Clicking Noise From Transmission



I own a 1987 GN with 47,000 miles. Recently it started producing a cliking noise from the transmission that appears to be related to rpm. The niose is louder when the gear lever is in 1, 2, or R. It as also louder when the TV cable is pulled. A pressure gauge showed the presure fluctuating radically. The needle was a blurr. It still drives OK, but I'm keeping driving to a minimum. I think it may be related to a problem with the transmission pump or the valve body. Any ideas?:confused:
What is the service history on the transmission?

Has the fluid and filter been changed recently?
Possible broken pump vein ring. All classic signs including pressure flutuations. Cracked rotor and/or neck of converter isnt ruled out either. Thats where I would look. First ck flexplate and converter bolts real good. then proceed.

Fluid and filter were changed, with no effect. There was a bit of black sludge and a small ammount of metal flakes in the bottom of the pan.