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Mine does the same thing especially with the cruise on .tries to slow you down no worries as long as it doesn't go past the red line. Would never shifted it up in neutral putting a lot of strain on your brakes going downhill get them things hot you are in trouble. Not saying there's something wrong with your transmission .Iet the engine whine but it sounds like it's going to come through the floor. Want to get a diesel with a jake brake then you still got the same trouble steep inclines are bad on anything.
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