Torque Converter drain down, Trans guys, opinions?

[sled_dog]

I have a 1997 C2500 with a 4l80e. Lately if I let the truck sit for a few days(as I often do since it is for sale and I drive my Saturn), when I go to pull out of my spot at the house, I throw it in reverse and the reverse shift is pretty delayed. But there is no SLAM like there is a real delay in shifting. Just like it doesn't have any torque in reverse for the first few seconds. To me it seems like my torque converter is draining down when sitting and needs to refill and build pressure. It was rebuilt shortly before I got the truck (rebuilt 40k ago). I don't know 4l80es internally but I'm betting there is an anti-drainback valve in the pump thats letting it drain down. One of the Ford techs at work said F150s had a TSB out for the same problem a bit ago and that a decent fix was a Lucas transmission additive. Said it provides a harder shift too. not a fan of that idea really, any thoughts? I really want to avoid pulling my transmission and attacking that pump, but I likely will have to to really fix this. if it comes to that, I'd much rather not put an automatic back in....

 

[sled_dog]

come one, someone has had to have had experience with a problem like this. GM techs? Trans techs? I know there are some of both here.

 

[jarheadk5]

Doesn't really help you much, but the 700R4 in my C10 diesel-donor did this the last couple times it moved under it's own power. It was also a couple quarts low on fluid...

Stupid question - didya check the fluid level?

 

[sled_dog]

yeah I checked it a couple times thinking that was the problem. I just did a trans service and lets just say the fitting sprung a little leak on me. But it only took a quart or two after the service was done so I was paranoid. Maybe I'll check it cold, don't think I've done that yet.