my 68rfe has never downshifted while the exhaust brake was on. in fact when the e brake does work if i upshift manually to pick up a little speed the brake will not activate itself again no matter how much speed the truck gains or how high the rpms go. and then if i gear back down the brake still won't reactivate. i usually have to turn it off with the switch and try again. that works about half of the time. the other half i have no operational e brake. i expected it to work like my '05 did with the pacbrake. by that i mean when it's turned on it actually works till you turn it off of hit the gas. but this e brake works at it's own discretion. maybe if everyone lets them roll down hill with the e brake on at 10,000 rpm and the dealers get to replace a few hundred engines the e brake fix will suddenly become more of a priority.