u/Broad_Foot_4380

2000 4.8l 4x4 w/ towing package
I have the 4L60e. With 300,000+ miles on the truck. Maybe 150,000 on the trans.

Oh Reddit-verse what should I do?

Just upgrade to 4L65 or 80? (If possible?)

Orrrrrrr re-build it much beefier?

If rebuilding, what kit should I use? I’ve found a “Stage-2” rebuild kit but don’t know enough about transmissions to know what that means.
I’m pretty handy with a wrench so I may tackle it myself over a weekend.

I like speed and get-up-and-go. But I like to tow things too.

My 3-4 are pretty much burnt out. Overdrive is very weak. 1-2 are solid, though. Common problem I know. But maybe upgrade the torque converter as well? Is that a thing?

Also, I’m off work for the rest of the weekend and are 7 PBRs deep and dreaming. So forgive the wordiness and ignorant questions.

GOBBLESS!

2000 GMC Sierra 4.8l 4L60E trans was slipping. It wasn’t wanting to go into overdrive and would occasionally bounce in and out of OD once it finally engaged.
Well, I took a 20 hour road trip (10 hours each way) and now the slip seems to be gone AND I feel as if I have better response time.

What happened?
Is this a sign of something really bad?