Desperate please point me in the right direction 1999 cherokee sport 160K miles, once on the interstate driving high 60's at least an hour into the trip, it begins to feel like a jerk in the drive train, rpm raise but the actual speed stays the same.....most of the time i can drop back under 50 ish the problem stops.......... the jerking motion is very noticeable.....was thinking if someone on here has a suggestion to tell the country boys here where i live what to check would be most helpful...I cant afford a mechanic to drive it for over an hour to make it happend
also seems to take place after the time period and i let off the gas unexpectantly, or start down a hill that takes some of the drive train strain off the engine

all the gauges are normal except for check engine light is on,,,,,,Please i need your help thanks

 

Scan it for codes. Sounds like the trans is overheating....

 

automatic correct

 

yes auto

 

Sounds like an issue with the TCC lockup. Under 45mph, its not applied. Over that and that clutch is applied for gas mileage. Sounds like either the clutch(which is inside the torque converter) is failing or there is an issue with a sticky valve/solenoid.

 

what he said^^^^^^^^

 

this will also help^^^^^^^