Ford Repair: e-350 tranny, transmission failure, torque converter

Question
I just bought a used 1998 E-350 club wagon with 130,000 miles.  It has the towing package with a transmission fluid cooler.  I notice a whirring noise when i press the accelerator in drive at speed.  when i lay off the gas it subsides somewhat.  Also, if I put the trans in neutral while moving the noise goes away completely even if i rev the engine in neutral.  The noise does not seem to change pitch at different speeds.  Is this a serious concern?  Thanks  

Answer
Lou-

  When I think it's safe to assume that the whirring noise is most likely friction.  Where the friction is occuring...that's not so easy to pin down.  From your description, my money is on the torque converter.  Think of a torque converter like a clutch for an automatic transmission, except it uses hydraulic pressure rather than friction to transfer power from the motor to the gears.  That's just a guess, but it's better than nothing I suppose.  First thing I would do is check the condition and level of the fluid (please remember that to check transmission fluid you need to have the motor running).  If the levels look ok and the fluid looks good, I'd have a transmission shop take a look at it.  It doesn't sound like you're about to face some sort of catastrophic transmission failure, but it's certainly something I'd have looked at.  Hope this helps.

Steve