Just Fishing's 09 Tahoe Build thread

[Just Fishing]

I was watching a video of a power glide and a 4l60 last night, and i have to say how much easier this transmission is.

Not counting the snap ring.

design of the 6l80 is also neat.
there are pistons that are stacked on top of pistons that serve to keep the piston in place.
where the 4l60 had an issue to push on the clutches at high rpm.
the 6l80 has an extra piston to prevent that.
(Covered in the build video I linked).

neat design.
And I also like how it doesn't need the case to seal or pass fluid through.
valve body mates right up to the different modules.

 

[pwtr02ss]

Nice progress! Thanks for taking the time to document everything so well. This should help me and others in the future. I always forget to take photos when I do something so I'm grateful for those who don't

 

[Just Fishing]

Nice progress! Thanks for taking the time to document everything so well. This should help me and others in the future. I always forget to take photos when I do something so I'm grateful for those who don't

when you get there, there are tons of videos on youtube.
I have a nice little collection of them, each had some extra tidbits that I liked.
As I'm going through this, I find myself revisiting those videos.

one of the best was that linked video, there is also another guy with a ratty looking beard.
he goes over a bunch of different things in his different 6l80 videos.

One of them:

look at his other vids for more detail.
He is one of them that identified that billet piston as being a must have upgrade.

I have watched so many now that they all run together.

 

[Just Fishing]

Well yesterday i took the clutches out of the 1234 and 456 drums, tossed them in the transmission and attempted to mount the new pump in order to check end play.

I could not for the life of me get the pump to fully seat.
Then while rotating the 1234 drum, i noticed it seemed to be hitting that big snap ring.

Me confused,
I started wondering if there was a missing bearing.
Confirmed nope.

Then it hit me.
I never compared the height of the new drum vs the old drum.

The 6l90 has a taller drum, but i never questioned it because i know i ordered the right part number.

So i take it out and compared the new vs old.

Yup, i have a 6l90 tall drum!

I confirmed the pn on the box, and the listing on summit shows a 6l80... lol

So now i get to dissemble the drum, clean off the assembly lube, and return the drum.

 

[Just Fishing]

And last night after figuring that out, i did lots of measuring of the clutch packs.

Ordered new snap rings to tighten and loosen clutch packs

Pita part, the listings for those snap rings is in mm
But my measurements are Inch.

So lots of converting and scratching of my head.

I also found my end play is pretty bad, just like it was when i first pulled the trans.

With the pan off i can see that the clearance issue is from pump to 1234 drum.

Pulling up on the turbine shaft lifts the drum.

So i have a sonnax pump spacer kit on order to tighten that up.

Then moving onto the 2-6 clutch pack that states no selective snap rings are available for it.

Clutch clearance says .050
And if you don't get that, then you did it wrong.

This is the pack that had the broken wave plate.

I have a good .070 clutch clearance there.

Then i noticed there is plenty of room for a thicker snap rung...

Got me thinking.

So i took a snap ring from the 1234 drum to see what happens.

It's technically too long and for a larger circumference...
But it does fit.
And has more tension than the correct snap ring!

Using the thicker of the two options from that drum, i get a nice .059

So yeah, I'm calling that one gtg.

 

[Just Fishing]

Got my new drum today from amazon,
actual next day shipping this time!!!

same PN, and it's the correct part.
This one came in an actual GM box with the rainbow looking "genuine" tag!

Next, I get the fun of exchanging parts, then the wrong drum goes back to summit.

Bday today, so I'm not wrenching on shit...

 

[pwtr02ss]

Happy birthday home slice!

 

[Jimmyy]

Happy Birthday.

 

[Jimmyy]

Bday today, so I'm not wrenching on shit...

Not going to take the torque wrench out for a spin?

 

[swathdiver]

Well yesterday i took the clutches out of the 1234 and 456 drums, tossed them in the transmission and attempted to mount the new pump in order to check end play.

I could not for the life of me get the pump to fully seat.
Then while rotating the 1234 drum, i noticed it seemed to be hitting that big snap ring.

Me confused,
I started wondering if there was a missing bearing.
Confirmed nope.

Then it hit me.
I never compared the height of the new drum vs the old drum.

The 6l90 has a taller drum, but i never questioned it because i know i ordered the right part number.

So i take it out and compared the new vs old.

Yup, i have a 6l90 tall drum!

I confirmed the pn on the box, and the listing on summit shows a 6l80... lol

So now i get to dissemble the drum, clean off the assembly lube, and return the drum.

Happy Birthday, it was my little brother's too!

Precision Transmission mentions the different drums in his videos lately, someone at a factory must've sent a bunch out in the wrong boxes!