Just Fishing's 09 Tahoe Build thread

[Just Fishing]

One more upgrade would be a proactive replacement of the 4-5-6 clutch hub and shaft.
Apparently, it's a known weak point.
shafts break, and the welds fail.
Lots of different updates per sonnax for the OEM to fix it.
they offer one, but it's $$$$$$

They also mention that the oem unit was only rated for 400hp.
I'm a little worried about "Shock" due to aggressive shift tuning.

and I'm not sure if I'll exceed the rating or not, but I think there is a very good chance of it...

I'm debating about replacing it with an OEM unit proactively.
Assuming I can find one in stock.

 

[Just Fishing]

Durabond bushings are good. Make sure you have the correct driver tools or they mushroom super easy

Thanks, i just checked my current bushing drivers and confirmed only a few of them actually fit bushings in this transmission.
I'll get another set ordered as soon as my amazon pump rotor arrives and is returned that is...

 

[pwtr02ss]

Do all the upgrades you can while it's out. It's always "damn, I should've just done that while I had it out" if it breaks.

 

[Just Fishing]

Do all the upgrades you can while it's out. It's always "damn, I should've just done that while I had it out" if it breaks.

Yeah, that's always the problem...
Ugg.

parts prices for the 6l80 makes my wallet hurt.

 

[pwtr02ss]

Yeah, that's always the problem...
Ugg.

parts prices for the 6l80 makes my wallet hurt.

Just price out buying one with those upgrades that someone else did. It makes it easier

 

[Just Fishing]

Just price out buying one with those upgrades that someone else did. It makes it easier

If not for the engine being way over budget, i would do all upgrades.

But for this, i can't have it leave me stranded in the desert.

More reading to do, i don't see much mention of those shafts breaking unless we are talking boosted.


And i have a few more tools on order.
Nice speedy amazon refund went towards some drum tools, and a nicer bushing driver kit.

And now i have a drum to test on since it's getting replaced.

 

[pwtr02ss]

If not for the engine being way over budget, i would do all upgrades.

But for this, i can't have it leave me stranded in the desert.

More reading to do, i don't see much mention of those shafts breaking unless we are talking boosted.


And i have a few more tools on order.
Nice speedy amazon refund went towards some drum tools, and a nicer bushing driver kit.

And now i have a drum to test on since it's getting replaced.

Best I remember, the hard parts are pretty stout. I do remember reading about the drum issues that you mentioned. You already have all the pump and valve body upgrades, along with torque converter. I'd only replace the bushings that show wear. Leave the rest. I like the Teflon coated bushings as well. Be warned. They don't look the best after they've been beating around in the pack, just file the little places you see, very lightly. Not on the Teflon surface though. Just the places in the brass. I've never had a problem with that method.

 

[Just Fishing]

Most of what I have in that transmission looks fantastic.
I have yet to pull the rear support stuff, but the tool for it just arrived today.

It's going to be exciting soon!

I also got the shipping notice for my rods last week, but I don't see any action in the tracking information...

So, it looks like I might be doing the transmission before I complete the engine.


Oh well, should be easier to install the transmission and t-case as one unit.
Lifting in and then rolling back into place, with the t-case above the one crossmember that can't be removed.

 

[Just Fishing]

Best I remember, the hard parts are pretty stout. I do remember reading about the drum issues that you mentioned. You already have all the pump and valve body upgrades, along with torque converter. I'd only replace the bushings that show wear. Leave the rest. I like the Teflon coated bushings as well. Be warned. They don't look the best after they've been beating around in the pack, just file the little places you see, very lightly. Not on the Teflon surface though. Just the places in the brass. I've never had a problem with that method.

Part of my plan is to check the fitment of the new bushings vs the ones installed.
Then I believe that should help make my decision related to how worn they are.

There are ones like on the input shaft, they recommend replacing each time.
tiny little guy.

I also want to do the output shaft bushing.

When I pulled this thing, I noticed how much end play I have.
I swear I was like 1/8th of an inch.
Apparently, the spec is something around 20 thousands.

