My gearbox has had a whine / rumble which everyone I spoke to about it seemed to agree it would be the input shaft bearings as the noise is their at idle but dissapears when you dip the clutch.

I took the box out last week, and dropped it off at a gearbox specialist. Just got a call this afternoon, to say he has inspected the box, and the all the bearings and syncros are spot on. He said the gear teeth were showing signs of wearing through the hardening coating. He also said the bearings were not shimmed properly and the bearings were not loaded up enough. His opinion was that reshimming the bearings and taking up the slack would not likely stop the whining and that its likely to be the teeth causing the nosie.

Im not questioning his advice or anything, the guys supposed to be the man when it comes to gearboxes.

I was planning on putting some Forte Gear treatment in when I refill the box tomorrow, but not sure if its compatible the 2wd gearoil which im told is ATF Dextron stuff.

Should I use the Forte ATF treatment or Gear Treatment??

Thanks in advance