After complete transmission replacement, moderate whining noise while towing. Thoughts?

[InSearchOfLight]

Just finished a 2,400-mile RV trip towing a travel trailer (3,000 lbs dry, likely 4,000+ loaded) with a truck bed full of camping gear and two fat-tire e-bikes on a rack above the bed. My wife and I were in the truck.

The transmission was replaced at about 16,000 miles (the truck currently has 19K), and has performed well until this trip, when I experienced two issues:

1. First Incident: I noticed a whining sound from the transmission on the freeway, especially during shifts. Unfortunately, I didn’t document specifics.
2. Second Incident: While cruising at 70 MPH, the transmission began whining, particularly between 6th and 7th gears, and there was a moderately hard shift—rougher than usual since the replacement.

Conditions during the second incident:

• Outside temp: 67°F
• Transmission temp: 240°F (via OBDLink MX+)
• Engine temp: 197°F (via OBDLink MX+)
• Elevation: 2,400 ft
• Terrain: Incline (~4% estimate)
• Weather: Gusty winds

I was surprised by the significant difference between engine and transmission temps, as I’ve never seen the transmission run this hot. I suspect the high temperature might relate to the whining—possibly an issue with the torque converter?

I realize towing at 70 MPH may be pushing it, but the engine didn’t seem to struggle. Afterward, I adjusted by locking out gears 9 and 10, slowing down, and downshifting to keep turbo boost under control. From that point, I didn't see the transmission temp go above 220°F.

Does this seem normal, or could the 240°F transmission temp and whining point to another transmission issue? I had the 15K service done a few days before the trip.

Thanks in advance for any input.

Sponsored

 

[Porpoise Hork]

Towing is absolute hell on the overdrive gears. You should always run in Tow Mode and lock out 9th and 10th when pulling that extra weight. If you were not in tow mode for this then it's a safe bet the adaptive tables are likely all jacked up now and is the reason for odd behavior. I'd definitely consider resetting the adaptive tables with Forscan and letting the system re-learn with a smattering of normal and sport mode driving around town for a couple hundred miles.

 

[InSearchOfLight]

Thanks for replying. I was in tow mode 100% of the time but only started manually locking out 9 and 10 after the second incident. Sometimes, I even locked out 8 on inclines.

Also, do you know if overdrive on the 10R80 is 8,9 & 10, or just 9 & 10?

 

[Porpoise Hork]

Fairly certain 8-10 are overdrive gears given the ratios fall below 1.0 : 1 after 7th. With 8th 0.85 : 1, 9th 0.68 : 1 , and 10th being 0.63 : 1. The PB 10R80 MHT variant should be the same.

 

[InSearchOfLight]

OK cool, thank you.

 

[DT444T]

https://www.f150gen14.com/forum/threads/high-trans-temps.21793/post-420171

I got a new transmission and hit 241° without a trailer on within the first 50 miles of driving. Hit 251° outside ABQ and was leaking fluid.

There is a thermostat in the transmission coolant lines that open when the trans is cold to help it warm up, and closes near op temp. It will also open when the trans gets hot. Mine was stuck at 1/4 open.

Honestly, it's a bad setup.

 

[FaaWrenchBndr]

Thanks for replying. I was in tow mode 100% of the time but only started manually locking out 9 and 10 after the second incident. Sometimes, I even locked out 8 on inclines.

Also, do you know if overdrive on the 10R80 is 8,9 & 10, or just 9 & 10?

I would get it into a shop. The noise is fairly indicative of transmission damage. Towing at 70 mile an hour, with wind,overdrive is never a good idea.

8-10 are all overdrive gears.

The noise is your transmission screaming at you telling you it’s got an issue. I would suspect you’re very far down the path to your next transmission.

 

[Porpoise Hork]

I would get it into a shop.

"No shit there I was just driving along (towing at 70mph "accidentally" omitted) and it suddenly started making this whining noise during shifts and after that it randomly began shifting rough too..." @InSearchOfLight said to the Ford service advisor.

 

[Vater]

Thanks for replying. I was in tow mode 100% of the time but only started manually locking out 9 and 10 after the second incident. Sometimes, I even locked out 8 on inclines.

Also, do you know if overdrive on the 10R80 is 8,9 & 10, or just 9 & 10?

Yes. All 3 gears are overdrive gears. Lock them all out and 7th should be close to 1:1

 

[dochawk]

I'm thinking that the whine could be coming from the should of the four accountant that grudgingly approved the transmission replacement!

?

 

[InSearchOfLight]

Yes. All 3 gears are overdrive gears. Lock them all out and 7th should be close to 1:1

Thank you.

 

[InSearchOfLight]

https://www.f150gen14.com/forum/threads/high-trans-temps.21793/post-420171

I got a new transmission and hit 241° without a trailer on within the first 50 miles of driving. Hit 251° outside ABQ and was leaking fluid.

There is a thermostat in the transmission coolant lines that open when the trans is cold to help it warm up, and closes near op temp. It will also open when the trans gets hot. Mine was stuck at 1/4 open.

Honestly, it's a bad setup.

Thanks for the info, I will keep my eye on the temps.

 

[InSearchOfLight]

I would get it into a shop. The noise is fairly indicative of transmission damage. Towing at 70 mile an hour, with wind,overdrive is never a good idea.

8-10 are all overdrive gears.

The noise is your transmission screaming at you telling you it’s got an issue. I would suspect you’re very far down the path to your next transmission.

Thank you.

 

[FaaWrenchBndr]

Thank you.

truly sucks to hear you’re having problems again. Let us know what you find out if you would please.

 

[redduke916]

My transmission makes a high whining sound above 3,000 rpm when towing. Transmission was “serviced” for the low gear jerking. It was slightly better but returned. It has 53,000 miles, half pulling a 8,000 pound trailer. Now it leaks, I overheated once and it’s back in the shop for the leak and service. Any comments appreciated as it’s currently back in the shop.

Sponsored