t18a whines on 3rd and 4th

Hi all! i just finished rebuilding a d18 tcase and put it back on.
I took off the jeep for a test drive and i noticed that i wasn't happy at all.
The problem finally wasn't from the tcase because it wasn't the same whinning noise that i was hearing before the rebuild.
When i got back in the garage i put the tcase to neutral and while the engine was running i was changing gears in transmission.
1st, 2nd and reverse was running fine with normal gear noise but in 3rd and 4th the noise was horrible.
It's worse than the whinning of the tcase prior to rebuild.
Any opinions what might this noise is?

 

I'd guess possibly mainshaft bearing. In 3rd and 4th gear that bearing is turning much faster than when in other gears. Possibly transfer case input bearing also.


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That what i was guessing too but even in the other gears with more rpm you couldn't here any kind of grinding. The noise isn't exactly whinning as it is from the tcase.
And the other thought is why i can here it after the rebuild of the tcase. The noise is too loud to be covered from the tcase.

 

Was the transfer case input bearing replaced?
Also make sure the transfer case input gear nut was torqued correctly.


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You mean the output bearing of the tranny?
because the tcase was totally rebuild, replaced all bearings, gears, intermediate shaft etc.
Also i removed the adapter of the tranny where the tcase bolts on to remove a broken bolt and then back on.
I didn't do anything else from transmission side.
But i didn't notice any movement of the output shaft of the transmission when i removed the adapter.