Hello all, Thanks for reading and relying to my question.

I have very little knowledge of transmissions but wanted to see if others have the same issue I am having.

I have a 2008 F250 6.4L Desiel with 21K miles (I use the truck as a third vehicle and to pull my 5th wheel) This past year I have noticed when I start the truck and drive it that "something" is slippig. But if I get a few blocks from my house the problem goes away and everything works fine. It seems to take longer in colder weather.

Well yesterday I thought... maybe it is low on transmission fluid. So I warmed the engine up and pulled the transmission stick.

At the end of the stick (in the white plactic part) is brown junk. Not metal, bur rusty looking junk. I cleand the stick a number of times and re-inserted it. Each time I had brown junk on the stick. I can see the fuild and it appears to be a good level and it is light red (as it should be) and does not seem to be burnt. But there is brown junk that I am sure is not a good sign.

Does anyone know what this could be, have others experienced this, and what the issue / solution would be? I have heard / read that changing the transmission fluid may cause additional problems so I am not sure what should be done.

Thank you all for your help / advise!

Eric

 

Changing the transmission fluid NEVER causes additional problems, unless you do it wrong. Doing it wrong would include using the wrong fluid for the trans, adding too much, not adding enough, etc.

I have seen this happen on trucks that sit a lot. The inside of the dipstick tube collects condensation and rusts.

I think what you are experiencing is the engine fan running. The fan clutch needs to warm up a bit before it releases. This usually takes a few blocks, but it will take longer the colder it is. This is normal.

 

Hi Mark,

Thank you for your reply!

Dipstick rust… very interesting. That is exactly what it looks like. Scared the tar out of me. Thank you..

“I think what you are experiencing is the engine fan running. The fan clutch needs to warm up a bit before it releases. This usually takes a few blocks, but it will take longer the colder it is. This is normal. “

I have a high pitch whine; sounds like the turbos are kicking in. It is a very large noise. I can see where it would be the fan. But I simply do not remember this problem before

But I feel like I have less power as well. Would those two be related? (Maybe I simply do not push hard enough on the accelerator because of the load noise.) The obvious recommendation is to let the truck warm up more? Does it “hurt” the truck if I drive it that way for the few blocks?

Thanks a bunch!

Eric

 

You do have less power when the fan is engaged. It can take quite a few horsepower to turn it. It doesn't hurt anything to run like that. I wouldn't let it warm up idling at all. Driving it easy is the best way to warm up.

 

Thank you Mark!

 

Esp. If u have a turbo u need to let it warm up. Most manufacturers of turbos want about 160 deg oil temp. Trans will get warmed by the engine coolant so that takes longer 5 mins idling should do it. U can get extra heat in the trans by putting it in gear while applying the foot brake and raising you rpm a bit , that should create friction in your torque converter. Dont overdo it tho, a few secs max. you definitely have moisture in the trans. Short trips? Rain leaking in the filler tube?

 

The transmission DOES NOT get warmed by the engine coolant. That's a myth. It is especially easy to prove on this transmission since there is a thermostat in the transmission that cuts cooler flow by 90% when the trans is cooler than 165°F.

On all transmissions that have a cooler in the radiator, that cooler is located in the cool side of the radiator. The coolant in that side of the radiator is very close to ambient temperature, even when the engine's thermostat opens the hot coolant is down to almost ambient temperature before it gets to the trans cooler.

I'm not guessing at this, I have measured the coolant temp in the radiator around the trans cooler and the ATF in and out. I've measured this from -40°F to +115°F and NEVER found a condition where it was even close. The ATF was NEVER heated by the engine coolant. It doesn't happen.

 

Thanks guys... One79one71... probably from short trips, mostly garage or carport kept.