4L80E rebuild for 1100hp questions

Joined
Mar 7, 2020
Messages
170
Location
OH
I'm looking at rebuilding a 4L80E to hold 1100hp. My car is a 3700 lb street car 2000 camaro and I don't want every shift on the street to snap my neck. I do however want firm shifts when going all out with the car. That being said, I want this transmission to live and will be launching it at the track from time to time with no transbrake. I'm considering the CK Steel billet main shaft 4l8CC/BMS-1L and the forged steel billet rollerized hub 4L80CC/BFCH-A as 2 main upgrades. I'm also considering the 4L80ECC/MSRK kit. I see there's alot of stuff posted online to improve the performance of the trans, and was wondering if I shoud perform the following modifications as well in addition to the above in a build where I will follow the 4L80ECC/MSRK instructions exactly. I plan to source a 2004 4L80E 2wd.

1. TCC Regulator mod - Sonnax drop-in TCC Regulator Valve part#34994-01K

2. AFL Valve Bore - Ream the AFL Valve Bore & install a oversized AFL. Sonnax S34741LK if you have the tool, otherwise Trans Go part# 48-ACT-TL.

3. Sonnax Transmission Boost Valve & Sleeve 4L80E-LB1 (is this needed after performing the mods in the 4L80ECC/MSRK instructions?

4. Use a wave plate in the direct drum but ensure that it is from a TH400, and not a 4L80E as the TH400 is stronger. 0.060" 12 lug

5. Drill a hole in the direct drum even if not going with a brake. A .050" ish hole on the outer edge of the piston bore will help release faster on a 3-2 downshift.

6. Use a wave plate in the intermediate clutch in EVERY 4L80E/TH400 build that uses an iron direct drum. This helps with wear on the intermediate sprag.

7. Plug the reverse feed in the center support, as this keeps 3rd/Reverse oil from leaking between the Support & Case. I hear a TV Exhaust checkball from a 700R4 works great.

8. Omit checkball #9 as I'm dual feeding the direct clutch and want to speed up reverse apply (Apply of the direct clutch in reverse). Should I do that or drill the apply orifice to .086-.093" to speed up the apply & leave #9 installed?

Some specific questions regarding my parts list below:

1. How critical is the brand of steel plates. 34139EA comes up as a common number for the kit, but the kit includes 5 Direct steels that are .090" and 5 forward steels that are .077", so if you are planning on going all 0.077" in the forward and the direct with the exception of the single cushion, you need to buy 5 more direct steels that are #34128.

2. Should I use Kolene Steels instead?

3. For the wave plate in the direct drum, are we talking a steel cushion plate, waved .060" 12 lug from a TH400 part #34127?

4. Thoughts on using 1 kolene Intermediate steel 0.100" that will be put against the piston #34124K?

5. Since the 4L80ECC/MSRK already comes with a rubber bonded piston for the direct clutch, I won't need 34965G that comes in piston kit 34960A, correct?

6. I read that every 4L80E direct drum has a Bleed Checkball in it, and that some TH400 pistons do not have a bleed as some TH400's used a drum bleed and some used a piston bleed. Since the 4L80ECC/MSRK kit already comes with the direct clutch piston and spring assembly, I should just use that and not need to source anything from a TH400, correct?

7. Do I need to verify correct travel for the reverse band servo and correct pin length? Is there any way to do this without buying the gm tool?

I have the tolerances for end play as follows:

Total Rear Unit.....003"-.008" (Rollerized)
Reaction Carrier to Center Support......008"-.015"
Direct Drum to Forward Hub......003"-.008" (Rollerized)
Front unit.....005-.008" more/greater than the Rear Unit

If I wasn't purchasing the 4L80ECC/MSRK kit, I would perform the following mods but I believe these are already all taken care of when you buy that kit and follow the instructions:

- Use the Brass Thrust Washer that came from the Case Thrust between the Reaction & Output Carriers....Replacing the Plastic Thrust Washer (covered in CK instructions)

-Remove/omit the second from the top Sealing Ring on the Center Support. (covered in CK instructions)

-Omit the "Center Drum" lip seal in the direct drum. (covered in CK instructions)

-Plug the "Direct" Reverse Feed in the Case.....I do not like the thought of ramming a set screw into the Center Support, Loctite the set screw in place in a position where it does not interfere with the Support. The industry standard is to use a parking pawl cup plug. (covered in CK instructions)

-Enlarge the lube hole in the Overrun Clutch housing with a .125" drill bit (covered in CK instructions)

-Replace the Overdrive Sun Gear Bushing with a "Fluted" Sun Gear Shaft Bushing. A bushing kit will only come with 2 sun gear shaft bushings, You will need to purchase a third. (covered in CK instructions)



Anything in the parts list below that I should swap out? Any mods that I am missing?

