transmission temp got to 300 degrees, is that hot enough to where it needs a rebuild/replace transmission?

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igokom10

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Short story: after having my valve body replaced ( along with fresh fluid, filter, tcm reprogram.) less than 100 miles later, was driving on highway and noticed it wouldn’t go into 10th gear after multiple tries, few Seconds after “powertrain malfunction” displayed. I pulled up transmission temp on the display it was around 280, by the time I pulled over safely it was 300 degrees. Was at 300 for a few seconds. Towed it back to the shop where I got the valve body replaced, serviced less than 100 miles go. Is 300 degrees, although for a brief second enough to cause enough damage to warrant a rebuild/replacement?

Long story: bought the car 2 months ago, with 84k, currently has 86k. Have the heavy duty tow package. Noticed some weird shifting from 3-5, sometimes would take 1-2 tries to get into 10 Gear, clunk/slight delay from P to D, Twice under very light throttle, tranny went from 3rd straight to 8th, rmps went super high, and car wouldn’t move. Pulled over, let it downshift to 1st and drove again no issues (besides what I listed above.) over all the shifts seemed bit clunky about 50% of the time, the other 50%, drove decent. Didn’t throw and codes. Around town driving temp was 215-220, I would hear the fan constantly trying to cool the unit down. so I finally decided to take it in to a transmission shop.
upon telling the tech my symptoms, he said 9/10 times it’s a valve body, didn’t even open it up, just said that’s what he would do. Took his word, he couldn’t source one (back ordered till April/may) I found one at a dealership in stock. Made the drive 2 hours away, picked it up and dropped it off for him to install. Day later he calls says he swapped over the new valve body but the 3-5 clunk is still there…said the oil was in great condition with no burning or shavings. He recommended I take it to a dealership see if they could diagnose that 3-5 clunk. I picked the car up and drove it home. It felt much better, shifting was more crisp and noticed it went into 10th gear all the time and occasional the 3-5 clunk was there but much much better than before. I was ok leaving it as is if dealership couldn’t diagnose it.
Day later I’m on the highway and notice it’s having a hard time going into 10. After a few attempts (3-4) the “power train malfunction” light came on, by the time I pulled over safely the transmission temp was 300, with ATF leaking from the bottom.
Towed it to his shop, thinking it was something they had done.
He calls me the next morning, the leaking oil was from the vent, and it came out due to the transmission heating up. He said he dropped the pan and again no shavings or any sign of anything catastrophic. Said the put fluid back in, drove it and it drove like before but still needs to figure out why it over heated.
He is dropping the transmission Tommorow and we’ll see what the inside looks like. I’m guessing if the temp got that high, a rebuild/swap is inevitable. Also from my research the CDF drum is a common issue. If that is fairly Would that cause the transmission to over heat?
Could they have made a mistake in installing the valve body that made it over heat?
I found a tranny from a 2018 f150 3.5 (floor/dial shift) few hours away with less than 20k miles for a good price ($2500)
Would that be a direct swap? From 2018 f150 to 2018 expedition.
I’m almost inclined and swapping out the whole thing, expecially because now it was overheated.

If you’ve read this far, you’re a champ and I’ll buy you a beer if you respond.
Thanks !!
 

SyndicateZ

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just a 2018 and tranny issues. I say get it to where it drives and will pass a trade in inspection and trade it in
 

SyndicateZ

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I just got the damn thing! Love everything about it, maybe I’m just wishful thinking it can get better. They can’t all be crap, can they?.
Haha i was kidding. The best you can do to get this resolved is dropping it off to the dealer and hope they fix/figure out the issue and fix. Is it under a extended warranty at all?
 

Soliyou

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Most probably it is the CDF drum. It seems they fail around that mileage. A complete transmission from Ford is $3500.

Unfortunately, even the new ones will have the same fate eventually since they didn’t change the design. The aftermarket has no solution either.
 
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igokom10

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Most probably it is the CDF drum. It seems they fail around that mileage. A complete transmission from Ford is $3500.

Unfortunately, even the new ones will have the same fate eventually since they didn’t change the design. The aftermarket has no solution either.
Would a bad cdf drum cause it to over heat?
Ford transmission are on back order till mid-end of April unfortunately. The used one I have has had the CDF drum already changed by the dealer at around 10k miles.
Any idea on cost to change out the CDF drum?
No warranty here. All out of pocket
 
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igokom10

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Haha i was kidding. The best you can do to get this resolved is dropping it off to the dealer and hope they fix/figure out the issue and fix. Is it under a extended warranty at all?
No warranty
I had the option to buy one from the dealership I got it from but i passed up. Said I have 30 days if I change my mind, didn’t think I needed it. I’m not at 50 days from day of purchase. Just my luck.
 

BMW2FORD

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Would a bad cdf drum cause it to over heat?
Ford transmission are on back order till mid-end of April unfortunately. The used one I have has had the CDF drum already changed by the dealer at around 10k miles.
Any idea on cost to change out the CDF drum?
No warranty here. All out of pocket
When the C D F bushing moved in my 2018 the temps did start to go up. It didn’t reach as high as yours and got to about 230. It also made a the noise you hear when hydraulics are not bled since when that bushing slips fluid pressure is not going to the correct C D F clutches. I’d have to look in the repair manual but possibly the fluid pressure could be checked to each of those clutches to see if it shows a pressure problem that would lead to that area. If you do have to change the C D F drum, it’s way in there so everything else has to be removed so a good time to see if heat damaged anything else. I’ll try to look at the repair manual and circle back.
 
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