2004 Yukon 4l60e

[Backdoejr]

So I currently have 2004 4.8 Yukon that’s been my daily driver for the past 2 years I’d say, it finally reached the 180k mile point of its life span and it’s showing, my main concern has been the transmission as of late when I’m on the freeway 1st to 3rd seem to shift fine but 4th is when I feel it starts to struggle, I’ve checked the trans fluid it’s clean thankfully no shiny glitter and makes me wonder what could it be. If anybody can inform me I would much appreciate it

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

If it is the original transmission, it likely needs a rebuild or replacement at that mileage.

@NickTransmissions is our resident transmission expert, and he can join this conversation.

 

[Backdoejr]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

If it is the original transmission, it likely needs a rebuild or replacement at that mileage.

@NickTransmissions is our resident transmission expert, and he can join this conversation.

I’m welcome to be here I’m glad I’ve been able to find a group where I could get help and learn more about my gmt800 but yea I’m still on the original trans and kinda figured it would lead that direction but I attached a few screenshots of around th transmission from a vid I took sorry for the yap

 

[Backdoejr]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

If it is the original transmission, it likely needs a rebuild or replacement at that mileage.

@NickTransmissions is our resident transmission expert, and he can join this conversation.

@NickTransmissions whenever your available brotha I would greatly appreciate your insight

 

[PNWYukon]

At 187,000 I replaced the separator plate and installed the Transgo shift kit and the 2005 Tahoe went another 54,000 miles. One shift spring was broken inside the valve body and the separator plate had one check ball almost rammed through. All done with transmission still in truck. Really depends on how bad you think it is.

 

[Marky Dissod]

Until Nick responds, Murphy says that, after 180k miles, to get ready to either have your 4L60E rebuilt or replaced.
You mentioned that you checked the ATF and found it clean. OK, but what color was the ATF?
The darker the ATF, the better to drop the pan and let some ATF drip, followed by slapping the pan back on and replacing some of that ATF.
It's also the only way to install any fixes or improvements such as mentioned by PNWYukon.

 

[NickTransmissions]

So I currently have 2004 4.8 Yukon that’s been my daily driver for the past 2 years I’d say, it finally reached the 180k mile point of its life span and it’s showing, my main concern has been the transmission as of late when I’m on the freeway 1st to 3rd seem to shift fine but 4th is when I feel it starts to struggle, I’ve checked the trans fluid it’s clean thankfully no shiny glitter and makes me wonder what could it be. If anybody can inform me I would much appreciate it

All things equal, falling out of 4th or no upshift to 4th is typical of failing 3/4 clutch pack, especially if there are no codes and no prior issues. Drop the pan and see what’s at the bottom. If the bottom is full of burnt clutch matter, put the pan back on with a few bolts and yank it for overhaul

 

[rockola1971]

So I currently have 2004 4.8 Yukon that’s been my daily driver for the past 2 years I’d say, it finally reached the 180k mile point of its life span and it’s showing, my main concern has been the transmission as of late when I’m on the freeway 1st to 3rd seem to shift fine but 4th is when I feel it starts to struggle, I’ve checked the trans fluid it’s clean thankfully no shiny glitter and makes me wonder what could it be. If anybody can inform me I would much appreciate it

What do you mean it struggles in 4th? Is it slipping (RPM's jump up in 4th when throttle is applied)? Any problems noticed in 2nd when moderate throttle is applied?