Abnormal Power Loss

[pmesfun]

Lately (past 3 or so months) on my 99 Avalon, there has been an abnormal dip in rpms when I let off the gas in 4th gear. It starts happening around 45 MPH and continues as I increase speed. When this happened especially around highway speeds, the car kind of pulls back, because of the absence of power. I have done two drain and refills this, one in July and one this month. The fluid is red, not burnt and the transmission shifts smoothly.

I have included a video so you guys can see what I am talking about. (skip over to 1:00 to see when it happens.)
Thanks Guys,
Phil

[Youtube:C0_JEX7TUs]

[Youtube:C0_JEX7TUs]

[fenixus]

have you tried turning O/D off to see if same thing happens?

by looking at RPM it seems the tranny slips a gear or upshifts for a brief moment instead of holding on to a gear? not sure.

how come your engine is so damn quiet that I can't hear it at all?

[pmesfun]

Originally Posted by fenixus

have you tried turning O/D off to see if same thing happens?

by looking at RPM it seems the tranny slips a gear or upshifts for a brief moment instead of holding on to a gear? not sure.

how come your engine is so damn quiet that I can't hear it at all?

I haven't tried turning off O/D yet, because if I'm not mistaken, wouldn't that keep the transmission from shifting into 4th gear?

It seems as if it down shifts to 3rd then back up to 4th real quick.

Turn up your speakers and you will probably still won't hear it, but as least your will hear all the clunking from the suspension.

Update:
I turned overdrive off and the problem doesn't exist, probably because it doesn't shift to 4th. Could old differential fluid be causing this?