Currie 9” Rear-end

by chance was the axle overfilled with gear oil ,, had a similar issue with a rebuilt complete 9 inch axle i sold , all seals were leaking , turned out the customer overfilled the the unit ,,, not the 5 pints required. pull the fill plug with the car level to see if any leaks out. if not check the vent to see it it is clear. Currie does build quality axle assemblies and synthetic oils are not the issue.