04 Silverado, 3/4 80e, 4wd . . . all stock. 33" tires, and a trans cooler, 120K miles.

I was crossing an intersection, and mashed it to 1/2 throttle, and it slipped, then grabbed. Meaning from a dead stop, let off the brakes, rolled a little, hit the gas, went no where, RPMs went to 4K, hung for a sec, and then grabbed.

Motor was up to temp, but the trans was still pretty cold. I went maybe 2-3 miles from the house when it happened. Drove the rest of the day with no issues.

Changing the trans fluid right now, but it's pretty clear. I'm the 3rd owner. Father-in-law was the 2nd, and then an older lady was the original. I've been pulling a 4K lbs boat with no issues for a while, and this was the first time.

So what is it? . . . Doubt that it's just the light freeze that we had last night.

 

Bring em up to temp first, My 80 DOES NOT like the cool temps. Once it is up to temp everything is fine. Mine that is.

 

I remember dealing with an issue where the trans hung in 2nd gear at stops. Then all at once, downshifted into first, clunked, and took off like normal. Every customer described it as 'slipping, then going'. I used to see this pretty regularly at the dealer.

 

ahh well it was around 28-30 when I left
really . . . any fix for it ? . . .

a small cam and shift kit are in the works . . . that'll be the real test

 

My 80E is bad about hanging one gear above what it should while coasting or stopping when cold too, once its up to temp life is good

 

We had a Tech 2 re-flash from GM for the fix. On those trucks that the re-flash did not correct, either got a shift solenoid(if they had a code stored) or a valve body. Every truck did get fixed with one of these 3 repairs.

The most common occurrence was with a customer doing a 'California stop'.

 

With a neutral condition the trans is on it's way out or was low on fluid.

 

well it wasn't low . . . so would that be the forward clutches ?