[Linked Image from cimg0.ibsrv.net]
 
Last edited:
I looked at it, the last rebuild I did on a GM was a TH400 short tail shaft for a Buick. Clinebarger will have all the answers you need, he is one of the best transmission guys around.
 
Most of your post seems to be excerpt's from post I've made in the past.....Everything is still relevant!

*You won't have room to run a wave in the Direct Clutch with 6 frictions, Which you will need at 1000hp.

*Need a billet Input Shaft at this level.....Didn't see it on the list?

*Using the 4L80ECC/MSRK will be easier for you!! Use the Orange Pressure Regulator Spring at this level!

*I use Borg Warner High Energy or Raybestos HD Graphite frictions for these.....Though I've heard good things about the new(ish) Alto High Energy & their G3 line.

*I use Raybestos &/or GM steels on 80E's....But have used Alto Kolene for years on 4L60E 3-4 Clutches.

*A 36 Element Intermediate Sprag is a good idea at this level.....4L80ECC/SCDD.

*Shifts are going to be on the harsh side with the Line Pressure required at this level, No way around it.
 
Hi Clinebarger,

Thanks for your reply! Correct, I got most of this stuff from reading your post and copied them into a single query.

I'll see if CK has 4L80ECC/SCDD in stock which I understand is a cast iron intermediate drum, fitted for the larger 36 sprag. As I understand it, his version will allow me to use the 4L80E frictions and not the ford frictions that comes with other vendors drums fitted for the 36 sprag.

Am assuming my lineup with the CK direct upgraded piston clutch assembly and that iron drum fitted for the 36 sprag will be:

6x direct clutch
6x direct steels
5x forward clutch
5x forward steels
1x wave in the forward (no trans brake so use a wave) use TH400 0.060" 12 lug
4x int clutch
4x int steels
1 in wave, stock style from 4L80E (the steel goes on the steel wave)
1x .106 torqueflite727 snap ring for int clutch
Overrun and Overdrive are stock configurations using the raybestos turbulated steels and borg frictions


- The input shaft I was thinking is 4CC/BMS-1 Will that be good enough?

- I agree, i'm planning to capture the savings by going with 4L80ECC/MSRK

- Borg Warner High Energy Friction and Raybestos steels it is. I have a local WIT near me to source from there as well.

- If the original boost valve needs replace, just replace it with stock and use the Orange Pressure Regulator Spring. Don't use the sonnax as the sonnax boost valve requires the stock spring.

- Tap the center support for a threaded pipe plug, or get a freeze plug as described in CK's kit.

-Rather than omitting checkball #9 off the go, I'll see how reverse feels with it in and if I need to change it, just pull the pan and drill the apply to .086-.093"
 
Last edited:
The 4L80ECC/MSRK kit comes with a HD Intermediate clutch snap ring....No need to procure an A727 snap ring. Also comes with a Park Pawl Plug to plug the case as does the Paper & Rubber kit.

I wish someone made an Aluminum direct drum.....All of the ones I know of require machining to clear the Intermediate clutch pressure plate as they are machined for a TH400.

You can run the CK orange regulator spring with the Sonnax boost valve.....I recently tested it & works well.

With the weight of your car....You can get by with the lower line of billet input shafts.
 
The ck modified drum with the 36 sprag is pretty pricey. If I go for the borg 34 sprag and stock intermediate, can I still run the friction/plate setup as listed with the ck updated direct piston assembly?

Also I read that of using the sonnax boost valve, I shouldn't drill something. Trying to recall what it is that shouldn't be drilled.

Should I use the HD blue pistons made by SAP in the forward and intermediate and use the piston that comes with ck kit for the direct? Or use stock pistons?
 
Last edited:
There is/was never an issue with the OE bonded pistons made by National other than the thin work surface. The Intermediate piston is Aluminum, You're taking care of the Direct clutch with a TH400 piston......The Forward & Overrun will perform just fine with the OE pistons.

As for the direct drum being expensive.....You're playing with the big boys now
grin.gif
 
Originally Posted by clinebarger
There is/was never an issue with the OE bonded pistons made by National other than the thin work surface. The Intermediate piston is Aluminum, You're taking care of the Direct clutch with a TH400 piston......The Forward & Overrun will perform just fine with the OE pistons.

As for the direct drum being expensive.....You're playing with the big boys now
grin.gif



Yeah at 1100 ponies not real sure how you even get that amount to the ground.
 
If using a sonnax boost value/sleeve assembly 4L80E-LB1 with the stock pressure regulator valve, do I still need to drill a bleed into the lube passage in the pump? I'm talking about the .055" to .067" hole between the line pressure and converter charge passages in the pump cover.

