4t60e Trans......

i have a 1995 chevy lumina apv 3800 V6. the trans is a 4T60E . when i frist start the van there is a huming sound or a howling sound put van in drive drive it for about 3 or 4 miles and it quits working shut it off for 4 mins and it will be fine for another 3 or 4 miles the van has 94000 miles and run great it has been well maintained fluild has been changed every 6 oil changes in trans. i have added a trans misson cooler but it has been in for awhile.... some one said somthing about a stuck pressure regulator valve causing auto cavitation. if so where do i find the valve thanks

is this valve like the one on the dodge caravan that can be replaced