722.355 Transmission Leak

[Cigar Havana]

The automatic tranmission on a 1989 420 SEL, 242,000 KM, is leaking fluid all over the front cage around the torque converter, a 722.355 model. It leaks about 4 diameter circle, when stopped. The torque converter drain nut is on tight and is definately not leaking. I took it to my independent mechanic and he says it is leaking from the top of the transmission, at the forward pump and recommends dropping the tranny, and replacing all of the gaskets and seals, not just the forward pump gasket/seal. He also said the the front pump may be scored and may need to be replaced. I was looking at the breakdown of the tranny, and trying to figure out how the pump gets scored. Is the front pump scoring a common problem?

This leaking only started after the last oil change, which was to synthetic Walmart brand tranny oil, about 3K KM ago.

Comments?