4L80E & TH400 Tech.

[clinebarger]

Originally Posted by dfarr67

Does the Transgo valve have redesigned lands so as to not wear as quickly?

I looked into Circle-D and I had to go billet$$ for SBC gen1 flexplate otherwise he did have a reasonably priced non billet GM unit I couldn't use.

It has wide lands.

I am OVERLY picky when it comes to converters, Circle D stands behind their products! Never charged me a cent for Cut/Clean or Refresh, And a re-stall is free within a time window.

[indymachinist]

Has anybody here bought the actuator feed limit valve kit from transgo? If so, want to share?

Edit: I bought the kit. For future reference, I will share after I am done with mine.

[indymachinist]

clinebarger, when doing the 91-93 to 94-03 EPC solenoid upgrade, do I need to use a different hold down clamp also? The older style clamp doesn't seem to fit the newer EPC solenoid quite right.

[clinebarger]

Yes, GM part# 8684217

[clinebarger]

Are you building from scratch, Or just pulling the VB & Plate?

I like blocking the 2-3 accumulator because the results are more consistent & repeatable. Dual Fed Directs also affects 2-3 shift feel, As does the Direct Clutch return springs.

Use of Hi-Energy (Flat Face) 4L80E frictions in the Direct Clutch produces a less harsh shift than TH400 Tan Paper frictions once the frictions are broke-in/compressed to their final form.

Friction Modifiers or lack of in the ATF also plays a roll, All my recommendations are based on the use of Dexron III ATF.

The use of Wave Plate/s in the clutch pack also has a tremendous affect.

It seems I'm answering questions with questions, Not my intent.....But I want to give the most accurate advice I can.

[-TheBandit-]

Questions are just fine! The transmission is of unknown build. I am not pulling the transmission from the car, or at least I don't plan to. I was having some trouble with my 2-3 shift sporadically shifting back and forth at cruise after swapping in the ls engine. I also could not get the car to shift 2-3 under wot and in fact any real throttle would cause a 3-2 downshift even though the kickdown switch is disconnected.. After checking the modulator and governor, I decided to pull the valvebody and check for any sticking valves. I decided to install a transgo 400-pro kit while I'm in there.

But when I pulled off the valvebody, I found the reverse feed had a screw in plug. When I removed it I confirmed air passed freely between the 3rd feed hole and the reverse feed hole, indicating to me the seal was omitted i.e dual feed was already done internally. I put the plug back into the reverse feed and I plan to run that as is, but I will not be able to use the transgo plate.

I also found the 2-3 accumulator piston had been locked down against the valvebody using nuts between the piston and the e-clip. I went ahead and installed the transgo supplied spring and took out all the nuts so it's functional again.

I also found the front servo e-clip was broken and floating around under the spring seat. No idea what that might do beyond preventing the front band from applying. I have never had engine braking in 2nd and I assume that's why. I installed a new e-clip.

I am getting ready to put it back together with a stock separator plate, feed holes drilled however I decide and I don't know whether or not I should block the accumulator feed. Looking at the transgo plate, I think they restrict the flow to the accumulator using a small orifice.

I didn't find any sticky valives in the valve body.

[clinebarger]

Pull the governor out & check for the "head" being loose, Measure the "lands" if under .797".....Replace Governor, Check Governor "end-play"....Adjust to .030"-.040" Strike the center of the cover to tighten end-play.

Try .101 2nd feed hole, And .125" on 3rd with the accumulator blocked (They already blocked it by shimming the piston to bottom)

[-TheBandit-]

Thanks clinebarger. I inspected the governor and it seemed to function properly, but I did not measure the lands or check endplay. I will take a look at that if this doesn't work out. Thank you!

[clinebarger]

Forward Hub Tech.......

TH400 Forward Hubs are Cast Iron, Good to around 500 ft lbs in most applications, More if your not shocking it with a big stall or a big hit of nitrous.

4L80E Forward Hubs are Cast Steel, Good to around 750 ft lbs in most applications, Not phased by big stall's or small hit's of nitrous.

Identification.......TH400 Forward Hubs will make a dull thud sound when lightly struck with a wrench, A 4L80E piece will ring like a Bell.

