Any help would be greatly appreciated.

I noticed my truck making a whirring noise this week after my brand new wife got back from her 2nd 1000 mile road trip in two weeks moving some stuff(no trailer, just stuff in the bed and not exceptionally heavy). I haven't had time to get it checked out because I got married yesterday and had to drive another 400 miles. It has gotten a little worse. I jacked it up to try to find where it is coming from. I think it is the transmission.

When I put it in drive the sound immediately starts out as a lower tone and as I speed up the "whir" becomes more high pitched. It is an automatic and the tone continues to become more high pitched regardless of gear shifting. When I jacked up the rear end the same applies. I put it in neutral and the wheels slow down and the whir gets lower but the transmission continues to turn the wheels. So I put it in park and the wheels continue to turn slowly and the noise continues along with an additional noise. I put my foot on the brake and the wheels stop and the noise stops and the wheels do not try to start turning again.

Am I in trouble?

 

Sounds like a bearing is going out....

 

A bearing in the rear end or the transmission. Honestly the sound seems to be coming more from the rear end.

 

To me it sounds like the ring and pinion gear. Try changing the fluid in the rear and the tranny and see if that helps.

 

I had the oil in the rear end changed about a month ago because the pinion seal had gone bad. There is still oil in there. It does seem gritty, though. Since it is fresh I wouldnt think it should have any grit. The trans fluid level was good and it didn't smell burnt or anything. Maybe they did something bad when they changed the oil back there.

 

I would have the rear check then.

 

See,... it's all down hill once you get married.

 

My thoughts exactly! Just kiddin' good luck with your new marriage. How many miles are on the truck? Does the noise get worse under light acceleration, does it go away if you're coasting? Could be a bad bearing, but I had a 99 Trans Am that started making noise like that, and turns out that I ripped 3 teeth off of the ring gear, and had to replace the ring and pinion. Take it to a good mechanic and have it checked out, there are a few different things that can cause the rearend to get noisy. Could be the limited slip diff. too, they can go.