I've got a 2000 F-150 4.6 5-spd 4x4 with about 134,000 and some miles on it. Just recently I have started to hear a "whining" noise when in 5th gear doing about 60 mph, if I let off the gas after a fraction of a second it quits and then returns when I get back on the gas, if I am in 4th gear doing 60mph there is no "whine". The "whine" continues in 5th gear above 60mph and may in fact become a little more pronounced, but in 4th gear at higher RPMs and speeds no "whine" thus far that I have noticed.

It sounds as if it is coming from the transmission tunnel but it could be me hearing it there.

Anybody got any idea what I may be in for? The clutch doesn't slip and the majority of those miles are highway. I have never really dogged it off road as I have another toy for that.

 

You can try some fresh fluid in yer M5OD-R2. Four quarts is worth a shot. I've always just used plain Mercon, but others have quieted down noisey units with GM Syncromesh brand fluid.

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