Ok I'm looking to start rebuilding a 4l80e I picked up a little while ago. I haven't rebuilt one yet so I'm looking for any advice you guys have for me.

1. What parts do i need for a full rebuild
2. Any tips to consider while rebuilding?
3. Where to get parts?

Thanks for the help guys!

 

All depends on your goals (power, driveability, etc), budget, what the trans actually needs, and confidence in your rebuilding skills.

What year is the unit and how many miles on it? How did the fluid look?

 

I'll tell you this, I bought the ATSG manual, tore the trans down, removed all the guts from the inside, and as soon as I started the very first step of reassembly I realized I was in over my head. Boxed all the guts up and took it to a trans shop. and I'm very glad I did. They applauded me for wanting to try, lol.

It's very daunting in my opinion, so many internal pieces, so many clearances. I wish you luck if you attempt it, it wasn't for me.

 

I agree on the overwhelming part. But I didn't give up. It's been two months since I tore it down and it's not fully put back together yet, but I try to work on it a little bit every day. I've spent countless hours searching online for tips, pictures, guides, etc. Hopefully it works okay!

Definitely get the ATSG manual, however even it is missing steps and does not account for some differences in parts between years, which can leave you confused. Also download the following manual and start reading. Understanding how the trans works is the first step, and it will make it far easier to rebuild if you know what the purpose of each part is.

https://www.dropbox.com/s/h7ckb9edafc7cgd/4L80E.pdf

 

I have rebuilt a th400 before. It is a 98 4l80.

I am wanting to buil it for 700-800 hp. It is in my dd twin turbo silverado that I still pull trailers with. I haven't taken the pan off yet.