what causes shudder in the 2008 camry transmission between 20-50 mph? on 2008 Toyota Camry

when the tranny shudders it feels like driving over a very aggressive rumble strip. It usually will not do it when the trans. is cold or within the first few miles of travel. it never does it over 50 and I don't seem to notice it below 20-25 mph.

by in Norridgewock, ME on December 25, 2013
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1 answer 1 comment
ANSWER by , December 25, 2013
How many miles on it and has the trans fluid ever been serviced (Toyota Factory fluid)? Could be torque converter judder , possibly would improve with fresh fluid.
COMMENT by , December 31, 2013
it has 214,000 miles on it but runs like new other than this shudder. I am not aware that the fluid has ever been changed. I bought a filter and gasket kit and will change the fluid to see if that makes a difference. Thank you very much for your info. All that the Toyota garage would give me for info was to replace the tranny.