Whirring / Whining Noise 6L80

TM900 · December 5, 2022

On 11/15/2022 at 2:15 PM, movario said:

So, I replaced the valve body and still no difference.

BUT after replacing, I accidentially overfilled the transmission slightly. And the noise was almost always there and much louder. After I corrected the fluid level to the correct HOT level, the noise was back to normal.

So I suspect it has something to do with the fluid. Someone mentioned he changed the transmission oil to another manufacturer, and that solved the problem. I used Ravenol Oil (German Manufacturer) with Dexron VI specification. But maybe I should try AcDelco/GM Genuine?

movario did you replace only your valve body and not the TCU? I have the same sort of problem and wonder if it's the TCU/solenoid(s). I have a reman Dorman unit arriving soon but just want to try to understand everyone else's experiences before doing a bunch of work for nothing.

movario · December 5, 2022

I only replaced the valve body. I kinda hoped that worn checkballs were the reason. But that wasn't the case. I also thought about a new TCU, but those are expensive and would require programming (as you can't get them preprogrammend). And given that Chevys aren't sold where I live, I wanted to avoid that.

TM900 · December 19, 2022

On 12/5/2022 at 1:36 PM, movario said:

I only replaced the valve body. I kinda hoped that worn checkballs were the reason. But that wasn't the case. I also thought about a new TCU, but those are expensive and would require programming (as you can't get them preprogrammend). And given that Chevys aren't sold where I live, I wanted to avoid that.

Of course, always want to minimize part guessing!

Well I luckily had a friend who had a programmer, so I can actually even flash the TCU myself. Probably change that later this week and I'll let you know if the noise goes away. I'm also going to log before and after in HPTuners to see if there is any difference with the shift behaviors or shift speed.

DeeMorris · June 18, 2023

So, i was going to replace the torque converter but, it appears that is not the fix. I have a 2014 Silverado and the sound coming from the transmission is exactly like heard in the video. I did notice that replacing the fluid with Max- Life trans fluid helped a lot. Maybe a higher viscosity. Prior to that I used Castol Versatrans and the noise was much more apparent. This truck has been such a disapointment. Here's the short list:

Door Actuators (random locking unlocking problem) (replaced driver and passenger door actuators)

Water Pump (noise) (replaced)

Valve cover leaks (replaced gaskets)

Alternator (replaced)

A/c Compressor (replaced)

A/c Condenser (replaced)

Coolant Lines (heater) (replaced)

Oil Cooler Lines (replaced)

Rear End Noise (Rebuilt differential )

Hub bearings (replaced noisy)

Brake pad and rotor issues (numerous front and rear)

Excessive carbon on valves (walnut shell blasting)

Trailer Controller issue (Replaced switch)

Oil pan leaks (Resealed pan)

Rear Window inop (replaced rear window motor assembly)

Cooling fans randomly run at high speed (had to disconnect battery)

Thermostat stuck shut. (replaced)

Marcusvilla · September 12, 2023

Has anyone found this issue out yet? I have a 2018 GMC Sierra and I have the exact same noise at idle. It drives completely fine either on normal roads or going into highway speeds. No slips, not shutter or any sort but at idle does whine.

GMCustomerService · September 19, 2023

On 9/12/2023 at 10:42 AM, Marcusvilla said:

Has anyone found this issue out yet? I have a 2018 GMC Sierra and I have the exact same noise at idle. It drives completely fine either on normal roads or going into highway speeds. No slips, not shutter or any sort but at idle does whine.

This is certainly not what we like to hear, Marcusvilla. Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2018 GMC Sierra presenting a whirring noise at idle. To do so, please send an email to [email protected] with ATTN: Marcusvilla/GM Trucks in the subject line.

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Obie Matos · February 17

I have a 2015 suburbam with a 6L80 transmission and have been having issues with it for about 18 months, to sumarize at one point car just stoped and would not shift into any gear and i belived it was basicaly a transmission replacement job. However i managed to get the car going again and drove it home, barely made it. Once at home dropped the pan and replaced the fluid and filter. No probelms for about 1000 miles and it started to whine while shifting into 3rd to 4th gear and severely overheating also. This time i took it to a garage and i belive they replaced the transmission Pump and the car was running ok but the transmission was working like the overdrive was on sometimes always 1 gear up. This went on for about 9 months and now the winning is back and the transmission is misbehaving badly. I am going to replace fluid and like all the other times it will go away for a while and come back winning. I would say that the winning is related to oil degradation as is no longer overheating. The question is what is degrading the transmission fluid? Any comments would be helpful.