End Play, Forward Hub to Direct Drum specs.......
Using a Thrust Washer..... .008"-.015"
Using a Torrington Bearing....... .003"-.008"

If using a Thrust Washer between the Forward Hub & Direct Drum, You will need to buy a thicker Thrust Washer as no shims are available for this location.
Stock Plastic or Brass thrust thickness...... .059"-.064"
Sonnax Part# 34301-078 ...... .078"
Sonnax Part# 34301-094....... .094" This is the one usually needed.

Rollerizing the Forward Hub.....
This is highly recommended mod.....Almost needed if your trans spends long stints in low gear.

The best fitting bearing to use is a final drive sun gear bearing out of a Ford AXOD Part# E6DZ-7F404-A
Ford has discontinued this part, But Green Sales has them in stock Phone# 1-800-543-4959

Machining the Forward Hub rear thrust pad is necessary, Be very careful on your measurements because you will need to set Forward Hub to Direct Drum end play with the machining.

Start with +.035"......Lets say the bearing is .150", The original thrust is .064"
.150"-.064"=.086", .086"-.035"=.051"........051" is what you need to remove from the Thrust Pad. These are hypothetical numbers!! Measure your new Bearing & old thrust BEFORE machining!!

Checking Forward Hub to Direct Drum end play, Stack the gear train up to the Direct drum, Place the Forward Hub over the Main Shaft, Hold the forward hub down with your palms & lift the direct drum with your fingers.....The play you feel is the end play.....Picture......

[clinebarger]

Bearing....

[clinebarger]

Machined 4L80E Forward Hub next to a stock TH400 Forward Hub

[clinebarger]

Bearing compared to a Thrust Washer.....

[DieselSJ]

Clinebarker, thanks for the 700R4 info in the other thread. Next project is a 4L80E into my dually. Currently a stock 454, but plans are for a diesel swap with torque in the 600-700 range. I have a couple cores to choose from - a 1995 or a 2000. Both come from 1-ton trucks behind small block V8. Which would be the better starting point? Reading through the thread, I'm leaning towards the 2000. Both are same price. Thanks!

[clinebarger]

Originally Posted by DieselSJ

Clinebarker, thanks for the 700R4 info in the other thread. Next project is a 4L80E into my dually. Currently a stock 454, but plans are for a diesel swap with torque in the 600-700 range. I have a couple cores to choose from - a 1995 or a 2000. Both come from 1-ton trucks behind small block V8. Which would be the better starting point? Reading through the thread, I'm leaning towards the 2000. Both are same price. Thanks!

Which ever one is in better shape internally...., I know.....You don't know 'til you open it up.
I would probably go with the 2000 model for the 34 element intermediate sprag.

[clinebarger]

Rollerizing the Output......

Parts needed....
TH350/TH125 Pump Bearing, GM part# 9436851
TH350 Unit End-play Shims (assortment)
If building a TH400....4L80E Pump Bushing (.700" wide)
If building a 4L80E....Sonnax 34006-SP Bushing (Special instructions!)

Before tearing the unit down, Check rear unit end-play & record the reading, This will give a very good baseline when setting final end-play upon assembly.
If you do find a bad Torrington, Sun-Gear, Carrier, Etc in the lower half....This measurement was for naught, But if your reusing everything....It can save alot of time.

Case Bushing installation & Tech....
TH400 Directions
When using a .700" wide '97 & up 4L80E Pump Bushing, You need to leave the bushing sticking up out of the Case about .080". Red Loctite the O.D. of the Bushing before installation. This Bushing has no oil grooves in it, But the Torrington doesn't require the amount of oil that the Thrust Washer did. I haven't had ANY problems with using a non-grooved bushing as lube oil is fed directly to the face of the bushing through a lube hole in the output shaft.

**If you have a TH400 & want a bushing with oil grooves, Use a TH400 Case Bushing, It is only .620" wide so you will lose some support by offsetting the bushing .080" into the Case. I recommend Loctite & Stacking the Bushing in place in this scenario **

4L80E Directions
'91-'96 "Conventional Lube"...... Using a Sonnax 34006-SP, Sit the bushing in the back of the case & mark the location of the 2 lube holes on the lip of the bushing. Take a file & file 2 "V's" though the lip of the bushing. This will eliminate the bushing lip from restricting lube flow to the Geartrain, Case Bushing & Extension Housing Bushing.
Coat the O.D. with Red Loctite. Drive the bushing in from the BACK of the case, This is opposite from the directions that come with the bushing. Seat the bushing all the way & it will be sticking up out of the case far enough to register the bearing without you having to measure.

