Transmission noise
 

2004 Edge 3.0 162K 2WD.
Got a new issue with the old truck which has given us good service for a while now. I am not primary driver of the truck so I don't how long this has been going on but drove it the other day and noticed a weird whining, whirring sound somewhere in power train. Transmission or rear axle most likely. Engine is quite and there is no noise sitting still. Shifting is normal in city speeds, I did not take it on the highway.
Changed tranny fluid last year and at the time all looked good, for example pan was fairly clean, not a lot of smudge you usually see.

I rode in back of truck trying to define source of the noise but was not able to do so. Sound was loudest coming up between cab and bed.

Anyone else had same kind noises?

If it comes down to tranny replacement, how much trouble is it to pull tranny leaving engine in place? I have some experience pulling engines and trannies and have done it both ways. Never on garage floor though haha.

Thank you.

I would block the tires and then drop the drive shaft, just 4 bolts, put a pan under tail shaft, fluid will leak out
Check u-joints and lube slip joint

Put it back in then jack up the rear wheels
Start engine and put trans in gear
You should be able to hear where noise is coming from now

Thanks RonD, will do. Probably will be few days before i can get to it, hope it keeps going meanwhile.

UPDATE:

Lifted rear of truck and ran it up to 30 mph on stands. Best we ( a novice and myself) could determine that source of the howling noise was around the axle.
There was some oily mist on the exterior of the pumpkin but nothing indicating major leak causing it to run dry.
Changed rear axle oil while back and saw nothing alarming. Added proper amount of friction modifier to new oil.
I swapped the original axle to this one from junkyard because i wanted limited slip axle and until now the junkyard axle has performed well.

Oh and antilock warning light came on also during the test.

If the issue is somewhere in the differential I may just install the original axle back into the truck.

Any thoughts?

That's probably because the front wheels and rear wheels were turning at different speeds.

scheduling axle repair/replacement for early next week. I am thinking there is little I can do if something is wrong with pumpkin internals. I do have new axle bearings and seals ready to go if that is the cause of the noise.
Otherwise i am going to end up re-installing the original axle which I still have. Truck is daily driver for family member with limited means so I gotta try to get it done in a day.

Any thoughts?

Thank you.

Re-installed original axle and noise is gone! Good thing I tend to hang on to things so I still had it!! Big job for me and novice helper but i am glad the trouble shooting pointed us in the right direction.
The removed LS axle is hard turn and grumbles turning it with cheater bar. Maybe someday I will open it up for investigating possible causes of failure.