4L80E Transmission troubles, DTC 86

[TNDRIVER]

Thanks! That's a great resource to add.

I have been using:

- Technical manual stuff https://www.hummerpartsguy.com/TRANSMISSION-4L80E_c_2823.html

- The ATSG 4l80e manual and the GM 4L Transmissions: How to Rebuild and Modify books


My 4rth planetary carrier has 4 satellites, helical gears. I'm guessing the rear output planetary will be the same.
I have heard that the original humvee 4l80e's should have straight cut gears.

View attachment 963450
Overall this one was in great shape.
I flipped the planetary upside down and all the satellite gears and their needle roller bearings fell out. Curses...
Then spent 2 hours trying to find a single missing needle bearing and finally found it stuck to my magnetic lamp.

I also decided to open the 4rth gear clutch hub to get at the piston seals which were showing signs of tearing at the edges. The sealing surfaces were clean with no scratches or debris inside.
Of course it turns out I need to order a special tool to reassemble that piston without damaging the seals but I'm glad I did it anyways.

I think the most time consuming part of this project will be cleaning everything.

Went back and looked at this pic again............. the center shafts on the gear are "fixed" in place, should not fall apart like this.

 

[TNDRIVER]

Went back and looked at this pic again............. the center shafts on the gear are "fixed" in place, should not fall apart like this.

Pulled these out of my project box. These are 5 gear planets for a 4l85 but they are the same. WARNING, this may not work, I have no idea what I'm doing!

 

[TNDRIVER]

Pulled these out of my project box. These are 5 gear planets for a 4l85 but they are the same. WARNING, this may not work, I have no idea what I'm doing!

 

[TNDRIVER]

YUP, pictures will have to wait for my tech guy tomorrow.

 

[TNDRIVER]

YUP, pictures will have to wait for my tech guy tomorrow.

As promised, my tech guy showed me how to do this, charged me double.
The "tabs" on the"back" fix the center in place, one-half staked on each one. The opposite side is where the race car guys TIG weld the shaft so it "never" comes out. They don't care to rebuild these anyway. Care should be taken, about year 97 I believe the sun gear got changed along with the oiling on these. The year is on the tag on the right rear of the tranny. Hope this helps.

 

[LeafDriver]

The "tabs" on the"back" fix the center in place, one-half staked on each one. The opposite side is where the race car guys TIG weld the shaft so it "never" comes out. They don't care to rebuild these anyway. Care should be taken, about year 97 I believe the sun gear got changed along with the oiling on these. The year is on the tag on the right rear of the tranny. Hope this helps.

That's great to use as a comparison, I had a look at the 2 output planetary assemblies and they were staked the same way as your pictures, though I only had 4 gears on each. All were in good condition minus more clutch material from the torque converter which had to be cleaned out.

Below is the planetary assembly that goes on the input shaft, if you remove the snap ring the top plate can be removed, this holds the center pins for the planetary gears and they can fall out pretty easily if you flip it the wrong way.

 

[TNDRIVER]

That's great to use as a comparison, I had a look at the 2 output planetary assemblies and they were staked the same way as your pictures, though I only had 4 gears on each. All were in good condition minus more clutch material from the torque converter which had to be cleaned out.

Below is the planetary assembly that goes on the input shaft, if you remove the snap ring the top plate can be removed, this holds the center pins for the planetary gears and they can fall out pretty easily if you flip it the wrong way.
View attachment 963907

Over drive planetary. You can purchase the needle bearings to rebuild these if needed. Up until the latest trucks, they were 4 gear planets. If they don't have a ton of miles on them they are pretty tough.

 

[LeafDriver]

Marinating clutch packs.
Output sub assemblies are just about complete, I installed a sonnax hp-4l80e-01 upgrade kit, heres hoping it works as intended.



Forward clutch pack assembly, I didnt have the special tool to compress the spring plate so I used a number of clamps (as above) and the old clutch hub wrapped in painters tape (below) to reseat the spring plate after replacing main outer piston and the sonnax upgraded springs, very fiddly but it worked.
It's important to measure the stock steel clutch plates and compare them with the new ones to figure out which ones need to be used.



Also a comparison of the stock (left) forward clutch hub and the sonnax extreme duty forward clutch hub, which I just realized I should should have that plastic washer replaced with a thrust bearing which I'm sure is lying around somehwere.

I'll have to wait for the replacement direct clutch drum (top left of image) to come in before completing this sub assembly, while it sort of looks serviceable from the inside it's quite badly smoke on the outside.