[05_HARLEY_F250]

I'm not sure if the title is right, I'm not sure how to explain the issue but i'll try.

A few weeks ago I changed the exterior trans filter for the first time in a couple years (I know) so now after driving aggressively and getting everything nice and hot I get a slightly different noise at idle in drive when I pull into my driveway I can't describe the noise, it's not quite a whistle or a chatter or even a hum, sounds maybe like a idler pulley with a bad bearing.

It goes away when I put it in park or everything cools down and it isn't heard in neutral or reverse.

It can also sometimes be heard when I let off the go pedal at speed and the truck returns to idle, such as slowing for a stop or turn from highway.

the truck drives and shifts normally, someone told me I had to drain the torque converter and put some additive in, didn't sound right so I'm asking you guys.

 

[Ford06]

Did you change the fluid when you changed the external filter? Only a portion of the fluid is changed by draining the pan, so you might try changing the fluid again. And did you put the correct fluid back in? It uses LV or SP fluid only.

 

[05_HARLEY_F250]

No fluid change since 100k

Truck is currently at 155k

How often does the fluid need to be changed? I was under the impression that the purpose of the external filter was so you could change it without changing your fluid all of the time.

It may be due for a change, I don't know.

 

[Ford06]

Change it. I cannot remember the interval, but I am pretty sure you are well past it. You only get part of the fluid on each dump, so you need to do it several times to dilute it down to pretty much fresh fluid.

 

[05_HARLEY_F250]

I drove it on a three hour trip over the holiday weekend and seemed to lessen the occurances of the sound. Maybe tranny fluid in one area was getting stale

Do you know if there is a drain plug on the torque converter?

Someone told me it may have one.

 

[Ford06]

no, you cannot get it out without a Ford hot flush machine.

 

[05_HARLEY_F250]

The conclusion

For anyone interested, following, or doing searches in the future.

It was in fact the transmission making the noise, Ford did a hot flush for a couple hundred bucks the truck no longer makes the noise.

After a search (within this forum) I found that it was in fact past due and thanks to the skilled people here at the diesel stop, I was able to save a lot of time and money.

Thanks guys!