4t60 not holding a gear?

[krut]

Hi. I have a jaspers rebuilt 440t4 / 4t60 transmission and it shifts fine unless I am at wide open throttle. - At that point it loses all gears until you take it to a full stop and then put it back in gear (if you're lucky -- you have to let it sit a while) - I am curious if this is an issue with the transmission or something that is fixable. Thanks in advance

[gpse3400]

I do not think that can be fixed easy. Sounds like something is sticking in the valve body, I would have it warrentied.