4L80E & TH400 Tech.

[clinebarger]

Photobucket has decided to extort their members, I will have NO part of it & will no longer be posting to this thread now that it is basically useless.

[indymachinist]

Originally Posted by clinebarger

Photobucket has decided to extort their members, I will have NO part of it & will no longer be posting to this thread now that it is basically useless.

This is a shame. Photobucket used to be great. It has slowly gone down hill over the years and is now 100% traah.

I have switched to imgur and am resonably happy with it.

Photobucket basically ruining this thread is a tremendous loss.

[crakarjax]

Originally Posted by clinebarger

Photobucket has decided to extort their members, I will have NO part of it & will no longer be posting to this thread now that it is basically useless.

FYI there are chrome and firefox extensions that modify the links to non-blocked copies from photobucket -- so far they seem to work well.

https://chrome.google.com/webstore/d...fegnfnflicjjgj

[kell490]

Just wanted to say thanks for this thread I rebuilt my TH400 using these modifications everything worked great I didn't do the full manual I did disable the auto shift out of 1st gear I went with the 34 Element Sprag upgrade over the roller clutch. Too bad about the photobucket it's affecting 1000's of forum threads on the internet. There seems to be a move to stop allowing free cloud storage across the board not sure what the problem is be nice if they at least allowed the existing photo's to stay.

[DieselSJ]

Originally Posted by crakarjax

FYI there are chrome and firefox extensions that modify the links to non-blocked copies from photobucket -- so far they seem to work well.

https://chrome.google.com/webstore/d...fegnfnflicjjgj

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

[clinebarger]

Originally Posted by crakarjax

FYI there are chrome and firefox extensions that modify the links to non-blocked copies from photobucket -- so far they seem to work well.

https://chrome.google.com/webstore/d...fegnfnflicjjgj

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


TH400 Spring Retainer


Installed in a 4L80E Center Support with the 12 springs

[Dustytrix]

Glad to see this thread alive again.

[clinebarger]

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



Failed Stamped Steel Piston


4L80E Piston(left) & a TH400 Piston(right)


4L80E Wave(left) & a TH400 Wave(Right)

[jertho]

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