4l80e rebuild
 

Okay, here are some of the parts I am looking into buying for the rebuild:

Thrust washers
Bearings
Gaskets
O-rings
Pistons (bonded)
Clutches, Steels Borg Warner High Energy
36 or 34 Element Sprag
Front & Rear Band

The trans looked very good in comparison to my old 4l80.
Do I just buy the 34 element sprag by itself or do i need to have the drum machined? what other components should I throw in there to hold up to 600-700rwhp for future mods.

I am in the process of rebuilding mine now, i bought all new sprags...

did you get the 16, 34 or 36 element sprag? If you got the 34 0r 36 did you have to get the drum machined?

Huh, I just measured my a few clutches from one of my clutch packs from my old 2003 unit and my new clutches from the new kit and they are the same thickness. I'm now wondering why my transmission was slipping. Could it have been the torque converter this whole time? The trans was dirty as hell so I thought it was clutch material. maybe the debris in the torque converter contributed to the loss of power as stated on page 7 of the astg. Or maybe it was the tcc stuck on. IDK what it was. How does one know when the clutches are bad? They showed very minimal brazing

Are there hot spots on the steels?

As in discoloration right? If so there is very little.

If the clutches were slipping very much there will be blue, and brown spots on the steels.

with transmission's it could be a dozen different things. I would inspect everything carefully for cracks and breaks. Internal leaks and seal damage. VB valves sticking, ETC.

You got it torn down, so take your time and meticulously rebuild it. Make sure you replace all the Electronics in the VB.

Vince:

I saw a post you wrote on ls1tech, here it is:

"I have built plenty of these units using transtech overhaul kits. Normally I just use Borg Warner frictions and bands. I have found these to work just fine and really take some abuse. There are many things that go into a build to make a trans hold up and stay together.

Things like end play and clutch clearance are the main ones. Also I like to use a self regulating boost valve from Sonnax, Sonnax lock up valve for the valve body, wide TF8 direct clutch snap ring for the intermediate clutch in the 80, and modify the direct clutch circuit to dual feed the direct drum.

This can be done by leaving the second sealing ring from the top of the center support off, remove the center seal from the inside of the direct drum, and block the feed in the case with a parking pawl plug from a TH350. From there opening up the feed holes in the separator plate for 2nd, 3rd and 4th seem to help with shift feel."

I am thinking about doing this but I am not completely following you on how to do this. what is the second sealing ring of the center support? I am looking at figure 65 from the astg manual but I am unsure what you are referring to. Also, what is the center seal from the inside of the direct drum? Can you explain more in detail? Is this mod necessary for around 500rwtq/hp? I may go up to 700 if i can rob a bank.

Keep in mind I am using a transgo hd2 kit and the trans is a 2007. While I am doing the rebuild should I also use all of the hd2 springs for the direct clutch? I read a thread on crankshaftcoalition.com to only utilize half of the springs from the hd2 kit and half of the stock springs.

On Another note.............................................. ..

With the steels:

There are the tabs that look to be machined down on opposite sides and in the 4th clutch housing, there is a groove in one of the tabs. is there a special sequence that these steels need to go or can the steels be stacked any way? It seems that the groove in the 4th clutch might be there as a fluid passage?

Rear end play:

I am stuck at the center support and cannot install anything else in the trans because rear end play is at .033". I read on Sonnax's website that I can either attain the desired end play by adding a thicker selective washer or to add the Sonnax spacers in between the sun gear and the rear internal gear. With the Sonnax spacers (.10") they say you can only shim so much with this method before it loads the center support. To achieve my goal of getting into the rear end play of .005"-.025" which would be the best solution for me? If I put 2 Sonnax spacers in I should achieve .013" end play.

Anybody other builder's who have an opinion feel free to chime in.

Thanks a bunch!!!

To Dual feed, here is what you need todo:

1. Center support, leave off the red ring below
Attachment 144833

2. Center seal on direct leave off the red below
Attachment 144834

3. Block the feed in the case, plug the red below
Attachment 144835


I hope that helps.