Case 480B transmission banging under a load

(quoted from post at 19:59:54 02/03/20) I'm getting a banging noise sounds rotational the faster the RPM's the more the banging, started out as a click. Today under heavy load was a banging that you could feel in the backhoe, put it in first gear low range and milked it back to the house took shifter cover off, oil is milky, placed bucket down and out triggers down ran it through all gears front and reverse, no banging, put back together drove down hill, no banging, dropped the bucket to load the tractor, loud banging is back.
Got it back to the house, took the inspection cover off by the clutch, front inspection cover from the top, the rear shifter cover again, I can't get the gear selector/ high low range cover off. I rotated the gears around I can't see any that are chipped or broken, nothing looks out of place except the milky fluid.
This is my first backhoe, I'm very new at this, any help would be very appreciated

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(quoted from post at 09:00:01 02/04/20)

(quoted from post at 19:59:54 02/03/20) I'm getting a banging noise sounds rotational the faster the RPM's the more the banging, started out as a click. Today under heavy load was a banging that you could feel in the backhoe, put it in first gear low range and milked it back to the house took shifter cover off, oil is milky, placed bucket down and out triggers down ran it through all gears front and reverse, no banging, put back together drove down hill, no banging, dropped the bucket to load the tractor, loud banging is back.
Got it back to the house, took the inspection cover off by the clutch, front inspection cover from the top, the rear shifter cover again, I can't get the gear selector/ high low range cover off. I rotated the gears around I can't see any that are chipped or broken, nothing looks out of place except the milky fluid.
This is my first backhoe, I'm very new at this, any help would be very appreciated

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I would look at the bull gears , you could look through the plate on the rear of the transmission casting where a pto would mount , the shuttle /dual range cover will come off if you shift the dual range into neutral and put the shuttle lever in reverse, the shuttle shift fork is up under the casting keeping you from picking it off, likewise to reinstall it the shift collar must be in reverse and the fork clear back in reverse position.

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