4L80E rebuild for 1100hp questions
- Thread starter primetime
- Start date
*Are those just shadows I'm seeing on the Pump Cover/Stator?.....Or did pump gear wear a rut in it?
*Was the Forward Clutch burnt down?? Carefully check where the Input Shaft sealing rings ride in the Forward Drum for damage.....The most common failure in 4L80E's!
*Take some Red Scotchbrite & clean up where Bushings ride on the Main Shaft which makes it easier to visually inspect.
Lay the OD Carrier on the bench & Insert the Overrun Hub/OD Sun Gear into the Carrier, Press straight down & turn the Overrun Hub. IF you feel any roughness.....The captured bearing in the OD is bad! The Carrier can be disassembled to change the bearing using Sonnax part# 34821-01.
*Was the Forward Clutch burnt down?? Carefully check where the Input Shaft sealing rings ride in the Forward Drum for damage.....The most common failure in 4L80E's!
*Take some Red Scotchbrite & clean up where Bushings ride on the Main Shaft which makes it easier to visually inspect.
Lay the OD Carrier on the bench & Insert the Overrun Hub/OD Sun Gear into the Carrier, Press straight down & turn the Overrun Hub. IF you feel any roughness.....The captured bearing in the OD is bad! The Carrier can be disassembled to change the bearing using Sonnax part# 34821-01.
There is about an 1/8th side to side movement when I put the input shaft into the forward drum. Is this normal? Video of overrun hub here:
One set of frictions and steels looks pretty bad. About 3 frictions/steels were stuck together and didn't come apart like the other (direct?) set. I'm assuming it's the forward. Perhaps you can tell based on the stack seen in the following pics? It will be obvious with the thickness differences of the steels when I clean them and check them with the micrometer. (unless someone rebuilt this and used the same thickness steels in the forward and direct lol) Closer pics of the stator also included.
One set of frictions and steels looks pretty bad. About 3 frictions/steels were stuck together and didn't come apart like the other (direct?) set. I'm assuming it's the forward. Perhaps you can tell based on the stack seen in the following pics? It will be obvious with the thickness differences of the steels when I clean them and check them with the micrometer. (unless someone rebuilt this and used the same thickness steels in the forward and direct lol) Closer pics of the stator also included.
Last edited:
Pump looks really good!!! Mainshaft is serviceable with some new bushings in the Sun Gear Shaft.
Those Forward Frictions are beyond smoked & the Forward Drum is ruined. I can see where the Input Shaft ate into the Sealing Ring Lands.
You have a few options here.....
*Buy a reman drum form a transmission part supply house that's already sleeved.
*Buy a sleeve, Machine the Drum, & Press the sleeve in yourself. HERE
*Buy Oversized Sealing Rings which still requires machining the drum.....But no Sleeve is involved. HERE
Both Sonnax & Durabond make world class bushings....Can't go wrong with either!!
Push straight down on the OD Carrier & turn it real slow.....If it feels "Bumpy", The Bearing is bad.
Those Forward Frictions are beyond smoked & the Forward Drum is ruined. I can see where the Input Shaft ate into the Sealing Ring Lands.
You have a few options here.....
*Buy a reman drum form a transmission part supply house that's already sleeved.
*Buy a sleeve, Machine the Drum, & Press the sleeve in yourself. HERE
*Buy Oversized Sealing Rings which still requires machining the drum.....But no Sleeve is involved. HERE
Both Sonnax & Durabond make world class bushings....Can't go wrong with either!!
Push straight down on the OD Carrier & turn it real slow.....If it feels "Bumpy", The Bearing is bad.
Ok, so the “wide” 34016-W stator bushing isn’t necessary then and the durabond that came in my kit will be fine. Perfect! I plan on changing out every bushing. Thank you looking over all the pics and for providing options on the forward drum. I’ll probably take the sleeve/machine route. I’ll recheck the OD bushing.
I just realized where the confusion is on the intermediate drum setup. The plan is to order jakes 36 element sprag aluminum direct drum but I don't know if he makes them to be used with stock size intermediate frictions/clutches. I plan to ask. He may very well use FORD clutches.
The outer race of the sprag is the hub for the intermediate frictions.... and this hub is taller/ deeper than the original hub (stock smaller sprag).
This allows for an extra friction to fit. So the thinking here if the setup is made to use with stock size int frictions/clutches is:
-A 4L80E thin intermediate piston (late 4L80E) with integrated waved steel
-4 OEM THM400 "Waved" intermediate frictions (TH400 Borg-Warner)
-4 OEM thickness 4L80E steels (may need a few 0.100" thick steels (OEM THM400 thickness) to substitute and reduce clearance)
-A billet backing-plate machined to give proper clearance for a 4 count clutch assembly
For peace of mind, I may just have the center support machined for use with a torrington bearing (rollerize it) and also rollerize the planet.
The outer race of the sprag is the hub for the intermediate frictions.... and this hub is taller/ deeper than the original hub (stock smaller sprag).
