I have a 2008 Ford Ranger 3.0L V6 with the automatic transmission. About 5 years ago I replaced the engine with a new used one. It is in good shape and I've had no issues with it. About 2 years ago I was driving down the highway, cruise on doing 70 mph, all of the sudden I had no go and the engine free revved. We got off the highway, engine running but no go in any direction. Towed it home put it in the garage and haven't touched it until today.
When I tried to start the vehicle the starter turns but it won't start the motor. When I removed the starter and the access cover to look at the ring gear and flywheel I don't see any damage.
Here is the weird part - I can move the flywheel and ring gear WITHOUT turning the engine. I can grab the harmonic balancer on the front of the engine and turn it and the flywheel and ring gear will turn. - the transmission is in park.
I've removed the pan on the transmission to see if there are any parts laying in the bottom of it - none.
My next move is to remove the engine oil pan and see if there is any damage in the lower end of the engine.
Any clues or suggestions before I do this.

Thanks in advance for any help - very confused!

Devin

 

Welcome to the forum

Your flexplate has broken at the crank mounting point, not a common issue but does happen
Usually indicates a problem with engine transmission alignment, the Dowels on the engine and/or transmission are there to set center line alignment

Flexplate mounted on crank seen here: https://www.agcoauto.com/content/ima..._dowel_pin.jpg

The ring gear is part of the flexplate and starter engages the ring gear to turn engine/crank to start, so if flexplate is no longer attached to crank then starter can't turn the engine

Flexplate can break in the center area so its no longer attached to the outer plate and torque converter, so "no go" as there is no power being transferred from engine to transmission

Seen here: https://forum.ih8mud.com/attachments...0-jpg.1540738/

Flexplate is no longer one piece, Center part is no longer attached to outer part


Park just locks the rear drive shaft from turning so vehicle won't roll away, transmission can still spin, otherwise you wouldn't be able to start engine in Park