42RLE torque converter not locking up

[Add!ct!on]

In the past when running 70 mph the tach would run at 2800 briefly then settle and lock in at 2500rpm. A couple days ago the check engine light came on throwing code P0740 so I started paying attention to everything related to the transmission operation and the only thing different is the transmission will no longer settle down to 2500 rpm and lock in. Any suggestions? The local transmission shop wants to do a complete overhaul which i am very reluctant to do.
139,000 miles ’04LJ

 

[LJ Jim]

That's when mine went out, and not locking up was one of many symptoms. Shuddering and burnt fluid might be next.

Low fluid can be a culprit in case you haven't checked.

139k is not the lowest mileage at which one of these has burnt up but maybe a second opinion is worth the hassle.