5R55S Transmission service maintenance interval

[Desert_Flyer]

I've been searching these forums for some hours and see a lot of different viewpoints regarding transmission service intervals but nothing specific to the 5R55S. I just bought our 2006 Explorer XLT V6 with only 25k miles and want to keep it in top shape for many, many years. Right now, it will be my wife's daily driver for a few years. After that we will keep it as our tow vehicle (2,000 lb tent trailer) until it drives itself into the ground! We only tow about 2 - 3 times a summer for camping. I have set up a maintenance schedule for all the usual things but am stumped when I come to the tranny. For the V6 with 5R55S, Ford says 150k mi for fluid and filter change which sounds nuts to me. Fluid level checks every 15k sounds ok. Since it is not a high mileage vehicle, my plan is to have fluid exchange/flush every 30k miles and then a filter change at 150k. Does this sound reasonable?

Also, I plan on having the rear diff fluid level checked every 30k and replaced at 90k. Is this OK?

 

[Flag Gibby]

Assuming that the V6 is a 4x4 model, I wouldn't worry about the rear differential fluid it is the front differential fluid that needs to get changed to a good full synthetic like the rear fluid is (change it and forget it until 150k miles or so). As far as the transmission, if you towed more frequently I would change it every 30k miles but a flush starting right now and then every 60 should be sufficient until around 100k when it would be a good idea to do the filter (use only the correct spec. fluid anything else and it will shift funky, I use Moblil 1 full synthetic ATF). There is no easy way to check the fluid on these transmissions (no traditional dip stick) and no need to unless it is having shifting issues. The big thing to be ready for are coolant leaks that can spring up at the most inopportune moments mainly caused by the 20 psi caps on the radiators that run the system pressures higher than necessary, change the cap to a 16 psi cap and you should be trouble free for many, many miles.

 

[Desert_Flyer]

Thanks, Flag Gibby. Mine is only 2wd so no front diff. Do you have a specific recommendation or link to a 16 psi cap?

 

[Tech By Trade]

I did mine when I bought it at 160k Kms, it was pretty brown, not burnt, and it had some shavings on the magnet, not too bad though.

I towed our camper all summer, and put on another 50000k kms, and decided to change it a couple weeks ago. There was nothing for metal on the magnet and the fluid was a little dark but still in very good shape.

They seem to do quite well, my guess is the guy who had it before me never did a service and a lot of that was assembly crud.

 

[fritz24]

Rear diff fluid can be changed until you reached 200k . And for transmission i would not attemp on flushing it since metal debris might end up blocking in your solenoid switch or valve body. Servicing it every 30k is reasonable if you are towing but normal driving do it every 50k with filter change everytime you change fluid.

 

[Flag Gibby]

Thanks, Flag Gibby. Mine is only 2wd so no front diff. Do you have a specific recommendation or link to a 16 psi cap?

Verify, but I am pretty sure that Napa part BK7031712 is a 16 psi cap that fits.

Edit: I cross checked the part number and that is the correct NAPA 16 psi cap that fits.

 

[Desert_Flyer]

Thanks guys!