10R80 Squeal / Whine When Shifting @ High RPM

[twotone5.0]

For some background, I have a 10R80 with almost 60k miles. For the last 10k miles I've owned the car, there have been no abnormal noises. I am aware of the quiet squeal that happens at idle and DI noises, but the noise I've developed over the last 3k miles or so is concerning to say the least.

The noise is about as loud as my cat-back exhaust, and sounds like a high pitched whine or squeal, almost like a supercharger whine in volume and tone. It happens pretty consistently once the car warms up and you step on it, particularly in Sport mode where shift points are more aggressive. I can also reproduce the noise by shifting with the paddles at high RPM, only in lower gears like 1-4. I've noticed it happens when the car shifts by itself in drive as well.

Gears 5-10 and gentle driving will not create the noise. The noise also doesn't happen for extended periods of time, only a quick loud squeak when the car shifts for 1 second and back to normal until it shifts again.

The car is stock aside from a Lund tune and exhaust. Tried replacing wheel bearings, they were not the source of the squeak. A buddy said it could be the axles but they aren't sure. Tuner said everything looks good on their end and it's likely a mechanical issue.

I noticed that the E85 tune produced the noise much more easily than the 91 tune I was given. Could this be due to the increased torque on E85?

Also, the car is not throwing any trans codes, and there are no pending DTC codes at all for that matter.

Wondering if anyone has experienced an issue like this / what the solution was if any. Or if anyone has any ideas as to what parts I could try and troubleshoot next. May just need to take it in to the dealer. Have an appointment in 9 days, just wanted to see if you guys knew about this issue.

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[andrewtac]

For some background, I have a 10R80 with almost 60k miles. For the last 10k miles I've owned the car, there have been no abnormal noises. I am aware of the quiet squeal that happens at idle and DI noises, but the noise I've developed over the last 3k miles or so is concerning to say the least.

The noise is about as loud as my cat-back exhaust, and sounds like a high pitched whine or squeal, almost like a supercharger whine in volume and tone. It happens pretty consistently once the car warms up and you step on it, particularly in Sport mode where shift points are more aggressive. I can also reproduce the noise by shifting with the paddles at high RPM, only in lower gears like 1-4. I've noticed it happens when the car shifts by itself in drive as well.

Gears 5-10 and gentle driving will not create the noise. The noise also doesn't happen for extended periods of time, only a quick loud squeak when the car shifts for 1 second and back to normal until it shifts again.

The car is stock aside from a Lund tune and exhaust. Tried replacing wheel bearings, they were not the source of the squeak. A buddy said it could be the axles but they aren't sure. Tuner said everything looks good on their end and it's likely a mechanical issue.

I noticed that the E85 tune produced the noise much more easily than the 91 tune I was given. Could this be due to the increased torque on E85?

Also, the car is not throwing any trans codes, and there are no pending DTC codes at all for that matter.

Wondering if anyone has experienced an issue like this / what the solution was if any. Or if anyone has any ideas as to what parts I could try and troubleshoot next. May just need to take it in to the dealer. Have an appointment in 9 days, just wanted to see if you guys knew about this issue.

So only at high rpm in 1-4, probably trans. If it was rear-end it would probably be in other gears too and most of the time. If under warranty I'd take it to them. I was looking for a spare trans and I think they list for around $2500 from Ford.

Maybe also look for something rubbing under the car, like e brake cable. Or a ripped diff bushing. Hard driving will probably have the most displacement in the drivetrain. Could be something rubbing during the shift and load/unload of the divetrain.