Mark inspired this one.

Got a 2000 f250 4r100, I was told not to flush my transmission. It would only bring me problems.

Story: I was pulling camper in the hills. 10% plus grades 25 mph (2000-2300rpm) it over heated.

Went out and bought a 26 row 6.0 cooler for it. Was going to put it in this weekend. My back went out never happened.

Truck went transmission shop on Monday. To have them look at the fluid, they call me fluid is burnt, oil level correct, has a slip-bump from 2-3 and 3-4????????? 40$ for a test drive and **** I already knew.

Can we drop the pan. Yes. Excessive debris in pan=overhaul. 80$ more to drop pan and clean it out, put old fluid in.

I have always felt that the rpm's ran high before it shifted. I never felt hard shifts. It doesn't shift seamlessly unless I'm on the throttle. When it over heated the OD light was flashing(how hot is that?). It took it a little bit longer to go from P-R-N-D and vise versa. Let it cool down, No problems.

Unless I tow then it starts acting up being slow between gears. I think this is happening because my fluid is shot and is overheating easier now?

 

I flush mine every 30k ish, I also change my oil every 5k ish. Old oil doesn't do what it's supposed to do. Why leave it in there?

 

You need to pull the codes...the flashing OD light means that a fault(s) have been detected in transmission.

 

The OD light hasn't flashed since it over heated. they ran it for codes and only came up with the AIH code, that's because I deleted mine. No other codes. John I agree with you. So if I flush it my self, then that is less harsh then forcing it out with a flush machine?

 

The codes are there...when the light flashes it indicates that codes have been stored. My guess is they tried to pull with a cheap scanner. That won't do it. Ford dealer or someone who has a scanner capable of taking the codes from our trucks.

 

The OD light flashes at 270°F. You may or may not have reached that. Unless you read the codes you don't know if that is the reason the light was flashing. If they read codes and there were no transmission codes that means they don't have the right scan tool.

Here is how I recommend changing the fluid:
ATF CHANGE.

 

In between the Overheating and the transmission shop was a couple weeks.
During that time I did my glow plugs and a Quarter shim on the harness on the drives side and haven't had time to get the right side down. Which means I disconnected the battery that probably erased it?

 

Mark would know for sure, but I am relatively sure that the codes stored are hard codes and will not erase from the PCM memory due to battery disconnect. The code reader will be the way to erase the codes.

 

Here's what I do>

Changing ATF Fluid in a E4OD and 4R100 transmission | Ford Trucks

I have the bypass filter on the transmission, so I don't change the pan filter anymore, and a John Wood valve body.

It works great! props to Mark K!!

 

Disconnecting the battery will absolutely erase the codes.

 

While I didn't stay at a Holiday Inn Express last night, my money is on this guy.......just sayin', the guy knows the 4R100 better than it knows itself.....

In related news, Mark......isn't 270 degrees way above where people usually freak out as I see many references to 215-230 degrees in old posts etc.? I would love to know your thoughts.

Thanks

 

I read your write up thank you pretty straight forward.

I know it got hot with or without a code something was smoking I couldn't see where it was coming from. I haven't had that happen since.

So looks like this weekend I will be putting a 6.0 cooler in it and changing my fluid. I was really torn between the 26 and the 31 I got the 26. All I read said the differents is about 10 degrees. Is the return line generally the same size as the cooler line 3/8"

Better put the money on the knowledge.

I guess I'm still worried. So my old man had a '97 f250 I don't know what transmission it was, I would assume the 4r100 is a better transmission as technology get better not worse. It went out twice after he flushed it each time.

It will always be in the back of my head.

 

The theory behind transmission flushes causing problems is; older transmissions that have been beat to hell and back and have never had the fluid changed have alot of sludge holding things together and keeping it working. Fresh fluid acts as a detergent and breaks down that sludge and transmissions go out.

Maybe this was the case for older transmissions from the 60's or so? But it doesn't make sense to me.

 

I think it's a case of correlation not necessarily indicating causation. Lets say Joe Dumass severely overheats his transmission, but the car still drives for a while. He takes it in for an oil change and the mechanic tells him the fluid is toast and recommends flush and fill. The damage has already been done, but when the tranny finally grenades a week or two later, Joe Dumass concludes the new fluid must be the cause. Even though the flush wasn't the cause, it seems to correlate with the failure. After all, the tranny was working fine with the burned fluid, right?

Then he tells two friends the flush destroyed his transmission, and they tell two friends and they tell two friends, ad infinitum. Yet another urban legend is born.

 

I'm worried the damage is already done. So new fluid now, New tranny later.

Any suggestions HD4R100, 40edo or I have no clue what that is.