So, I'm expecting some wear to be found.
then the fun of the shimming...
Not much information about that, but there are kits that are sort of hard to find.



But in the end, this transmission worked fine.
This is mostly to ensure that metal didn't make its way from the pump into the internals.

 

[pwtr02ss]

Part of my plan is to check the fitment of the new bushings vs the ones installed.
Then I believe that should help make my decision related to how worn they are.

There are ones like on the input shaft, they recommend replacing each time.
tiny little guy.

I also want to do the output shaft bushing.

When I pulled this thing, I noticed how much end play I have.
I swear I was like 1/8th of an inch.
Apparently, the spec is something around 20 thousands.

So, I'm expecting some wear to be found.
then the fun of the shimming...
Not much information about that, but there are kits that are sort of hard to find.



But in the end, this transmission worked fine.
This is mostly to ensure that metal didn't make its way from the pump into the internals.

On the end play stuff, I believe they make thicker/thinner washers. I check every 4L60 that we've built but they've all went right back together and been within spec. They have all been at the very top of the spec but I haven't had issues with them. I glad you're tearing into one. When the day comes, I'll have some questions for you!

 

[Just Fishing]

First casualty found!
2-6 wave plate was broken in 3 pieces

I saw this in one of the precisions 6l80 teardowns.
He did say, if he found one there will be more.

Who knows how long it has been like this.

 

[pwtr02ss]

First casualty found!
2-6 wave plate was broken in 3 pieces
View attachment 366321

I saw this in one of the precisions 6l80 teardowns.
He did say, if he found one there will be more.

Who knows how long it has been like this.

Now you know for sure you made the right call! Last 60 we tore down had 2 broken frictions in the 3/4 and it still drove...amazing how much can be wrong and they still work, yet one tiny thing, and they quit

 

[Just Fishing]

Now you know for sure you made the right call! Last 60 we tore down had 2 broken frictions in the 3/4 and it still drove...amazing how much can be wrong and they still work, yet one tiny thing, and they quit

Yeah, i was guessing with the over pressure issue in the converter, the trans didn't have long.

I also confirmed the pressure regulator in the pump was pretty much worn out.
but that's a common issue
wear only on the one side of the valve... weird.

and i pulled the sprag apart and did some cleaning.

I watched a youtube vid and they mentioned that the sprag needs to be pressed apart or some nonsense.

I had no issues removing the sprag element from the housing

I can't find a listing for just the sprag anywhere.
OEM has a plastic double cage.

I rinsed it out, cleaned up the surfaces with some oiled up 600 grit like you do on the old 4l60s, cleaned, oiled and popped it back together.

It's so weird that i can't replace just the sprag element.


and i have the rear support fully disassembled.
confirmed no metal found anywhere in it.

 

[pwtr02ss]

Excellent progress!

 

[Just Fishing]

Sonnax 4-5-6 hd kit is on order.
I also ordered a fresh set of steels with that.

Nothing wrong with the ones i have, but it seems like a good idea assuming the apply force has been bending them a bit.

 

[pwtr02ss]

Sonnax 4-5-6 hd kit is on order.
I also ordered a fresh set of steels with that.

Nothing wrong with the ones i have, but it seems like a good idea assuming the apply force has been bending them a bit.

You did raybestos frictions, no?

Any particular reason behind that brand? I'm only asking because Ive used both. I have raybestos in the avalanche but I only did that because the Kolene steels I bought were Raybestos and they recommended the High Energy frictions to pair with them. I actually prefer the borg warner clutches though. Neither is a bad choice by any means, I just noticed the borgs soak fluid and hold fluid better. more fluid, better retention, less heat.

Long story short, is that the friction brand preferred in this particular transmission?

 

[Just Fishing]

You did raybestos frictions, no?

Any particular reason behind that brand? I'm only asking because Ive used both. I have raybestos in the avalanche but I only did that because the Kolene steels I bought were Raybestos and they recommended the Stage 2 frictions to pair with them. I actually prefer the borg warner clutches though. Neither is a nbad choice by any means, I just noticed the borgs soak fluid and hold fluid better. more fluid, better retention, less heat.

