Bought the Excursion 5 years ago. Still love it! Haven’t had to fix anything in over 6 months (knocking on wood). I haven’t driven that much since October though. Who can these days with diesel prices around $5/gal?

 

The ones who burn vegetable oil can!

This beautiful X is getting a Vegistroke system in the next couple weeks.

 

Well the transmission lost reverse a few months ago. Finally got it replaced. Went with a transmission shop in Mineral Bluff, GA that @SkySkiJason recommended. He apparently builds a real nice transmission. Problem is I live 3+ hours away from there. When Bobby found that out he recommended I get a national rebuild brand, either Jasper or American Transmission for their nationwide warranty. He could only warranty his rebuild if I brought it to him. Made sense. He called both Jasper and American on speaker and got a quote. Bobby gave me that price on the transmission (no markup), only making money on the install. I went with the American Transmission with a 36mo/100,000mi warranty. It was supposed to be a 10 working day delivery and then another 3-5 days to install...so about Thanksgiving. Transmission showed up at his shop the next day and Bobby had it installed and test driven in less than a week. So far, so good!

 

Love the Ford Factory air filter kit, the Donaldson AIS.


Factory Kit Donaldson AIS

My truck has one. Works great.
Nate

 

A) I’ve got an AIS installed.

B) There’s a marketplace here on FTE to sell your vehicle. Other people’s threads isn’t the place for that.

 

Post edited. Marketplace will be used soon. Few more days.

 

My new transmission was running real hot since this spring. 205-225F without towing anything if I drove far enough and fast enough. With some suggestions from both Bobby at the transmission shop and @SkySkiJason I started some investigation. I started up my tablet for the first time in over a year and found that the transmission temperature the PCM reads is 10-20F higher than the probe my dash gage uses. So, that 225F+ is closer to 245F and very nearly in the danger zone. I pointed my IR thermometer at the inlet and outlet lines right where they go into the side of the transmission...virtually the same temp when at operating temperature (or much higher). So...something appeared plugged.

I assumed the transmission shop did a good job flushing the transmission portion of my radiator and my 6.0 cooler so wasn't going there until later if necessary. I changed out my Magnefine inline transmission filter. Just out of curiosity I cut it open to see if it was plugged. It was not...looked brand new even though I hadn't changed it out either before or after the new transmission install. An oversight on my part.

Next on my list was bypassing the Derale transmission thermostat. I put that off for darn near a month because I wasn't looking forward to it and then I got Covid and just didn't feel physically able to do it. Well, today I finally got around to it and used a lot of the words I learned in the Navy (ok, I knew those words in the Army, but you'd know I was a Sailor by my mastery of them). Man, I hate working on transmission stuff as everything gets so slippery with fluid and where I had the thermostat would be best accessed with tiny hands. I have no idea how I got it there in the first place. Instead of just bypassing I went with a total removal with no intention of ever installing it again, no matter the outcome. Even though @Mark Kovalsky likes having the transmission at a good operating temperature, I doubt I'll wear this one out...as long as I didn't damage it with the high heat. No burn smell in the fluid and its still new red in color.

After the thermostat-ectomy I went on a 110 mile shake-down cruise, with 80 of those miles on the interstate at 75mph. Temps maxed out at 191F on the dash gage and remained relatively constant over the last 25 interstate miles. Ambient air temp was 86F or so. This is as opposed to the gradual rise to 227F the last time I drove home from the Atlanta airport (about the same ambient temp). Back then the trans temp never stabilized...it just kept rising a degree every 4-5 miles or so. The 191F I got up to today is about 10-15F higher than my old transmission ran unloaded. Not sure what that's about, but I'm about 80% convinced the thermostat was stuck closed or partially closed. Even when operating properly, it is still supposed to only bypass 90% or so when "fully" closed. With the Derale out of there, I had about a 20F delta between the inlet and outlet lines using my IR thermometer.

Fingers crossed and Derale tossed.

 

Fingers crossedp

 

I never recommended installing a thermostat in a transmission. From what I've seen from other people who have done it, they are restrictive and cause the transmission to run hot.

And good luck with your reused coolers. It isn't possible to adequately flush a 6.0L cooler. It can't be done. You might want to install a filter downstream of that cooler to catch the particles that WILL eventually break loose. However the filter can also cause restriction...

 

Sorry @Mark Kovalsky my bad on mis-remembering the thermostat recommendation. Looks like I need a new radiator and 6.0 cooler.

 

Im gonna say your coolers are probably ok. The filters should have kept debris out of them and the flush machine the transmission shop uses is $7k or so and pulses hot fluid through coolers in both directions to ‘clean’ them. I struggle to believe there could be enough debris to cause blockage or reduce cooling ability.

