I have almost 30,000 miles on my F350 6.0 the manual says to change trans fluid at 30,000. the fluid looks & smells good My ? is does the fluid really need to be changed that often about 10,000 miles towing my fiver weight 11,000

 

If they recommend it I would do it. I probably change trans filter and fluid moer then most. But on my ladies95 intrepid, they have notorious trans problems, I do it, and it pulls stronger then when she got it

 

I've changed mine every 30K, I have 90K on the truck now and have had no problems. My truck is an '03; I know Ford had a problem with the '04's due to a clip on the reverse gear failing leting the shaft grind into the casing (sIt). The word was you could see the metal filings on the remote filter element. Since hearing that, I stuck with the schedule.

 

Yes, you should change it.

Change the diff fluids and transfer case fluid while you are at it.

 

I had mine done on Tuesday. It ran me $300. The flushing system the dealer used on my truck (07 PSD) runs a detergent additive through the trans, lines and cooler for 30 minutes. There were sight glasses on the machine for the new oil and the old oil. There was a slight difference in color between the two.

I had my truck for a year now and pulled my 9,000 pound 5er for about 5,000 miles so far, the rest is highway miles, and it was dirty.

So in my opinion, get it done