2020 Plat Max Transmission Normal Temps

[Dice Roll]

Your new thermostat is RT1258 with 180F? On any day with ambient temp above 60F, my tranny temp is from 200F to 215F after 30 minutes driving with the factory 195F thermostat.

Paperwork shows hl3z 8575 and online stuff shows it’s the rt1252. The dealer was coy about what part they’d use and didn’t want to do the job anyway. I held my breath. All the was said was “we use the latest and greatest parts.” Just never know with these guys.

 

[zak99b5]

I put in the 180° tstat myself. Took less than an hour, and the gallon of premixed coolant I bought at the dealer was enough to replace what was lost. My original (brass collar) tstat was sticking, causing temp spikes to over 235° on the highway, loaded but not towing. Temps are now normal and stable.

 

[Hellwig]

Paperwork shows hl3z 8575 and online stuff shows it’s the rt1252. The dealer was coy about what part they’d use and didn’t want to do the job anyway. I held my breath. All the was said was “we use the latest and greatest parts.” Just never know with these guys.

RT1252 is the factory thermostat for 2022 model year and afterwards. The spec is 195F. It's amazing that you can achieve 160F-170F with it. My vehicle has the same one but the tranny temp fluctuates between 190 to 210 if not towing. If I tow, it would be above 210F and sometimes a little over 220F.

 

[Hellwig]

I put in the 180° tstat myself. Took less than an hour, and the gallon of premixed coolant I bought at the dealer was enough to replace what was lost. My original (brass collar) tstat was sticking, causing temp spikes to over 235° on the highway, loaded but not towing. Temps are now normal and stable.

Did you have to purge the cooling system to get the air bubbles out? Or there were no air bubbles after all when you replaced it?

 

[Dice Roll]

RT1252 is the factory thermostat for 2022 model year and afterwards. The spec is 195F. It's amazing that you can achieve 160F-170F with it. My vehicle has the same one but the tranny temp fluctuates between 190 to 210 if not towing. If I tow, it would be above 210F and sometimes a little over 220F.

If it’s not the 180 it makes me wonder if they put the wrong part in or put the wrong part on the paperwork. Should’ve been fully warm today and temps were about 175. Always over 200 since new until this.

 

[Hellwig]

If it’s not the 180 it makes me wonder if they put the wrong part in or put the wrong part on the paperwork. Should’ve been fully warm today and temps were about 175. Always over 200 since new until this.

Sounds like an aftermarket 170F thermostat.

 

[zak99b5]

Did you have to purge the cooling system to get the air bubbles out? Or there were no air bubbles after all when you replaced it?

I just filled it from the degas bottle and squeezed the hoses until it wouldn’t take any more. Started it up and let it get to op temp. It sucked a bit more in from the degas bottle, and I then topped it up again. Been fine ever since.

 

[TravisExpy]

I am wondering if others have experienced rising transmission temperatures in the 2020 Plat Max model line. We have about 75k miles. Last week, we took a family of 5 road trip to the midwest for a day's drive and noticed the transmission hitting 255 degrees. Very surprised. This is a first and I wondered if this is normal.

Thanks in advance! -Phil

I just got mine back after 3weeks in the shop today for the same thing. Only 47k miles on it and they just replaced the transmission for the second time. I didn’t own it the first time it was replaced but high temps is why they replaced it this time. Ford tells them to replace the valve body sleeve first and then rebuild the transmission if that doesn’t fix the problem. Our service advisor wasn’t real optimistic that this fix would actually work. It was fine this evening but I haven’t driven much and we haven’t tried towing with it.

 

[Dice Roll]

I did the first serious drive since the new stat went in. After thirty minutes, trans was at 165, before it would be 180-190. After a full hour it was 180. In about 200 miles today, it never went over 192. That was after repeated blasts to get around truckers hanging in the left lane on hills. Temps would back off some when returning to a steady cruise.

Before the new stat and flush, it was 203-205 on a regular basis when not towing. I’d see 212-215 with the rv.

I’m starting the think my stat didn’t fully open since new. The only time I saw anything erratic was about 4-6 weeks ago it had a wonky warm up when the gauge went back and forth a bunch to start the day, like it would stick open and closed and the trans hit 210-212 with no trailer on a cold day, upper 20s-30s.

 

[Dice Roll]

I hadn’t noticed the tech turned off the ac when he did the service. First time it mattered was on the trip over the weekend. With it on, it stays about 187 and sometimes 192. Still way better than with the factory stat.