I know this case is "chain driven." Does the chain only drive the front output shaft? When in 2wd, is it a solid connection thru the input shaft to the rear output shaft?
I'm trying to find some "slop" in my drivetrain and I know its not the axles or U-joints.
I guess the same questions could be applied to my NV4500.
It feels like a "pre-load" is present when I push the clutch is in and I drop it into gear. The clutch is completely disengaged and there's no drag.
any play in motor mounts and t case mount will transfer as "slop" also u joints can wiggle solid but be bad, its not as frequently the case where it wouldnt wiggle but still be bad, but its possible. to my understanding, applying a load to the u joints and inspecting can show the true situation. which is a little difficult obviously, but something to consider. maybe have someone on the ground observe and listen to each u joint while doing back and forths
also is your shifter properly adjusted? to my understanding they can be out of adjustment and it can do funky things
when you say you know its not the axles, what do you mean? idk what axles you have but any meeting point of power transfer can contribute. do you have good wheel bearings? even rear ones :O
do you have a sway bar by chance? idk how they work on squares but you can improperly install one on a car and if you apply more force to one swasy bar link it can be weird behavior. do you have any bent shafts
how about slip joints or two piece axles with splines? Perhaps not greased and wearing down or sticking
do you have hydro clutch? Does the pedal to the cylinder have any play or all tight? Does the doo-hicky that controls the fork thing have any wear, bent, maybe bushings worn of some kind.
do you have a engine whos cylinders are contributing equally?
dumb question but whats the fluid in your trans and t case looking like?
How are your leaf springs? Pinion angle?if you put 1000 pounds in the bed does that change the behavior at all
do you have manual locking hubs? do they freely engage and disengage?
Ball jointssss
im out of ideas