unknown whinning noise

Looking for any information and advice on my 1998 dodge ram 1500 2wd. My dodge ram has 112,000 miles and has recently developed a whinning noise which I thought was my rear differential going bad. I jacked the rear wheels off the ground and crawled underneath as the rear wheels were engaged and turning. The whining noise is coming from the drive shaft (front universal area). Before lifting the rear end off the ground, I had a mechanic listen to the noise and he said no doubt about , a bearing is bad and at the time it sounded as the rear differential was the culprit for the noise....however when under the truck the noise is 100 percent coming from the drive shaft front universal area. I took it to a local transmission shop and he said the overdrive bearing was going bad. He installed a new one ( showed me old one and it definitely had some wear) however this did not eliminate the noise. The transmission shop said the noise sounds like its coming from the drive shaft...which I already mentioned. The transmission shop did not want me to pay them for it didn't help the situation. I asked if the transmission is going bad, said they used a stethoscope from the rear end to the motor and only noise is the driveshaft. Asked if it could be universal? Said they never heard one sound like that and didn't think that was problem. They said drive it, the transmission is fine.

Noise is a whinning noise, starts at about 5 to 10 mph and gets louder as u go down the road with increased speed. If u get going to fast, noise seems to go away bit I think its do to increased road noise. It does it in reverse, whether your giving it gas or not. If trucks moving it makes the noise. There is no vibration, no clunking....SO any ideas? I might change universals but hate to waist money if that's not the issue.

Thanks everyone.

u joints are cheap, check for play in the driveshaft yourself. if nothing else, you won't be wasting much money replacing them.

Sent from my XT1575 using Tapatalk

Will replace Universal's tomorrow and let u know if that's the problem. There is no leaking or slop in the drive shaft. Keep u posted and thanks.

Changing out universals didn't solve the problem. Disassembled the rear end, now just debating on whether I should rebuild it or buy a used rear end. Found a few for 200 or less that are already off the trucks and ready to just bolt on. Few questions if anyone has the answers. What is the newest year rear end I can use on my 1998 dodge ram 1500 2wd? Can I use the rear end out of a 4wd truck on my 2wd. Appreciate any advice. Thanks