Transmission & mechanic recommendation

I can’t seem to find a reliable transmission shop in Durham, NC that is reasonable - anybody have a recommendation of a shop/mechanic they trust in Durham? (or someone I should avoid)

I have a 2000 buick lesabre with only 35,000 miles. It now shutters, shakes at around 1500 to 2000 RPM’s. When I take my foot off the gas, or pump the gas pedal to increase RPM’s & speed the shutter goes away. However, can’t maintain a steady speed without the shutter.

Dealership says it’s the torque converter breaking apart - wants min. of $1,800 to fix, but may need an entire re-build or put in a re-manufactured transmission for much more.

I’ve also had an independent mechanic say he’d just drop the pan, change the filter, gasket, fluid and put in additive for $375 (this sounds like a lot of money for something that may not really fix the problem)

Is this really a transmission problem, a simple sensor, or something else?

And what were the diagnostic results? Were there any codes? You are the victim of anecdotal diagnosis.

No engine light and no codes. The dealership drove it, said it was the torque converter; Independent guy (who I’ve just found a flamingly bad comment about on yahoo from a previous customer) drove it also. Your point about anecdotal diagnosis is also why I’m asking for recommendations of trustworthy mechanics.