I just pick-up a Raybestos Magnafine filter, It says on the filter to replace every 12 months or 12,000 miles. Here is some info from the Magnafine Site: http://www.emergingent.com/magnefine/faq.htm

 

Update: before I could change the thermal bypass block, my truck's overdrive stopped working. Gears 1-3 worked fine, the shift into OD was like shifting into neutral. With the OD button set to off, the truck operated normally.

Prior to this, OD would be like a neutral shift if the trans fluid temp exceeded 180º. Below that temp, it would operate normally. Anyone have any idea what could have caused that?

Anyway, to make a long story short, I got a Motorcraft reman trans installed by the dealer under warranty at $0 cost to me.

I know the "lost overdrive" problem can be caused by a broken snap ring on the OD servo, but this snap ring wasn't broken and apparently there were several serious problems with the trans. "Valve body failure, cracked trans housing" are the causes I was given by the service writer.

So now I have a rebuilt trans with a 3 yr, unlimited mileage warranty. I hope I got a good one.

Truck is a 2008 5.4 4x4 Lariat with 57k miles, in case anyone was wondering.

I hope your problem is just a sticky thermal bypass! Have you had a chance to change it yet? Any difference?

 

Yes, changed it about a week ago, so far the temps have behaved themselves. It would get up to about 155 (after a while), then would drop back down to 147-150. So I at least know it's working.

 

Netwurker, thanks for this post. I did this and immediately notice the benefits. Thanks for taking the time to video.

 

Net Wurker...
Great article, excellent video... I was looking forward to install a Magnefine filter this very next week.
I have a 2006 STX, SuperCab 2wd, 4.6 V8, the door sticker says Transmission Code "A". I understand it has a 4R70W transmission (?!).
My question is:
How can I know which is the tranny return hose so I can install the filter? Would this be the same as in your truck's?

 

I believe that's a 4R70E, not W. Slight difference.

 

You're right. That's tranny code "A".
I was checking the FSM(on CD) last night, it has a page where it states about installing a tranny filter in-line, but I didn't state which was the return hose.
It says basic information on the installation for a tranny with an oil cooler and also for a tranny without oil cooler, but only about the direction of the filter, clamps, little hoses, and miscellaneous. It does not make clear which line is the return line or how to determine which one is it. The diagram is kind of blurry.
Is there a failsafe way to determine which is the return hose and the direction of the fluid? From reading other posts it seems to me it goes from the tranny, driver's side, to the radiator/cooler(if applicable), out to the tranny, passenger side.
I just want to make sure this is correct for the 4R70W.
In one of the other posts I read a joke about driving the truck for an hour or so, park it without turning off the engine getting underneath, and grabbing both lines on both sides of the tranny, one with each hand, and posting a pic of both hands for the guys on the forum to determine(lmao)...
Honestly, I'm starting to consider that option...
Please let me know about the return hose.
Thanks

 

Regardless of the transmission code all AODE/4R70W/4R75E 1995 and newer have the cooler return hose at the top of the transmission case.

 

Got it. Will work on this tomorrow.
It should work out fine.
Thanks to all!

 

Great post. Good pictures and enjoyed the video as well. I've been trying to figure out how to go around the thermal bypass valve to flush the system.
Do you remember the size of the clear tubing you connected to the metal line? Maybe I'll get away with only one trip to the hardware store.
Thanks!