when my trans is shifting into OD in 4th around 40mph I will do a sudden drop to around 1000rpm and then when trying to accelerate it will feel like it’s struggling like the engine is chugging, sometimes it will shake if I put my foot on the gas hard and sometimes it will kick into gear and go smoothly. With OD off it does not happen and shifts normally. Any thoughts, I was reading and the only thing I could find was the manual lever position sensor could be causing the issue.

 

I think it might be the clutch failing in the torque converter. I know that sounds like an oxymoron, but there is a set of clutch plates in the TC that make it lock up completely so there is no slippage like automatics had in days past. If memory serves, the E4OD only locks in 3rd and 4th and has to be at or above a minimum speed. Something along the lines of 30-35 mph. TC lock will occur about 1 sec. after the shift. In that generation of trans. it almost feels like a double shift under light to moderate power. I think your clutches are either worn or glazed and slipping. Brake application causes the clutch to unlock, so try this; with your left foot, apply enough brake pedal to activate the stop lights but not actually apply the brakes. Now drive through the conditions that cause the problem and see if it persists.

 

 

 

That actually sounds normal, 4th gear engages anywhere from 35-45mph depending on how hard you're on the throttle. When you punch the throttle at that speed range it will likely downshift to third gear. I think you're doing fine my dude, that's how my E4OD acts. Could be an engine problem up front causing a lack of power but the shifting sounds ok.

 

 

I really don't think that's the problem.
Bingo! Misfire is likely the problem.

The other problem is that the software in these early vehicles upshifted to overdrive at too low speed. This causes chugging and sometimes misfire. If you were to turn off overdrive at lower speeds I think you'll never see this problem again.

 

 

Yes it can.