Drives for 1 city block

EdTuck said:

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

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NickTransmissions said:

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.

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EdTuck said:

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

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NickTransmissions said:

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

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EdTuck said:

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.

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EdTuck said:

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.

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