'53 Ultramatic, delayed TCC unlocking when warm

Posted by Ken D On 2017/11/1 10:24:41

I have a '53 Clipper with Ultramatic. The TCC appears to lock up at appropriate speeds, depending on throttle setting. The problem is that when the engine and transmission are thoroughly warmed up, the TCC does not disengage until the car is at a crawl. This causes the engine to lug on deceleration to a stop. When the transmission and engine are cold, the behavior is much better. I believe the tranny has Type F fluid in it.

I found a receipt from a previous, previous owner for a transmission rebuild only a few years ago, but it doesn't go into detail about what was done.

Does anybody have any ideas? I searched the archive but didn't run across anybody who had this specific problem. The TCC engagement seems grabby.. It is quite noticeable when it happens, though I wouldn't call it a jerk or a lurch.