I have the 5.4L and it has 110K on it. The owners manual I think said that you don't have to mess with the fluid. Well unless it looks burnt or you do a lot of towing. I put about 700 towing miles on it pulling a 5500lb boat for 4 years. The fluid still looks clean and seems to shift fine.

I have read to not mess with it. If I change it, it will never be right and start slipping. I have also read to just change the fluid and filter and that's it (no flush) and it will be fine.

So what is the actual time/miles interval on a 2003 to change fluid?

 

Every 30-35k miles. You are WAY overdue so I highly suggest that you change it very soon. Replace the filter and do a full flush.

 

x2. Change it.

 

All I can find in the owners manual is this:

"Change automatic transmission/transaxle fluid on all vehicles equipped with AX4S,4F50N, 4R100, 4F27E. Inspect automatic transmission fluid level on all other vehicles, if equipped with dipstick. Consult your dealer for your particular requirements."

The intervals look to be 30K like mentioned. I have the 4R70W transmission and that's where the confusion lies. Not sure why that is not listed for 30K interval change. I swear I read something that said if the fluid looks clean and is at the proper level that no additional care is needed. Swear that was in the owners manual but now I can't find it.

For peace of mind I will have it changed.

 

I would suggest a full coolant flush as well unless you have done that within the last 2 years.

 

Yeah I have done the coolant flush about 2 years ago. Thanks