Recent D/A owner.

After driving at higher speeds and especially on the highway, when I brake or let off the pedal, it sounds like the transmission gives off a high pitch sound, kinda like it is racing a little. Is it the Allison trying to slow down the truck? Do not have the tow/haul on.

Would appreciate any comments to see if this is normal.

Thanks!Edited by: dchilders

I would say that it is completely normal. Mine does that when I let off the throttle. Not quite as much as when the tow haul is engaged but it is noticeable.