2020 LT Trail Boss 6.2 10 Speed whining when accelerating.

[Brian21477]

Have a 2020 LT Trail Boss 6.2 10 Speed that makes whistling/whining noise when accelerating around 20-35 mph then drones out.  Has 2500 miles on it.  Been at the dealer twice now. First time they replaced the stub shaft, didn’t fix it. Second time replaced a bearing near the transmission pump, didn’t fix it.  The dealership is scratching their heads on this one! I can’t tell if it’s noticeable from outside the truck but i sure hear it from the cabin while accelerating.  Any idea what this whining sound could be?

Edited December 3, 2020 by Brian21477

[Doug_Scott]

See if the dealer has a new vehicle on the lot that you can take for a test drive and see if that noise is in that truck as well.  My first thought would be that with so many gears being produced inside the case via planetary gear sets it may be simple something that needs to be "worn in".  Make sure it is documented fully by the dealer so that there is prior notice of it having a gear noise in the transmission in the notes for your trucks VIN.  If the truck has a manual shift switch, try manually changing gears while the noise is happening, have to think a 10 speed will not be in 10th gear at that speed.  If it changes/goes away as soon as it shifts either up or down (in other words it only whines in 4th gear) the dealer will have something to go on.  In every gear there is a unique pattern to what clutch pack/band is applied that routes power through the planetary gear sets.  If just one of those gear sets has some minor alignment issue it will make a noise.  There is a shop on Youtube called Precision Transmission that has videos of him taking transmissions apart, watch a few of those to get an idea of how the power is passed through the various gears.  Isn't this the same transmission Ford is using in there trucks?  Maybe take one of those for a test drive to see if they also make the same noise.

 

It would not surprise me if this is simply a meshing issue that needs to be run in.  

[tlaw91]

Sounds like the valve body
The pump is inside the valve body
Sounds like the issue I recently fixed on a 10 speed
Concern was noisy transmission
I threw a valve body at it
It fixed it
Happy days!


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