I wanted to run this past the board and see what others might think. I did comunicate this with a retired transmission engineer on another site and he thought it would work but he did not help with any speciifcs.

My truck is a 2011 6.7 dually and has 21,000 miles. Just about all of those miles are at max GVWR. I only use it with the camper so I don't put a lot of miles on it. I am thinking about how I will service my transmission fluid. I know Ford reccomends a 150,000 mile change interval but I am not comfortable with that.

What I would like to do is drain the pan and refill with the same amount of new fluid and then do this on a regular basis, say 20k or 30k miles. If I did it during a engine oil change it would be very convenient. This is the recommended procedure for my Honda Accord according to two different servicing dealers. Some questions I have are:

What is the total fluid capacity of the transmission and torque converter and how much fluid comes out when you pull the plug on the transmission pan. If I new this I could make some calculations on how often I might drain the pan and refill.

 

The capacities are in the attached. It looks to me like you can tell early vs late build by what the dipstick looks like.

 

You are on the right track. I usually drain the 8qts out of the pan every 15-20,000 depending on how hard I am on it. I buy the Mercon LV at O'reillys for around $4 a qt. It always comes out clean and bright red. A trans builder told me once that the most important thing is to keep the fluid clean and the temps down. I did the same thing with my '05 F250 with the 5r110. It lasted 276,000 mostly hard miles. The only reason I rebuilt it then was due to hard downshifts and I didn't want to take a chance on a month long trip. Good luck I hope this helps.

 

Thanks guys, and I appreciate the pdf.