No, no Treblig. When I flip the switch in 4th gear it locks up 100% right then and there. The stall speed is not a factor once the converter is in lock-up mode in 4th gear. However, once the rpm's get so low that it down shifts into 3rd (and I have no idea what speed or rpm that is yet) it will automatically un-lock the clucthes in the converter. It will only lock up in 4th, even when there is 12v going to the transmission. Again, at light or full throttle on the highway, as long as it is in 4th gear, with 12v switched on the converter will stay locked-up and provide 100% direct drive, even as low as 1400 rpm (If the transmission doesn't downshift to 3rd). If I switch it off and cruise in 4th gear it will add a few hundred rpm at cruising speed, but once the throttle is wide open it will flash to 3000 rpm and climb with a very low slippage and high efficiency from there. Just as it would in any gear.Treblig, at what speed and RPM does your transmission downshift out of 4th when you are at very light throttle on the road? I got my converter from Precision Torque Converters of New Hampton. It is a Mopar style 4-bolt attaching converter with a GM hub that fits into the 200R4. The hard part was getting it to the correct thickness without the parts on hand to give an accurate measurement. Once I got that. Precision took care of the rest. It is one of their highest quality converters with the same lock-up clutch system they use for diesel trucks that pull heavy trailers. They assured me it is a very efficient converter even when not locked up only allowing a few hundred rpm slippage at light to moderate throttle, but once the throttle is wide open it will flash to 3000 rpm if it's not already past that rpm. In other words, if I am cruising in 4th gear at 2000 RPM with the converter clutches locked up, the lock-up clutches will stop it from flashing to 3000 rpm and acting just like a direct drive manual clutch that is fully engaged.
