Re: 4L80E & TH400 Tech.
 

That is awesome. Thank you! Great to see all of clinebarger's hard work in this thread again.

Re: 4L80E & TH400 Tech.
 

Thanks, Works on my end! This calls for MORE TECH!!!!!





Intermediate Clutch Tech
As the 4L80E ages, I have noticed something interesting about the Intermediate Piston Return Spring assembly......It is VERY weak & bows up at the spring perches, As the "Rear Unit" end-play grows.....The Intermediate Sprag Retainer starts to rub the spring retainer. I have seen this get really bad.....But the unit had other issues that caused the direct drum to really get down on the retainer.

Install a TH400 Intermediate Piston Return Spring retainer, Carefully pry the 12 spring out of the 4L80E retainer & reuse them, The TH400 piece is 3x as thick & will not distort.

4L80E Spring Retainer, Notice the rub marks
https://i.imgur.com/M03f2a4.jpg

TH400 Spring Retainer
https://i.imgur.com/CTrkjsK.jpg

Installed in a 4L80E Center Support with the 12 springs
https://i.imgur.com/jJbs9H0.jpg

Re: 4L80E & TH400 Tech.
 

Glad to see this thread alive again.

Re: 4L80E & TH400 Tech.
 

Intermediate Clutch Tech continued....


Intermediate Clutch Pistons
There are 3 different styles of pistons used in TH400's & 4L80E's.

The Stamped Steel "Multi-Piece" piston was used only in TH400 & TH375 units throughout the 70's & 80's as a cost cutting measure, Using a plastic lower retainer & 3 return springs. (Though you can run 6)
DO NOT use this piston in any HP build.....Or ANY build if you have a choice. Not only does it have a very thin work surface, They can also come apart & burn up the intermediate frictions!

Up next is the Aluminum TH400 Piston, Largest work surface of any production piston. Has a higher "Installed" height than a 4L80E Piston allowing you to set a fullsize Wave Plate OR a Flat Steel directly on the Piston. Has 12 return spring pockets. Most production TH400 only used 3 of them.

Last up is the 4L80E piston. Very similar to the TH400 version.....Albeit 2 important differences.
1. The Counter Bore is larger to allow use of a Spring Steel Wave Plate, The Wave has teeth that center it on the Counter Bore.
2. Has a shorter Installed Height to make the "Crests" in the Wave the same height as a Aluminum TH400 Piston.

I prefer the TH400 Piston because I prefer 3 Friction Intermediate set-up's......It takes up some of the height/distance when building a 4L80E. It's a absolute MUST when not running a Wave/Cushion Plate in the Intermediate Clutch!!!!

The 4L80E piston is a decent piece but as I stated......You HAVE to run the 4L80E Wave Plate, If you don't.....The first Steel/TH400 Wave will set on the Case Lugs NOT the Piston & cause the steels to wear on the case & put aluminum debris in your unit.
The Piston will also have to move about .040" before making contact making whatever clearance you measured incorrect.

The 4L80E Wave Plate is the most effective at cushioning the 1-2 shift.

The TH400 Wave Plate allows a little more of a crisp 1-2....But not shock the Intermediate Sprag to bad.

Unless your running a Aluminum Direct Drum with a 36 Element Sprag or a "Fly Weight Car".....I DO NOT under any other circumstances recommend omitting the Wave/s altogether!

I recommend running 12 return spring in all builds, This allows more pressure to build before the piston starts to move improving 1-2 shift feel. If building a 4L80E....Use the original springs, If building a TH400 CK Performance sells spring kits.
Running all the springs also makes 2-1 & 3-1 downshifts "Cleaner"

Stamped Steel Piston
https://i.imgur.com/SbLMjIO.jpg


Failed Stamped Steel Piston
https://i.imgur.com/SR7k2Hu.jpg

4L80E Piston(left) & a TH400 Piston(right)
https://i.imgur.com/G20KQO4.jpg

4L80E Wave(left) & a TH400 Wave(Right)
https://i.imgur.com/pMziqpU.jpg

Re: 4L80E & TH400 Tech.
 

this work great in firefox, https://addons.mozilla.org/en-US/fir...t-fix/?src=api

Re: 4L80E & TH400 Tech.
 

So running a 5.3 / 2WD 4l80e mated with a NP208 (no vss) would allow everything to work properly in 4LO?

Re: 4L80E & TH400 Tech.
 

Okay guys, quick question. I've got a 4l80e in my 03 2500hd, the converter locks fine around town, until you're on the highway and then it will unlock after about 73mph. I read somewhere that the pcm sends a ground signal to the tcc solenoid. Is this correct?

Re: 4L80E & TH400 Tech.
 

Anyone know where clinebarger went?

Re: 4L80E & TH400 Tech.
 

His thread was very helpful glad I was able to get answers to my questions before he left. Ill leave the transmissions to pro next time took to many hours to figure everything out ill just take it to a shop. Problem is not too many shops here do mods mostly just stock rebuilds.

Looks like he stopped posting here back in 2017.
I saw a post from him on other forums seems to still be around not here.

Re: 4L80E & TH400 Tech.
 

hey KELL490 do you remember what forum(s) you saw CLINEBARGER on and what name he was using? I could use some good technical info from him. thank you in advance.

Re: 4L80E & TH400 Tech.
 

He is on LS1 Tech going by same name. Last time I was there anyway.

Re: 4L80E & TH400 Tech.
 

I just google searched his name. If you go to this forum yellowbullet there is a guy named Hutch he is an expert on transmission builds has a sub-forum there. You probably search / post over there find out lot of good information also if you can't find Clinebarger.

https://www.yellowbullet.com/forum/f...splay.php?f=30

Re: 4L80E & TH400 Tech.
 

Thank you dustytrix I appreciate your help 👍🏻

Thank you kell490 good looking out on the knowledge, I'm always trying to learn more lol

Thats what I like about this forum, most people are genuine and willing to help each other.

Re: 4L80E & TH400 Tech.
 

Is clinebarger still active here?

Did a 4l80 in my 73 and the tailshaft won't stop leaking 2 bushings 3 seals and all I've made it do is leak worse.

Re: 4L80E & TH400 Tech.
 

Good thread, thanks for posting.

Re: 4L80E & TH400 Tech.
 

It looks like your driveshaft may be too long. The slip yoke should not go all the way into the tailshaft on the transmission. It should stick out about 3/4 to 1 inch.

Re: 4L80E & TH400 Tech.
 

Google 4l80e rear seal and bushing issues. I believe there were two different bushings used over the years. Something like 40 or 50 thousands difference on the inside diameter.

Re: 4L80E & TH400 Tech.
 

It's out about 1-1/8

Re: 4L80E & TH400 Tech.
 

Ah, ok. The one pic showed the yoke all the way in.

Re: 4L80E & TH400 Tech.
 

a pic from the mockup. The yoke is long almost twice that of my 400 yoke I replaced