Long story short, is that the friction brand preferred in this particular transmission?

I have used both ray and alto frictions.
Both are good, but for some reason raybestos seems to have more of a following...

Not much available short of oem, and some aftermarket.
This wasn't much more in the end.

So i ran with it.

And i also read that they suggest avoiding the z pack for a truck application.
The thinner clutches and steels don't do well with heat dissipation and heavy vehicles.

In my vette, i used the kolene coated steels.
Packed as many clutches in the 3-4 as possible.
Used all red alto clutches.
Good stuff, but that transmission shifts pretty aggressively.

In the end i got some f1 type of shifts.
Instant reaction to my manual shifts.
Very gratifying.

It's also 100% mechanical.
In order to keep the pressures up at high rpm, low rpm shifts suffer.
For that, i run a very loose tv setting.
Then i shift manually.

Allows me to cruise at low rpm, but in automatic it shifts way to early.

Works fine for that car, all around it's a violent experience with the early z51 suspension... lol
(I could find an old review from 84 explaining the finer aspects of it better than i could)

Much easier with software controlling stuff.

With the tahoe, i want it to drive smooth, but i do like to feel those shifts.
Quickly, and firmly.

Makes all things feel right in the world.

 

[pwtr02ss]

I have used both ray and alto frictions.
Both are good, but for some reason raybestos seems to have more of a following...

Not much available short of oem, and some aftermarket.
This wasn't much more in the end.

So i ran with it.

And i also read that they suggest avoiding the z pack for a truck application.
The thinner clutches and steels don't do well with heat dissipation and heavy vehicles.

In my vette, i used the kolene coated steels.
Packed as many clutches in the 3-4 as possible.
Used all red alto clutches.
Good stuff, but that transmission shifts pretty aggressively.

In the end i got some f1 type of shifts.
Instant resction to my manual shifts.
Very gratifying.

It's also 100% mechanical.
In order to keep the pressures up at high rpm, low rpm shifts suffer.
For that, i run a very loose tv setting.
Then i shift manually.

Allows me to cruise at low rpm, but in automatic it shifts way to early.

Works fine for that car, all around it's a violent experience with the early z51 suspension... lol
(I could find an old review from 84 explaining the finer aspects of it better than i could)

Much easier with software controlling stuff.

With the tahoe, i want it to drive smooth, but i do like to feel those shifts.
Quickly, and firmly.

Makes all things feel right in the world.

Thanks for the explanation. I never heard much good about the alto frictions so I never used them. Nice to hear that you've had good luck.

Borg is the OEM supplier, or at least has been in all the ones we've done. Raybestos are a great product as well. Either or from what I've read, are the best you can get.

I agree on the zpak for the heavier trucks. The steels over heat and warp too quickly. I have one in my camaro though. I try to get the tolerance just under minimum spec in 3/4 stack. Like .05 too tight. Seems to be just right after initial break in.

 

[Just Fishing]

borg iirc makes one of those brands...
I could be wrong...

Mostly there is a difference in different clutches via the friction material they use.
been a long time since i spent the time looking that crap up.


I want mostly stock feel, but a tiny bit better than the stock paper clutches would be even better.

In the end I won't be doing any burn outs with this thing, hell I don't even speed in this thing.
What I do want is it to last.


And I should have like 90% of what i need to complete the transmission this weekend.
adding the wave plate and the 4-5-6 piston will push this back to next weekend.
So, I'll get done what I can.


Then the engine,
I messaged the seller of my rods to check in with him since the tracking number has 0 activity.
He said I should see activity today.
so far that's a big fat negative.

Lots of fun having engine and transmission parts everywhere...

 

[Just Fishing]

and a little something i learned from one of the many youtube videos i watched on the transmission subject.

There is a little part in the 1234 drum, it fits perfectly on the 2-6 piston spring.
I just took a bar across it and was able to compress the spring.

This was a slight motivation for me to just replace the whole drum so i could have a left-over part.


but in the end, I didn't even put enough pressure to risk damaging that part.


In the video, he actually modified that thing by welding on old steels and made a nice center point for his press.