WHEN IT'S COLD,USUALLY BELOW 50degrees the torque converter locks and unlocks, until it finally does lock. The other day it was about 60degrres and it didn't do it at all. 97 2500 cummins w/ 150k

 

It is normal for the t/c not to lock up when the tranny fluid is cold.<br>You can help this by leaving the truck in &quot;N&quot; when warming it up in the mornings.<br>It seems that these trannys (in stock form) dont circulate fluid while in Park.<br>However, they will circulate fluid if left in N. <br>Also, the opposite is true. <br>When you go to let the truck cool down before shut off, leave the tranny in &quot;N&quot; to allow the fluid to circulate and cool.<br><br>Rich.