I believe that is where the problem lies. Both thrust washers are the 4 tang standard type and both are .060 thick. It can't be the one on the rear of the planetary because the snap ring holding the planetary is flush. If I remove the front washer (front of the planetary)I get the free play back, but the sun gear shell will be riding on the planetary without a washer. Something is different about the 4 pinion truck planetary, but I don't have a manual or any information on the difference.