Rough transmission shifts

SAMUEL JAMES LYONS

MEMBER
2009 FORD FUSION
2.3L
4 CYL
2WD
AUTOMATIC
64,000 MILES

I have got rough shifting like a leaping forward almost feel when shifting from first to second and second to third and downshifts from 5-1/2 it is the FNR5 fivespeed auto-transmission. I have changed the fluid with Motorcraft FNR5 fluid and the filter with a Motorcraft one as well. Really unsure as to what to do next. It also has a rough vibrating idle at stops while in gear not sure if they re related. Along with transmission services I have replaced the spark plugs and all three motor mounts with new ones minus the main one on the passenger side which was a used OEM one. Not sure what to do next. No codes and no check engine light or wrench light.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,968 POSTS

Hello,

It sounds like you could have one of two problems. When the transmission shifts hard it could be an internal pressure regulator spring has broken or the car is seeing itself as going up a steep hill all of the time. So the computer is being fooled. This can be because of a partially plugged catalytic converter or a MAF sensor that is a little off. Here are two guides I think we should try to confirm the issue:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

and

https://www.2carpros.com/articles/mass-air-flow-service

Please let us know what happens.

Cheers, Ken