Im hopeful that with the unnecessary restrictions removed from the system you’ll see stabilized temps. Just guessing here, but possibly a different kind of torque converter could produce higher temps than your OE converter? Not sure what they put in your ‘nationwide warranty’ transmission, but Bobby has been putting ‘heavy duty low stall “RV” converters’ in the builds they’ve done in house for me. I can’t say I notice a difference in how these trucks drive with that TC.

It may be possible that you factory bypass valve is not sealing correctly and fluid is not going to the coolers like it’s supposed to?? Not sure how to check that....

 

FLOW TEST the transmission cooling circuit.

If you get a gallon per minute (or a quart in 15 seconds) of FLOW, then the cooling circuit will return enough fluid to the 4R100 to meet operational needs.

If you don't, then one of the coolers might be restricted, and I would be inclined to only replace one transmission cooler at a time, and then retest for flow.

IF there was not any known transmission failure or smell of burnt clutch material, and IF a pan drop (save the fluid if fresh) reveals a fairly clean magnet, then I'd start with changing just the OTA cooler, as that is the least expensive between the two, as well as the most accessible between the two.

The OTA cooler is far more likely to get clogged up, based on its design and based on reported experience, and is least likely to get cleaned up with a flush.

After replacing the OTA cooler, conduct another FLOW test (all the testing reported in this thread has been temperature based, yet restriction is best tested by determining return FLOW). If the return flow out of the cooling circuit is at least one full quart per 15 seconds, then the OTA change was a success, and there probably isn't any need to incur the expense of changing out the radiator.

On the other hand, zooming back to step one, which was fluid inspection with a dropped pan.... if you saw a pan full of clutch slurry, then yes, change BOTH the OTW cooler in the radiator as well as the OTA cooler, because the high volume of debris makes it more likely that the OTW cooler may harbor enough debris to contaminate the new OTA cooler.

Alternatively, the OTW cooler can probably be flushed with success, because the passages inside of it are larger. Consider asking the shop to just hook up their flush machine to the OTW cooler in and out ports, and to the back and forth pulsing thing in that alone.

Don't bother having them flush the OTA cooler, as that should be replaced anyway. There is no need to disturb the debris in the old OTA cooler and redistribute it back into the cooling circuit.

One reason why I don't like flush machines is because I don't want someone else's lingering debris in my transmission, and I have no way to know how contaminated the flush machine is. I've never had a transmission, or transmission cooling system, flushed, for any vehicle, ever.

 

This should say one full gallon per minute.

I don't see how anything from another transmission could be transferred by a flush machine.

The output of the flush machine connects to the cooler inlet, and the return from the coolers goes to the return line. Flow is in one direction, with new fluid entering the cooler circuit and old fluid with debris going to the return on the machine. How would those intermix?

 

It took me a long time to find where I said "a full quart per minute", because the first sentence I said was a gallon per minute.

I almost gave up, but I finally found it somewhere in the middle of my fifth paragraph... and corrected it to match what I had meant and had already said in my first sentence. Thanks for catching it.

On the flush machine, there are different types. The term transmission "flush" has for decades been used synonymously with the use of transmission "fluid exchanging" machines that have an internal pump that is capable of reversing flow through the transmission. Any machine possessing its own pump and plumbing, with the capability of reversing flow, that is exposed to any given transmission, where a number of options exist for how the machine may be used, would seem to me to leave the pump inside the machine exposed to the fluid that the machine evacuates, or exchanges, in one direction or the other.

Ford, on the other hand, has transmission cooler flush machine, that is not used to evacuate or exchange fluid from the transmission, but is solely used for flushing the transmission coolers. That's a bit different, and I suspect that is what you are referring to, whereas I was referring to a machine that I have always been leery of... a transmission fluid exchanger that is often referred to as a flush machine.

As stated, I lack experience as a user of or customer of either machine, so my fears may be unfounded.

 

I've heard that myth, too. It isn't true.

How does the machine get around the giant check valve in the transmission, which we all call the pump? Unless they are turning the engine backwards while flushing the fluid is NOT reversing through the transmission. Fluid exchange machines can only flow fluid in the normal riirection of flow. Reversing flow is impossible.

That's the one that I wouldn't use. It CAN reverse flow, and with the changes to later model transmission coolers, I do not think these are at all effective. Starting about 20 years ago (I'm getting so old! I was thinking this was recent...) there are turbulators in the passages of the air to oil coolers. These are small tabs that disrupt the flow so that it is turbulent through the cooler. This makes the cooler more efficient because more of the ATF actually touches the inner surface of the cooler. WIthout these the flow near the inner surface would cool pretty well, but the majority of the flow would go right past this cooler fluid and not cool off a whole lot.