Yes, I am wrong in the video. It is speed dependent, NOT by rpm.

Only audible when accelerating in a forward gear, not in neutral.

Front shaft? I have a receipt of it being lubed a few years back. That is one other thing I have not checked yet either. But, they do have zerk fittings on them, just one I believe.

 

You can rule out the front shaft very easily if you have a Differential Lock on your transfer case. Here's a picture of what mine looked like:



This is looking at the transfer case from the front of the car, you can see where the front drive shaft connects to the transfer case on the left. The nut on the bottom of this shaft rotates clockwise (easily with a wrench). Or better yet, it may be connected to a cable that runs to you transfer case shifter inside so you'd see the normal high and low, plus lock and unlock. If you have either way to lock the transfer differential then you can remove the front drive shaft and the truck will still drive just with the rear. If you still have the noise without the front shaft we can go from there. But either way plan on replacing that non grazeable driveshaft before it shatters on the highway and destroys your transmission!

 

Transmission is sealed. All that means is
they don't make it easy to unseal it.
There is a plug on the transmission when you get under there and get it out.

Secret to filling it is ..
Little transfer pump

Run the engine and go to N.
Put your ebrake on
chock the wheels.

Then go under there and fill it up.

I think that noise is a differential or your transfer case.

but in any event - you need to check // change the transmission fluid no matter what if you are keeping the beast.

 

Thanks guys, I have to take off to Florida for a couple days, will get back to it on the weekend with a squirt in the shaft zerks and a closer look at the transfer case.

Drove it another 20 miles last night and it ran perfect minus the whining

 

Hope your issue isn't as bad as mine. My issue was the front differential was shredding itself as evidenced by the metal flakes in my fluid. Ugh.

 

I bit the bullet and had a new tranny and transfer case installed.

Runs like new, and worth every penny. I had to give up the S500 today and back to the Disco, that was a bit of a change

Case closed.