1st of all thanks to everyone for many great posts on this site regarding Explorer transmissions. I have 98 Exp XLT AWD with about 168K miles, NON SOHC. The problem I am having is it will NOT engage reverse or 4th/OD. In reverse the backup lights come on, but the engine just revs. No engagement, noise no movement, nothing. (acts like it is in neutral) It will move and pull fine in 1st, 2nd, 3rd, but not 4th & OD. If it shifts in into high gear with the OD button on or off it will not pull...just revs the engine. Both reverse and high gears act like they are in neutral. If I drop the shifter down into 2 it will engage and start pulling. Same for 1st. It slow down enough while in "D" it will shift back to a lower gear and engage again. I have read thru several posts and suspected the Valve Body gasket, Reverse Servo or one of the TCC/EPC Solenoids. So I purchased rebuilt Ford VB with all the solenoids and separator plate and gasket as an assembly. Poked a long Phillips screw driver up in the rev servo to check the low/rev band and it seemed ok....it would go stiff after I pushed in another 1/4 to 3/8 in...so assumed the band is ok. (Also noted my reverse servo did not have a spring behind it...seemed odd) Installed the new VB and torqued the VB & servo bolts to 87 in/lbs. Also got new reverse servo O rings and replaced them. Installed new filter and pan gasket. Pan did have what I call a medium about about of gray friction material in it. Put about 7 qts Mercon V in it aand warmed it up for few min. Got in to test it....and nothing has changed. It has been slow to go into reverse for the last 20K miles and downshifting a little rough (just not smooth) for about 50K miles. I have changed fluid & filter around 60K and 110K mi. I have used it to pull fairly heavy boats, cars, etc for years. After reading some the posts I am suspecting the reverse and high clutch is shot. It the only common link I can find between rev and high gear. As it is "applied" in 3rd, 4th/OD & reverse according the Clutch Application Chart i found posted. The 5R55E seems to be a 3 spd tranny with two of the gears using overdrive to get make it a 5 spd. (1st+OD=2nd & 3rd+OD=5th) If I had a pressure issue... I would suspect the VB replacement to correct it or at least change the symptom. Any suggestions on what you suspect or how to confirm my thoughts?