Well I'm new to the transmission game, and I have a stock 4L80E Trans w/ 68k I just bought that I want to rebuild and possibly modify. I was just curious what some of you would do; if you had a stock trans to mess with before it got installed.
Basically I will be rebuilding it and wanted to know some of the quality brands out there for rebuilding kits, etc. I will need to change the output shaft from a 2wd to a 4wd I want this thing to be perfect before it goes in. It will be mounted to a 6.0 w/ a supercharger so it will have some decent power going through it.
Thanks

 

If your new to building them and want to run a F/I 6.0, I'd recommend selling it and buying one from somebody whose been building them for years. I've seen reputable shops build some and claim it's "bullet proof". Few weeks later, it's trash.

For the most part, You shouldn't really need to do anything to it tho. Shift kit, servos and trans cooler. Those 80e's are pretty damn stout as they are.

 

Just depends on how much power your making. I would put a 34 element intermediate sprag in it for sure. Also a transo shift kit and a large cooler and you should be fine.

 

A stock 80e will handle alot of power. With a 60e the builder needs to know all the tricks to make it hold up to alot of power . This is not the case with the 80e

 

34 element FOR SURE, as well as the shift kit.

What year is the trans?

 

It's an '02 with 68k on it.

 

Did they all get the 34 element sprag starting in 02? My 4l80 has taken a beating with a shift kit only, that's all I would recommend if you already have the sprag and a cooler.

 

4L80E's aren't bomb proof thats for sure, nothing is. With 68,000 miles if the transmission physically works fine I would do nothing more then a shift kit and keep it cool. I don't see any reason in completely tearing down a known good working transmission for a few upgrades that can always be done down the road during a rebuild or freshen up. My 4L80E has around 135k miles on it and what I could see looked great so I put a shift kit in it and ran it. Put a few thousand miles on it and so far it handles my small block like its nothing.

 

This is a 2wd trans and I need it to work for a 4wd. From what I've learned I need to completely gut it to replace the output shaft. I got such a deal on it I could pass it up. $1150 for a 6.0 and 4l80e with 68k from a 2500HD, and local, I couldn't resist!

 

A complete rebuild vs gutting the trans to replace the output shaft are too very different jobs...
Most of the clutch assy and planet groups will stay together, the only clutch you will deal with is overdrive. Yes you will remove all the parts in the trans but that can be done in 15 minutes, take each clutch/planet assy apart, replacing lip seals, clutch plates and re shimming will take much longer.... If you have the tools, the money and the time then there would be no reason not to completely rebuild it. BUT if this is you first go at trans rebuilding, I would recommend to just replace the output shaft... You can always rebuild it later....