2017 Tahoe Trans - Noise / Filter?

[Iamchris]

Hey all! I’m looking for a little guidance on my Tahoe.
My 2017 5.3 started making a noise recently, at first I thought it sounded a bit like a power steering pump going low or bad. Kind of a squeal. I narrowed it down to the transmission and decided to not freeze, so I brought it to a local general mechanic.
They confirmed that it was the transmission and pulled the pan under the suspicion that the filter was off. They responded today and said that it wasn’t and that the transmission was “shot”. That was the receptionist, she couldn’t answer any more questions and I won’t be able to talk to the mechanic till Monday.
I’ve been searching and reading. The Tahoe was driven to the shop, it exhibited no change in driving characteristics. No hard or slow shifts are noticeable.
I’ve seen that some people have found cracked filters or had clogged filters and I’m wondering if this is likely, given that the transmission isn’t acting up.
They offered to change the transmission, but I’ve instructed them to put it back together. I’m going to check with the dealership next.
I’m looking for advice with anyone who may have experience in diagnosing the problem, and advice in repair. Is it worth the shot to have the shop drop a new filter and fluid in when they reassemble, as in is it reasonable that it could be that? Are these transmissions replaced rather than repaired? Is a new transmission from Chevy my best option?
I’m not happy to hear that the transmissions on these are so prone to failure. It I am looking at getting it back to serviceable. It only has 90k miles and we own it outright.
Thanks in advance.

 

[NickTransmissions]

Hey all! I’m looking for a little guidance on my Tahoe.

What transmission do you have? Im assuming a 6L80 but will let you comfirm/deny...

Noise coming from the trans is most likely planetary carrier, especially if it's a whining, grinding or growling noise. A knocking or rattling noise can be pump whine. Either means the trans must come out for overhaul.

 

[Iamchris]

What transmission do you have? Im assuming a 6L80 but will let you comfirm/deny...

Noise coming from the trans is most likely planetary carrier, especially if it's a whining, grinding or growling noise. A knocking or rattling noise can be pump whine. Either means the trans must come out for overhaul.

Thanks for the response! I assumed a 6L80 also. What is the best way to tell?
The noise is kind of like a swooshing sound. I don’t have the truck until Monday but I can get a video of it once I do.
So you answered my question a bit by saying it needs to come out for an overhaul. The shop jumped straight away to replacement at $5500. Ofc I guess if it is the different between a 3k rebuild with no warranty and a $5500 replacement with warranty I’d probably consider the replacement.

 

[NickTransmissions]

Thanks for the response! I assumed a 6L80 also. What is the best way to tell?
The noise is kind of like a swooshing sound. I don’t have the truck until Monday but I can get a video of it once I do.
So you answered my question a bit by saying it needs to come out for an overhaul. The shop jumped straight away to replacement at $5500. Ofc I guess if it is the different between a 3k rebuild with no warranty and a $5500 replacement with warranty I’d probably consider the replacement.

RPO Codes, they may be in the glove box on a big sticker...If so, look for the code "MYC" - that's GM's regular production option (RPO) code for the 6L80. 3k for a rebuild would constitute flat rate work, meaning the shop is only replacing the direct cause of the failure without doing anything else about all the other worn parts and components in the unit.

Ask the shop where that replacement transmission comes from...If it's a GM newly manufactured transmission, it will have a 3 yr/100k warranty, come with all the updates GM put into those transmissions over the years and can be serviced or warrantied at any GM dealership nationwide. Also ask what converter comes with it - should be an upgraded converter with a thicker converter clutch, at minimum.

If the unit is coming from Jasper, LKQ, Moveras or any other aftermarket reman, you're stuck dealing with that shop to have any warranty repair done to it..I believe Jasper at least pays the shop to r/r one of their units if it has to come back out again.

If you do have a 6L80, visit my 6L80 Information Thread for more details on these transmissions - link is in my signature line.