This allows for an extra friction to fit. So the thinking here if the setup is made to use with stock size int frictions/clutches is:
-A 4L80E thin intermediate piston (late 4L80E) with integrated waved steel
-4 OEM THM400 "Waved" intermediate frictions (TH400 Borg-Warner)
-4 OEM thickness 4L80E steels (may need a few 0.100" thick steels (OEM THM400 thickness) to substitute and reduce clearance)
-A billet backing-plate machined to give proper clearance for a 4 count clutch assembly
For peace of mind, I may just have the center support machined for use with a torrington bearing (rollerize it) and also rollerize the planet.
Last edited:
What about enlarging the feed passage on the center support from .067 to 0.125 with drill bit? I had forgot to ask about that. (see image below)
Also Jake recommends to drill a bleed release hole in the direct drum 0.050 - 0.060" if using his brake. I forgot to list that as one of the holes to drill. Lots of drilling and deburring to do!
Also do you replace the OEM output carrier thrust washer and replace it with a self lubricating thrust washer? Happen to have a part number on that washer? I believe it's number 268 circled in red below?
Last edited:
I've seen way worse than that, The important thing is that it's flat. Sand/Media Blasting is the best way to clean those up.
Sounds good!
Is the sun gear mod worth doing?
Yes....Enlarge the lube hole in the Center Support.....It lubes the Intermediate Sprag & Clutch.
I was using the self lubricating washer from CK, But it has gotten harder & harder too get parts from them in a timely manner.....So I went back to what I did for years....Use a brass output thrust washer. 268 in your diagram. If yours is in good shape....Use it.
*Your 2005 core most likely only has 2 thrust locating holes on the top of the Output Carrier.....Use a Mill or Drill Press to drill the other 2
That's a 4L60E Input Sun Gear....No good on a 4L80E as the lube circuits are completely different.
Ya someone had mentioned "sun gear oil mod" so I'm not exactly sure what they mean. I'll find out.
Yep, only looks like 2 holes. I'll get it drilled and get a 4 tang metal washer 34268
So with regards to measuring endplay, per some of your notes in other threads:
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. Since I will be using a billet rollerized forward hub from jakes, the end play should be zero for this measurement then?
On a stock setup, that would have end play, where should the endplay measurement be taken and should a feeler gauge or SAE Dial Test Indicator be used?
Reaction Carrier to Center Support looks like endplay should be .008"-.015".
To measure Reaction Carrier to Center Support endplay, I stack the gear train up to the Direct drum, Place the Forward Hub over the Main Shaft, Hold the forward hub down with my palms and lift up the center support to separate it from the Reaction carrier?
To measure total rear unit endplay, I just lift up on the output shaft while the transmission is in the holder completely assembled using the SEA dial, correct?
To measure front unit, I flip the trans over completely assembled and lift up on the input shaft?
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
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. Since I will be using a billet rollerized forward hub from jakes, the end play should be zero for this measurement then?
On a stock setup, that would have end play, where should the endplay measurement be taken and should a feeler gauge or SAE Dial Test Indicator be used?
Reaction Carrier to Center Support looks like endplay should be .008"-.015".
To measure Reaction Carrier to Center Support endplay, I stack the gear train up to the Direct drum, Place the Forward Hub over the Main Shaft, Hold the forward hub down with my palms and lift up the center support to separate it from the Reaction carrier?
To measure total rear unit endplay, I just lift up on the output shaft while the transmission is in the holder completely assembled using the SEA dial, correct?
To measure front unit, I flip the trans over completely assembled and lift up on the input shaft?
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
That is correct!
I used to do this by feel....But member P10crew built me a (Absolutely Beautiful) fixture for doing it. You just need it stacked to the Center Support.....Hold/Push down on the Center Support & Lift up on the Reaction Carrier.
NO.....Assemble the unit up to the Center Support (with the beveled Snap Ring installed).....You DO NOT need the Reaction Carrier installed for this! Makes it easier/lighter as it does not affect rear endplay.
*You will need to make adjustment here, So the last thing you want to do is assemble the whole trans & have to tear it all the way back down to change a shim.
*Once you get the total rear unit endplay correct.....Then you can fully assemble up the to the Center Support & torque the Center Support hold down bolt.
Parts list that does need to be installed to check rear unit endplay (Top to Bottom).....
*Beveled Snap Ring.
*Center Support.
*Thin (Fretting) Snap Ring.
*Rear Sun Gear to Center Support Bearing.
*Rear Sun Gear.
*Rear Internal Gear to Rear Sun Gear Bearing AND the factory .041" shim!!!
*Output Carrier (Only to keep everything assembled & center the Sun Gear)
*Output Shaft to Internal Gear Bearing.
*Output Shaft.
*Selectable TH350 Shims.
*TH350 Bearing.
Input Shaft needs to be pointing straight up, Now.....There IS free play between the OD Carrier & Input Shaft Snap Ring.
*You will need to lift up on the shaft 'till the Snap Ring barely touches the OD Carrier & ZERO your Dial Indicator.
*However much further the Input Shaft will lift IS the Front Unit Endplay.
*You're not going to be able to see the Input Shaft Snap Ring.....Got to go by feel!
Similar threads
