes, you might have not tightened it well or it was too tight... and if you had uite a lot of years, it's pretty normal becuse the suspension is worn out... for the rotors: either the rotors are loose or drum brakes are worn out and that sound might be the brake pads scratching metal...sometimes the faster you go the louder it sounds... bearings: the bearings might be loose or cracked, remove the wheels and the whole drum and see if the connector bearing is still in shape...

The rear end has disc brakes and they are ok . The suspension is OK all is thight.Above 45mph the sound goes away. I pulled the fill plug and I could not reach the gear oil not until I strained down further and then there is anti slosh plate so I could not see how much there was in the monster. Thank you for your response anyway Mac