4l80e valve body rebuild

3rd burned up for the previous owner of my 02 gmc 1500hd and i read that the sonnax sure cure valve body parts can prevent that from happening again so i got the drift and guide kit used off ebay and need to get my valve body fixed up, but i can't find youtubes or write-ups on how to do this part so if anybody has any refrences for clearer instructions, im not even 100% certain which bore the afl is.


here's all my parts pulled out and laid on top of their respective holes, i think. i need to find a pre 04 4l80e valve body diagram to make sure i didn't mix anything up. i will post replies with more pictures and information

here's me holding a 4l80e afl drift in front of what i think is the afl hole, which instructions say to run the drill bit first and then the drift, and if that's done proper and cleaned the replacement is that solid silver cylinder on the right? previous sonnax toolkit owner welded a driver onto a 7/16" drill bit, is that the one that is run in the afl hole first? Thanks for your guys' time and help, i need to find a write up on how to install the sure cure kit.

lastly, the rod im pointing at was the first that got the roll pin out, and when that pin came out, the spring shot the rod right out of the bore and I didn't notice which way it was oriented when in the valve body. it's almost mirror image, with the top being a longer gap that i'm pointing at. if i had to guess i'd say the long gap would go to the outside of the valve body but i have no idea I could have it upside down orientation right now. thanks again for everyones time!

@NickTransmissions is the guy to call for help here ...

blackbeard_lives said:

3rd burned up for the previous owner of my 02 gmc 1500hd and i read that the sonnax sure cure valve body parts can prevent that from happening again so i got the drift and guide kit used off ebay and need to get my valve body fixed up, but i can't find youtubes or write-ups on how to do this part so if anybody has any refrences for clearer instructions, im not even 100% certain which bore the afl is.

Click to expand...

Here you go - give this a watch, will cover everything from start to finish for 4L80E VB overhauls and likely answer all of your questions:

o shoot i shoulda looked more closely at nicks' 4l80e playlist, it's in there i just missed it, this should help a ton thanks!

NickTransmissions said:

Here you go - give this a watch, will cover everything from start to finish for 4L80E VB overhauls and likely answer all of your questions:

Click to expand...

running some parts thru the washer tonight and my reverse check ball disappeared. i have the new sonnax reverse pistons but i don't think there's a check ball in that kit. was i supposed to have to reuse the old ball? i noticed in some transgo instructions it says to leave out that ball but that's a different kit. i am dual feeding internally, direct no middle seal on the 2 piston halves, case plugged and pump drilled. guess i'm hoping the junkyard has a 4l80 and not just 4l60 trucks, so i can pull a tiny ball, darn it.

blackbeard_lives said:

running some parts thru the washer tonight and my reverse check ball disappeared. i have the new sonnax reverse pistons but i don't think there's a check ball in that kit. was i supposed to have to reuse the old ball? i noticed in some transgo instructions it says to leave out that ball but that's a different kit. i am dual feeding internally, direct no middle seal on the 2 piston halves, case plugged and pump drilled. guess i'm hoping the junkyard has a 4l80 and not just 4l60 trucks, so i can pull a tiny ball, darn it.

Click to expand...

Some of the overhaul kits come with a new set of check balls...Otherwise you can go grab one from your local hard parts supplier, probably for free or just leave it out, assuming you're talking about the reverse check ball at the rear of the case. If you're talking about one of the two 5/16" check balls in the valve body, you have to have both of them installed. Check w/hard parts suppliers, they should have some or even a good-used valve body you can harvest without having to spend time at the junk yard...

NickTransmissions said:

Some of the overhaul kits come with a new set of check balls...Otherwise you can go grab one from your local hard parts supplier, probably for free or just leave it out, assuming you're talking about the reverse check ball at the rear of the case. If you're talking about one of the two 5/16" check balls in the valve body, you have to have both of them installed. Check w/hard parts suppliers, they should have some or even a good-used valve body you can harvest without having to spend time at the junk yard...

Click to expand...

yeah i've got the sure cure kit with the torlon balls, but those are smaller than the end plug ball that went missing. I only ever had 1 ball come out of my valve body, was i supposed to find two? if i buy a steel ball for a ball bearing from amazon, is it 5/16" or 3/8"? or metric?

NickTransmissions said:

Some of the overhaul kits come with a new set of check balls...Otherwise you can go grab one from your local hard parts supplier, probably for free or just leave it out, assuming you're talking about the reverse check ball at the rear of the case. If you're talking about one of the two 5/16" check balls in the valve body, you have to have both of them installed. Check w/hard parts suppliers, they should have some or even a good-used valve body you can harvest without having to spend time at the junk yard...

Click to expand...

never mind, found the check ball on the ground under the washing machine ha.