TC not unlocking with foot off the gas pedal

[rotohead]

I have a lockup switch installed for a number of years now but lately my TC is staying locked up when I get off the gas and the lockup switch is off. What could cause this? If I apply the brakes hard enough it will unlock and RPM to idle. Any ideas from anyone?

 

[DavidC]

Mine has been modified for a long time and does not unlock until a certain speed occurs. I really do not remember how it was when stock.
I would think it would still stay locked until a certain speed also.

Dave

 

[Tractorat]

Auto, completely stock. If Im pulling up a really steep hill and the truck slows down, I cannot get it to easily get out of lockup. I let it go too long one time, and it did release. But with a rather violent "pop". The only way I can get it to let go is to drop the gear shift into 2nd.

 

[rotohead]

I thought proper TC should be at a steady speed (say 65mph) and TC locked up and when you let off the accelerator engine rpm should go to idle (750 rpm or so). Mod or stock that's the way mine has always behaved until recently. Then if you don't let speed bleed off to much the minute you apply accelerator again the TC would lockup immediately.

 

[DavidC]

Mine stays locked until under 45 in Drive, 18 (the modified part) when in 2nd. If it locked and unlocked everytime the pedal was moved I do not think it would last very long.

Dave

 

[rotohead]

...If it locked and unlocked everytime the pedal was moved I do not think it would last very long.

Dave

It only should unlock when at idle, not just when it's moved.