Drives for 1 city block

[EdTuck]

I have a 2017 GMC Yukon SLT 4 wheel drive 5.3 liter engine w/trailor package.
It starts right up, put in drive it goes. Get a block down the road and it's almost like it's in neutral. No reverse, put it in 4 wheel drive NOThIng.
Let it sit for 10 minutes and all works. Reverse, 4 wheel drive all good for a block.

Is it the transmission?
Would I be wasting my time to change filter and fluid?
Help

 

[swathdiver]

Sure seems like the transmission. In a few hours the sun will rise over Nevada and we'll hear from Nick when he gets a chance. @NickTransmissions

 

[NickTransmissions]

I have a 2017 GMC Yukon SLT 4 wheel drive 5.3 liter engine w/trailor package.
It starts right up, put in drive it goes. Get a block down the road and it's almost like it's in neutral. No reverse, put it in 4 wheel drive NOThIng.
Let it sit for 10 minutes and all works. Reverse, 4 wheel drive all good for a block.

Is it the transmission?
Would I be wasting my time to change filter and fluid?
Help

How many miles on that transmission?

What DTCs (if any) have been set/stored?

What does the fluid smell like on the dipstick?

Is fluid level correct?

Most likely it needs to be rebuilt, assuming fluid level is correct. Drop the pan to confirm/deny so you know - maybe the filter neck is cracked or filter is clogged....If you have a ton of burnt clutch material on the pan bottom, put the pan back on w/a few bolts and pull it for overhaul.

Visit my 6L80 Information thread for video instructions, tech resources, parts list and more - link is in my signature line.

 

[EdTuck]

How many miles on that transmission?

What DTCs (if any) have been set/stored?

What does the fluid smell like on the dipstick?

Is fluid level correct?

Most likely it needs to be rebuilt, assuming fluid level is correct. Drop the pan to confirm/deny so you know - maybe the filter neck is cracked or filter is clogged....If you have a ton of burnt clutch material on the pan bottom, put the pan back on w/a few bolts and pull it for overhaul.

Visit my 6L80 Information thread for video instructions, tech resources, parts list and more - link is in my signature line.

Thanks
I will take pan off tonight, unfortunately there is no dip stick.

 

[NickTransmissions]

Thanks
I will take pan off tonight, unfortunately there is no dip stick.

Gotcha....What codes (if any) does it have and how many miles o the transmission?

 

[EdTuck]

Gotcha....What codes (if any) does it have and how many miles o the transmission?

150k and u are right there is a dip stick, fluid level is a little high and it is a brownish read color. No code or no errors no engine light.

 

[EdTuck]

150k and u are right there is a dip stick, fluid level is a little high and it is a brownish read color. No code or no errors no engine light.

Transmission 7CLA

 

[NickTransmissions]

150k and u are right there is a dip stick, fluid level is a little high and it is a brownish read color. No code or no errors no engine light.

Yep, I believe most of the trucks had dip sticks, at least w/the six speeds. Let us know what you find in the pan...Don't forget to check the filter for cracks around the neck or anywhere else on the body. If you see a lot of burnt clutch matter, put the pan back on with a few bolts and yank it out for overhaul.