I have a 2003 Ford Ranger Edge FX2 4.0 Auto. Just changed the engine and as soon as i have it running the transmission seems to be slipping, I think. It shifts fine but when i get around 40mph, 2000rpm it seens to be slipping. i can give it gas and it will smooth out until the engine itdels back to around 2000rpm driving.If I take off fast or floor it it shifts through all the gears fine.just does it on a normal smooth drive.

 

Does the tran fluid smell burnt?

 

no it doesnt smell burnt

 

You probably need to change the filter and put some fresh fluid in. Maybe add some conditioner or some transmedic.

 

It sounds like the converter is unlocking on you. This would be a pressure issue. I say change the filter too.


If you have some skill, time and extra cash. I would install a shift kit. I hate that soft stock shift, it just creates heat and wear.