I have a 4.0 with automatic trans and 3:73 ration. tires are 31/10.5/15 inch
I have a Tj 2 inch lift and I do not get any vibration under acceleration, or de- acceleration, in fact it is very smooth.
Now for my question, when my trans shifts into overdrive at about 45 mph my engine RPM drops to about 13 to 1400 RPM sounds like it is lugging and I get a vibration from the engine that radiates back through the drive train and I can feel it in the floor. As soon as I hit the OD button the vibration is gone. What is causing this, is the engine out of balance, or is it normal?