Note the 2 Lube Holes in the Output Shaft.......
Temporarily install .030 worth of shims over the Bushing inside the case.
Temporarily install the Bearing over the Bushing (Silver side up).
Use TransJel if needed to hold the shims & bearing in place.
Temporarily install the Output Shaft.
IF the 2 lube holes in the Ouput are blocked or partially blocked by the bushing.....You will NEED to chamfer the holes toward the REAR. See picture.
'91-'96 4L80E's lube the geartrian backwards from a TH400, It is imperative that the lube holes on the shaft are open to the area between the bushing & Seal!!

'97 & up Center Lube 4L80E.......Using a Sonnax 34006-SP, Sit the bushing in the back of the case & mark the location of the 2 lube holes on the lip of the bushing. Take a file & file 2 "V's" though the lip of the bushing. This will eliminate the bushing lip from restricting lube flow to the Case Bushing & Extension Housing Bushing.
Coat the O.D. with Red Loctite. Drive the bushing in from the BACK of the case, This is opposite from the directions that come with the bushing. Seat the bushing all the way & it will be sticking up out of the case far enough to register the bearing without you having to measure.
These units do not lube the geartrain from the back of the case, They Lube from the Center Support....The reason there are no lube holes in the Output.

Case Lube Hole Locations


Bushing Modification Drawing


Sonnax 34006-SP, Install with lip toward the rear of the case!


'91-'96 Output Lube Hole Modifications

[clinebarger]

Geartrain Install & Rear Unit End play

Measure the thickness of the 3-Tab selectable Washer & 4-Tab Thrust Washer, (Measure them while stacked together)
Lets say they measure .150" & your pre-teardown end play was .025"......You will want the Bearing & Shims to measure .170".....This will give you about .005" rear unit endplay, You can run as tight as .003" with a bearing on the Output. .008" is my limit.

Install the Shims then the Bearing over the Bushing (Silver side UP, Black side DOWN.

Before stacking the geartrain in the Case, Check the Reaction Carrier End Play buy stacking the unit up to the Center Support on the bench, Use both your thumbs to hold the center support down while lifting the reaction carrier up with your fingers. There is not really a way to use a Dial Indicator here so you have to go by feel.
Set to .008" to .015" using Sonnax shim pack 34006-05

"IF" the old Brass REAR thrust washer is in good shape.......Replace the Plastic Thrust Washer between the 2 Carriers with it, They are about the same thickness (.060") & the Sonnax shims work with it also.

You can now stack the trans up to the Center Support, Install the center support snap ring & check rear unit end play.

Selectable & Thrust on the bottom, Bearing & Shims on top


Bearing & Shim installed in the Case, The Bearing is upside down in the photo!


Check Reaction Carrier End Play, Check Direct Drum to Forward Hub End Play at the same time


Replace the Plastic Thrust on the Output Carrier with the Brass Washer you removed from the Output Shaft.

Plastic


Brass


Final Check Rear Unit End Play

[indymachinist]

So now that my 4l80e is built... how about a slightly different kind of topic.

Proper "care?" of a 4l80e in high horsepower use. Not so much change the fluid etc, but how to treat it.

A few things I have read:

-race in 3rd not overdrive because it engages the front band? and 4th doesn't like high power full throttle shifts

-don't shift into neutral at high speed to prevent over spinning the direct drum

-there was something about how to do a proper burn out but I don't remember what it was

Anything else you guys can think of?

[clinebarger]

Originally Posted by indymachinist

So now that my 4l80e is built... how about a slightly different kind of topic.

Proper "care?" of a 4l80e in high horsepower use. Not so much change the fluid etc, but how to treat it.

A few things I have read:

-race in 3rd not overdrive because it engages the front band? and 4th doesn't like high power full throttle shifts

-don't shift into neutral at high speed to prevent over spinning the direct drum

-there was something about how to do a proper burn out but I don't remember what it was

Anything else you guys can think of?

1. Never race a 4L80E in D4, Putting the shifter in D3 brings on the Overrun Clutches & helps support the Overdrive Roller Clutch.


2. That is correct.


3. With a manual shift valve body....Start the burnout in 2nd....Then shift to 3rd.

With auto shift.......Back into the water box, start in 1st shift to 2nd then to 3rd gear, get into 3rd gear as soon as possible. Pull away from the water fairly aggressively for a few feet, and then lift quickly off the throttle.

[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

[jertho]

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