Help with non-toyota vehicle.

I know it's odd to ask questions about a Ford on a Tacoma forum. But I'm at a loss. Any help would be appreciated.

2009 Ford Expedition
5.4L 3 valve, 4wd, automatic transmission.
Good maintenance
296,112 miles

Symptoms.

When first starting up the vehicle, then put it in reverse there is a noticeable shudder that gives a mild shake to the vehicle. If you put it in neutral, the shudder goes away.

It only does this when the vehicle is doing it's first cold start of the day. If the vehicle is warm, regardless if it's running or you start it back up again, this shudder goes away.

I drain the transmission and replace the transmission fluid filter and refill with the required Motorcraft brand low viscosity fluid every 50k miles, and verify the correct level with the transmission warm per the FSM.

What do you think could be the cause of the issue?

 

Torque converter shutter?

 

Ford,

Sorry had too

Look at the trans mounts, engine mounts and prop shaft first. Easy to check, just get a pry bar and leverage them up and down/ left and right. You may have a warning sign here of a valve body issue or stall converter starting to fail.

Since it is a 4wd there have been instances of transfer case bearing failure. Not fun.

 

Just so folks know this is happening in 2wd, honestly I rarely use the 4wd on a cold start up as it's parked in my garage. The 4wd works fine though.

 

I might be wrong but I think the transfer case is connected to the trans via direct drive.
Seen some odd things over the years.

Service manual can help, just remember to think outside the box when looking for vibrations or electrical issues.

Had a vib in a Kia once that ended up being a loose Phillips screw...

 

I would say something with the torque converter. Had an 06 F150 that would act funny once in a blue moon. Never let me down though. People will say “ford” problems but my mother in law has a 2007 expedition with close to 300K miles in the damn thing is a tank. Drives it everyday and trips to the beach every year.

 

I’m amazed that a Ford can get 300,000 miles

 

Is it a surging? Does it throw a check engine light? If so what what is the code.

My buddy had a v10 mod motor like you have, it was the alternator causing all sorts of wacky stuff like that due to some weird EMI.

 

Had a '96 F150 Reg cab 4x4 302cid Auto...the drive train was bullet proof. never used a drop of oil. 289,000 miles
Jeff

 

Everything goes in the 2nd gen forum, even Furd problems

 

Your MIL is a tank, or her truck?

 

It might be something simple, like a low idle speed when cold due to faulty IAC valve or vacuum leak. I've owned many Fords and they always seem to develop vacuum leaks at a certain point. Any pending or active diagnostic codes?

Regarding Fords and high mileage, it wasn't unusual to see a Crown Vic fleet vehicle (taxi, cop, transport, etc.) hit 400k or higher with the stock drivetrain.

 

Lmao. Her expedition!!

 

If well maintained they will last 400k..I plan to get at least 350 out of mine.

I removed and cleaned the throttle body. It does not have a separate IAC valve. The alternator is brand new and Motorcraft brand so I do not believe that to be the issue. Hopefully it is not torque converter those are decently expensive and a pain in the butt to replace.