In need of some advice. So A week ago I noticed a what I thought was a miss. Turns out definitely not a miss but a shudder. 2014 5.3 with 6l80 and 120000 miles. I'm thinking this is torque converter related????? Will a flush help? Or do I bite the bullet and replace whole tranny? Oh also trans has been shifting ok. Once in a while I will get a hard down shift. This literally just happened over night. I have tried shudder gone stuff in red tube. I did filter and 6 quarts new fluid about 18 months ago roughly 30000 miles. Any advice/ help would be much appreciated. Basically do I spend the 350 for flush or 3 grand for new trans and torque converter?