What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Geotrash

Dave
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I did it on mine back in 2019 after dropping the pan and doing a fluid/filter change. I change out that filter once a year.View attachment 389431
Right, I forgot that until I revisited skpyle's thread. I like your filter choice better too. Looks like you plumbed yours in before the radiator's fluid cooler, yes?
 
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I'm curious how messy or clean it would be to change out the fluid by having that filter removed and a bucket underneath and running the engine for a bit then adding fluid through the trans dipstick tube.

Usually I remove the upper radiator trans line and insert a barb hose adapter into the jiffy tite fitting with a hose running to a bucket.

Thinking maybe saving a step and being able to change the fluid while the remote filter is being changed?
 

Just Fishing

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I'm curious how messy or clean it would be to change out the fluid by having that filter removed and a bucket underneath and running the engine for a bit then adding fluid through the trans dipstick tube.

Usually I remove the upper radiator trans line and insert a barb hose adapter into the jiffy tite fitting with a hose running to a bucket.

Thinking maybe saving a step and being able to change the fluid while the remote filter is being changed?

I found it pretty much drips straight down.
I just used a 5-gallon bucket and propped it pretty close to the rim to prevent splashing.

My lines might be different since I have 1/2in, so it might have more spray with 3/8in?
So tread carefully, maybe a helper to quickly shut it off while you watch

I was also thinking about taking an old filter and cutting off the bottom, then I could use that as a shield.
probably next time I mess with it, I'll do that.
 

iamdub

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Second question: the transmission guy says lots of tuners jack the line pressures up and kill the pumps early in the 6L80. He said he'd look at the BB tune to see what they did. But he thinks that might be why it died at 140k (tuned since 99k). I've never heard of a BB tune killing a trans. Do you think there's any validity to this? I wouldn't be so quick to blame BB. If anything it's an indirect cause, as my right foot would have had a lot to do with it.

I really doubt it. Jacking up the line pressure is a very rookie move. I can't see BB doing this. A good tune should actually extend the life of the trans since it would reduce the shift confusion, slip, unnecessary shifts and general slop the factory has programmed in to make it soft and comfy.
 

Just Fishing

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back in the day they would boost line pressure with a part, this was pretty common on the earlier units.
I haven't heard of a pump dying due to line pressure being boosted, but who knows.

These days you can do it via a tune, and what I did was to just boost the pressure by a few percent in the clutch pressure settings.
Pretty much I didn't like how 2-3 shifted, so I would boost that until I was happy.
I also played around lightly with the oncoming pressures to help speed up apply and remove the delay and a slight slip that was present.

Do i know what I'm doing?
nope!!

With my fresh transmission with good clutch pack clearances, I didn't need much to make me happy.
I'm pretty much on a stock tune at this point, I think I have 1-4% pressure boost in some gears.
but mostly I have that since the tune was for a 5.3, and I'm no longer running a 5.3.
 

Geotrash

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I'm curious how messy or clean it would be to change out the fluid by having that filter removed and a bucket underneath and running the engine for a bit then adding fluid through the trans dipstick tube.

Usually I remove the upper radiator trans line and insert a barb hose adapter into the jiffy tite fitting with a hose running to a bucket.

Thinking maybe saving a step and being able to change the fluid while the remote filter is being changed?
That's how skpyle did it in his build thread.
 

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