Remove the inspection plate.

http://www.eastcoastrover.com/Parts.html

Look at the pick, this is what you will see with the inspection plate removed.

 

Or this...

 

I can't see anything visually wrong with that one... Is that the point?

 

it sounds like somthing might have come apart in the front diff to me

 

If you have power in reverse than the t-case is fine, it's using the same input from the transmission as if you're going forward. The t-case has no reverse or forward gears, it just takes the output from the transmission output shaft.

Something likely bound up with the t-case or the diff when this happened and you snapped one of the idler shafts in the transmission. You have a front and rear planetary gear set in an auto transmission, sounds like the rear is fine, and it sounds like you have adequate transmission internal pressure.

I know you pulled the t-case cover, have you drained the trans fluid? It might be time to do that and check for parts attached to the magnet. My hunch is you were sending power to the rear wheels and the front was bound, when the transmission broke lose you had this movement in the front as the torque was released.

 

How many miles are on this truck?

 

@98RoverGuy
132,000 on the truck, the transmission only has about 10,000.

@ScottR
Assuming it is the transmission, if the the T-case caused it by binding, then it also has issues correct? otherwise why would it bind?

@RoverTech15
If it was the front diff, I should be able to remove the front drive shaft, lock the CDL, & drive forward with the rear axle only correct?

 

Correct, I'm all for the earlier post that has you checking for noises in the driveline by rotating the parts by hand. The front wheels should turn the front prop shaft free and smooth. Same with the rear.

Inspect everything in the front, the CV's the hubs, the diff. Check it all for signs of stress, or binding. Get the transmission into neutral and lock the t-case into low and high and perform the same tests, everything should be smooth.

Something caused this lock that you felt. And when it locked something weaker snapped when it happened. Just working though this menatlly the following appears to be fine:

1. transmission output shaft to t-case input (reverse works)
2. t-case can be shifted into high and low if I'm reading correct
3. power is transferred to wheels in reverse, is it to all four?

Given the above you have a working t-case, to some extent anyway. The question is now if the transmission is supplying forward power to the case.

Since you can shift in and out of reverse the pump is likely working. If you have no forward gears as at all we can rule out things like the governor valve and linkage. Also probably not the bands or valve body either, but those can break as well.

You have to figure out if your getting power from the transmission to the t-case in forward gears. Then we can narrow it down to a shifting problem or a broken layshaft or etc.

 

The main problem does appear to be my transmission, though I suspect my t-case is not in the best running condition either. When I turn the front wheels with the transmission in Neutral, the drive shaft does turn with no resistance or noises. The plug on my transmission was full of metal shavings.

 

Thats bad, sorry to hear that. The upside is this, you should be able to get a trans and t-case together used for fair price. They are a bit heavy and awkward to replace, but very doable.