Disconnect kickdown switch and see if that fixes issue....although I think its probably a different issue.

Start with new filter and fluid.

Any history? 300k on a 722.3 is getting towards the end if it hasn't been cared for meticulously...

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k