4l80 problems

[AnthonyS1984]

1997 K3500, if it sets for a couple of days when I start it and put it in drive it won’t do anything. If I put it in reverse and than back in drive it will take off.

 

[454cid]

At a prior job, we had a work van that would do that. We took it to a transmission shop and they fixed it....Unfortunately, I don't recall exactly what the problem was. I think they dropped the valve body and replaced a seal/o-ring or something. One of the things that can cause it, is going from reverse to drive without coming to a stop.... the man that drove the van regularly, said one of the employees that was no longer with the company had done that a lot.

 

[df2x4]

My red truck does a similar thing after I 4L80E swapped it. (Junkyard 4L80E that came out of a 300K+ mile truck) If it sits for a week or more and I go start it up, it won't move if you put it in gear immediately. I usually go to reverse first as I pull it into my garage. I asked my mechanic about this and he said that his best guess was the torque converter draining back into the case when it sits for extended periods of time. When you first start it up, put it in neutral for 3-5 seconds and then go to whichever gear you want. This is what he told me to try and it has worked 100% of the time.

I'm sure it's some type of issue inside the trans, but I hate to bust it open for a rebuild when that's the only issue it's having.

 

[Supercharged111]

Both of my 4L80s drain back like that too. My driveway is on an incline so by the time I back out and get it in drive it's already pumping so I hardly ever notice it.

 

[1ton-o-fun]

Good info for this first time 4l80e owner!
I love this forum!