It's only when you have the Sonnax 34200-14K replacement pressure regulator valve instead of the stock valve that you can avoid drilling the hole between the line pressure and converter charge passages in the pump cover, correct?

Which is the better route to take?
 
Last edited:
You got it!

*If rebuilding....Drill the "Lube To Line Bypass" in the pump cover & run a stock/stock type regulator valve.
*If upgrading a 4L80E "In Vehicle".....Install a Sonnax "Lube To Line Bypass" regulator valve.
 
Last edited:
Thanks again!

I was looking at the different options for Sonnax chromoly slip yokes for my driveshaft when upgrading, and I see there are several types. If using the 4L8CC/BMS-1L billet mainshaft, which is the correct slip yoke to use?

[Linked Image from cimg6.ibsrv.net]


Also for the 4L60E that I currently have, I'm using a sonnax yoke on it but not sure which one I have? Do the f-body 4L60E's use a yoke that is counterbore or full spline?

[Linked Image from cimg7.ibsrv.net]


I obviously have to use a different yoke to accommodate the 32 splines but I'm told that the 4L80E trans itself is about 1/2" longer than the 4L60E, so my current driveshaft may not work after upgrading to the 32 spline sonnax yoke. I have a Strange Dana S60 rear end and my current PST 3.5 aluminum drive shaft is 39.625" center of U joint to center of U joint. Will obviously have to measure to ensure that the driveshaft doesn't have a slip of less than 0.75
 
Your Yoke needs will depend on the Output shaft not the Main shaft. I recommend running a Fully Splined Output Shaft & a Fully Splined Slip Yoke.

Counterbored Yokes are for use on Bolt-on Yoke Output Shafts.....But this combination has a tendency wobble around & cause vibrations, Especially on 4th Gen F-Bodies.

I'm running the T3-35571HP on my Camaro.....A shorter Yoke will not gain any extra room for driveshaft length as the spline length on the fully splined shaft is right at 5.250".

GM full spline Output part#
Full spline output

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]
 
Thanks!

I read that the 4L60E in the 4th gen f-body does not require the counterbore yoke, so 6081HP is typically used.

Interesting how for the 4L60E the 6081HP has a 3.880 barrel length while the 35571HP that you are using on the 4L80E has the 5.380 barrel length.

What main shaft on the 4L80E would be used for running the 2431HP which has the smaller 3.880 barrel length? Just trying to better understand why there are differences.
 
I'm going to try explaining this to the best of my ability.....Bear with me......

The ONLY reason to run a Counterbored Yoke or a shorter Yoke is to clear the O-ring Boss on a Bolt-On/Fixed Yoke style 4L80E Output Shaft.

With a Fully Splined 4L80E Output.....There is ZERO reason to run a Short &/or Counterbored Yoke.

What you're running on the 4L60E is of no consequence to this discussion, I believe you're concentrated on the wrong component? If your Driveshaft is too long.....It's too long & will need to be shortened & rebalanced.

Here's some drawings to help out.....

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]
 
Bolt-On /Fixed Yoke style Output, If the customer doesn't want to spend the money on a fully splined shaft.....I usually have to machine it for the application/Yoke being used.

This truck had a 4L80E conversion done & someone was asleep at the wheel.....The yoke was hitting the O-ring Boss & beat the torrington bearings in the trans up.

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]
 
Thanks again Clinebarger. Makes perfect sense now. Hopefully the donor 4L80e will have the full spline output and if not, I'll just purchase it separately and run the Sonnax T3-35571HP and go with whatever driveshaft PST recommends that will hold 1200hp.
 
I was looking through CK's parts and I don't believe a Jakes state 5 for example which is rated for 1500hp contains these parts in it, so what are your thoughts on these at my 1200 rwhp power level?

CK 91-96 over-run assembly/ over-drive planet assembly - 4L80ECC/BOC-C
CK 4L80E Billet intermediate pressure plate - 4L80ECC/BIPP-L
CK Press fit Billet Sun Gear shaft - 4LCC/BSGS-L
CK rollerized reaction carrier planet - 4CC/RRC

All these would set me back an additional $1k, and of the CK parts I was planning on just using:

CK COMPETITION STEEL BILLET MAIN SHAFT - 4L8CC/BMS-1L
CK FORGED STEEL BILLET ROLLERIZED CLUTCH HUB - 4L80CC/BFCH-A
CK SUPER COMP DIRECT DRUM WITH 36 ELEMENT SPRAG - 4L80ECC/SCDD
CK Master re-calibration kit - 4L80ECC/MSRK

I'm also strongly considering the Jake's D3 transbrake because foot brake launching this car is probably going to be a joke. I'd rather just have the proper 3 disk lockup converter and launch at 4800 rpms off the transbrake so that I can cut them 1.2x 60 fts all day lol....
 
Back
Top