Hey guys I've got an ongoing long term problem with my 2004R. It's now got over 210k miles on it. Its had an issue since about 100k miles ago after driving it somewhat hard in hot weather, then parking it for a little while, it would not want to engage in reverse. The problem went away almost completely after getting an auxiliary trans cooler, and getting the lockup torque converter working again. The odd time since then (about 6 years ago) it still doesn't want to go into reverse but very rarely. Yesterday the problem came back but it isn't that hot yet, and I wasn't driving it too hard and it wouldn't go into reverse or drive until I gave it a couple little revs and brought the pressure up enough then it worked fine. Also lockup works fine cold but once the car gets hot if I have to accelerate harder to pass or i slow down, it doesn't want to reengage lockup a lot of the time. Everything seems to be heat related. I'm thinking its getting a bit tired, the last 100k miles have been a lot of highway but also some very "spirited" driving and a lot of passes down the 1/4 mile track. The fluid is still nice and clean still, has been changed regularly and never gets dirty. Shifts are fairly hard at light throttle and normal at WOT, no slipping or shuddering or anything bad like that. Any suggestions? Oh ya and its Ford Mercon 5 fluid in it now with about 12k miles on it. Thanks.