I just purchased a 2010 E350, 5.4, 156k, bone stock cargo van. It runs perfectly, except it has a knock. I traced the knock to the trans bellhousing. Pulled trans, had flywheel checked for cracks, etc..., and put a new torque converter on. Fluid that poured out of old torque converter looked like grease it was so black. Thick nasty black crap. Dropped the pan, which had normal amount of metal flakes on magnet, but otherwise was clean. Cleaned it all up and put new filter on, filled with new Amalie Universal Synthetic tranny fluid and the knock is still there. It runs great. Shifts great, but this knocking is killing me. Anyone have ANY ideas? I'll be your best friend if you can help me figure this thing out..

 

I think it was a big mistake to put the trans back in when the fluid was that bad. That indicates the transmission has failed. I think it needs to be rebuilt.

 

I know what you're saying. It didn't appear that way on the dip stick. And I had to add two quarts to it when I got it. Only place I witnessed the black crap was when I pulled the torque converter and dumped it. Fluid in pan wasn't "that" bad. The thing goes into gear and shifts great. What gives? The "knock" will knock when it's in park too. I originally thought rod, then with stethoscope heard the clanging in the bellhousing of trans. That's why I did what I did. It just didn't help. Knock isn't quite as prominent, but still there for sure.

 

Have no clue about tranny.

By some chance have you pulled the codes on the vehicle?

A very common cause of knocking is using low octane gas. If you're using 89 octane, put a tank of 93 octane in the vehicle and see if that helps. It's relatively cheap right now. (That info was from my long-experienced mechanic.)

 

Yeah thanks James. I get your point on that. Haven't tried to run 93 through it, but this is a different kind of knock and it's coming from the bell housing area. I would think they tranny would be burned up due to the fluid condition, but it runs and shifts so well. No slipping, no goofy anything. Just this "knock". The new fluid, filter, and torque converter have done nothing. Flywheel got check and it's perfect. I just don't get it. Could the starter be somehow hitting the flywheel or something? Somebody said something about a pump that is in the top of the tranny that can go bad. Is that a possibility?

 

Mark, I don't doubt this...I just can't explain why it's running so well right now. No slipping or grinding. Shifts like it's supposed to. Hits passing gear nicely. No signs of failure to me. You think it's just a matter of time before it gives up or something? I'm just looking for opinions. I hate this knocking thing. Driving me out of my mind. Thank you sir....

 

Well just got some bad news. After being given 4 bad diagnosis, I've now been told that the bushing and/or bearing that holds the crank in place (there at the back of the block where it connects to the flywheel) is shot and is allowing the the crank to move fore and aft (frontwards and backwards). The resolution is to pull the motor and rebuild. I have the worst luck, but I believe everything happens for a reason, so the good Lord will hopefully bless this rebuild and I will have a nice, strong running motor. It's such a shame though. There is every indication that this motor was well taken care of its entire life. There isn't even a trailer hitch on the thing, so it hasn't even pulled any trailers. The black nasty crap that came out of the torque converter was concerning, but not there's a new converter in there with a new filter and new synthetic Amalie tranny fluid. Tranny shifts like it's new.
In just talking to guys around here, I hear that this is a more common problem than I realized. I'd never heard of it before, but 4 or 5 guys have said they've run into the same thing on the 5.4. With 156K miles on it, I know Fords not gonna touch it, but I am praying that this fixes it.