02Screw

I have an 02 supercrew 5.4 121k on it 4r70w tranny recently changed the tranny fluid due to a hard downshift out of overdrive into 3rd. Whenever I am in overdrive and initiate a downshift there is a very hard thud felt through out the truck mainly in the drivtrain. Sometimes does it when going into overdrive too around 60mph. Changed the filter while I was in there and put a quart of lucas transmission slip fix along with the mercon v and the problem is still there. Just wodering what you guys think I got a feeling that it is the torque converter but I wanna make sure it isnt something dumb. I am 100% postive that it isnt cop's

02Screw

Ok narrowed it down on my way home from work it only happens when the torque converter is locked up. Anyone have any similar problems? Solutions?

ohenry1946

Don't have an answer for you but have exact same problem with mine. Was going to change fluid and filter next weekend but sounds like that isn't the problem.

02Screw

Well I noticed today that the downshift isnt as hard as it was before I did the fluid change with the lucas. Which makes me think that the valve body had something to do with it. Maybe ill look into throwin a valve body at it and see what it does. A valve body is definitly cheaper than a whole trans job.

rsteedly

My F150 has a thump in drivetrain when downshifting from over-drive to 3rd. Does anyone have updates on this? I'm trying to determine if the transmission will last and if so-how many miles?

MrXLT

I hate to be the new guy AND revive an old thread but did anyone ever find out the issue, if there is one? I just bought a 98 Expedition and it's doing the same thing.

I'm a little wary of these transmission as I'm coming from a 98 Crown Vic with the same 4r70W that was maintained perfectly yet already has a worn valve body (hesitant shifts when cold) at 160,000 miles so I wasn't pleased to see the "U" code on my door which meant I just got another one.

Thing is this one shifts beautifully, even better than the Crown Vic when it's warmed up. Upshifts, downshifts, lockup; everything is smooth and silk and absolutely perfect. It's just that little "thud" going out of OD every now and then.

clsale1999@gmail.com

I have the exact same problem on my 80,000 mile 1998 F150 4.6L. It's driving me crazy. Did anybody ever get this diagnosed who can shed some light on this problem?

TtStubbs

I have the same issue on my 02 F150 5.4 V8!! Getting annoyed with it. I noticed it shifts a lot harder in cold weather. No issues other than the hard downshift into 3rd. Anyone figure out the problem?

KB Cool

Mine does it too. It feels like the transmission is sliding forward when coming to a stop. Doesn't do it every time though.