Squeal after up shift

[Jono.ful]

My 2012 SR5 with 240,000ish kms has been making a short but noticeable squeal immediately after up shifting. It was more often in the lower gears, but it's now happening between most up shifts, especially once the truck is warm. The transmission fluid has been changed at the Toyota recommended intervals, but that didn't seem to make a difference.

I'm not getting any codes yet, but I'm thinking I may need to replace the shift solenoids. Has anyone experienced anything similar?

 

[jp.vegas]

When's the last time you checked/replaced your serpentine belt?

 

[Bmnorm2]

When's the last time you checked/replaced your serpentine belt?

This. The most common cause of "squealing" is serpentine belt and/or pulleys.

 

[Jono.ful]

When's the last time you checked/replaced your serpentine belt?

This needs to be done too, but the noise is most definitely coming from the transmission neighbourhood.

It's really more like a chirp right after up shifting than a pulley whine.

 

[Jono.ful]

Just ordered a new v-belt, and I'll report back

 

[jp.vegas]

This needs to be done too, but the noise is most definitely coming from the transmission neighbourhood.

It's really more like a chirp right after up shifting than a pulley whine.

I'm going to say that it's highly unlikely you're going to hear any noise that's internal to the transmission with the exception of it being a pile of molten metal inside.

It's *possible* that you have a bad u joint that's making noise but my first, and easiest guess, would be the serpentine belt or perhaps one of the idler pulleys, as they're subject to a light shock load when the vehicle shifts gears and the engine RPM changes.