21’ Tahoe Tranny Fluid Flush vs Tranny fluid change and change filter

[Jm08]

I need advice on my 2021 Tahoe LT with the 10speed tranny, Tranny Fluid Flush or Tranny Fluid Change and changing the filter? Currently it has 83,000 miles on it. The maintenance schedule under "Severe" conditions suggests changing both the transmission fluid and the filter, but for "Normal" driving conditions, it doesn't mention anything about changing or flushing the transmission fluid. I don’t tow and mostly do city/highway driving.

I’ve been quoted $300 for a simple transmission fluid flush, but if I opt for a full fluid change with a new gasket and filter, it’ll cost me double that. What is recommend? Is it overkill to go for the full service, or should I stick with just the simple flush? I want to make sure my transmission stays in good shape. I bought my Tahoe with 50,000 miles on it, so I’m not sure if the fluid was ever changed before.

Thank you everyone in advance

 

[WalleyeMikeIII]

I would do it at 2x the "Severe" interval or less. I believe you need to do the filter too...so at that point, since the pan has to come off, not sure the benefit of the flush in addition, other than burning some additional transmission fluid.

Note, if you have 4WD, I highly recommend doing the transfer case as well, and the front and rear diff. All that stuff is cheap compared to buying new driveline components.

 

[iamlegion]

I would do it at 2x the "Severe" interval or less. I believe you need to do the filter too...so at that point, since the pan has to come off, not sure the benefit of the flush in addition, other than burning some additional transmission fluid.

Note, if you have 4WD, I highly recommend doing the transfer case as well, and the front and rear diff. All that stuff is cheap compared to buying new driveline components.

This. It’s hard for some folks to wrap their heads around, but unless you’re doing severe workloads your chances of causing a problem are generally higher than solving a problem that is yet to exist messing with it.

Curious was a dealer that quoted that? Some I know of will even avoid doing it at all unless you’re exhibiting problems.

 

[Jm08]

This. It’s hard for some folks to wrap their heads around, but unless you’re doing severe workloads your chances of causing a problem are generally higher than solving a problem that is yet to exist messing with it.

Curious was a dealer that quoted that? Some I know of will even avoid doing it at all unless you’re exhibiting

The dealership said their standard procedure is to do a flush, but my mechanic could do both a flush or a full fluid change with filter. I wanted to find out which option is more beneficial since I'm not sure if the transmission fluid was flushed at 50,000 miles.

 

[blondie70]

I have never had a transmission flushed. Have dropped pan and changed filter then refilled with about 7 qts. of oil. done.

 

[Geotrash]

I need advice on my 2021 Tahoe LT with the 10speed tranny, Tranny Fluid Flush or Tranny Fluid Change and changing the filter? Currently it has 83,000 miles on it. The maintenance schedule under "Severe" conditions suggests changing both the transmission fluid and the filter, but for "Normal" driving conditions, it doesn't mention anything about changing or flushing the transmission fluid. I don’t tow and mostly do city/highway driving.

I’ve been quoted $300 for a simple transmission fluid flush, but if I opt for a full fluid change with a new gasket and filter, it’ll cost me double that. What is recommend? Is it overkill to go for the full service, or should I stick with just the simple flush? I want to make sure my transmission stays in good shape. I bought my Tahoe with 50,000 miles on it, so I’m not sure if the fluid was ever changed before.

Thank you everyone in advance

"Flush" is a bit of a misnomer. It's the same process for all modern transmissions at most quicklube shops and dealers. They disconnect the cooler lines, connect them to a fluid exchange machine, start the engine and let the transmission's pump circulate the fluid through the machine. Sometimes at this point, they will add a detergent and let the fluid circulate through the machine's contaminant filter loop for 3-5 minutes. When the tech is ready, they change the machine mode to capture the old fluid while drawing the new fluid in, replacing it with the correct quantity of new fluid. Then they do a level check, reconnect the cooler lines, and you're on your way. I've always had my transmissions done this way every 20-30K (depending on towing duty) and never had a problem. Every 40-60K, I drop the pan and replace the filter instead of having the fluid fully exchanged.

Knock on wood, I haven't had a transmission fail that's been maintained this way. I did have a valve body fail, but it was a common issue with that transmission, and an updated valve body fixed the issue. I credit this process for keeping a 4L30E (usually good for no more than 150K) going for 300K with no issues.

 

[DontTaseMeBro]

I have never had a transmission flushed. Have dropped pan and changed filter then refilled with about 7 qts. of oil. done.

This is the way. You won’t get 100% of the fluid out but it will be the majority. I’ve actually heard that flushing a transmission is not a good thing.

 

[ivin74]

I have never done a tranny flush, I always go with the total change out including the filter and have been never experienced transmission failures on any of my vehicles. In my fleet I have 2 high mileage vehicles one is a Honda with 155k miles the other is a yukon with 197k. I can take either one across the US and don't have to worry about getting stranded.

 

[fors43]

Just had highly rated transmission shop quote $800 for full trans service including filter. 3 hours labor plus parts was $800. 2019 Yukon 5.3 at 80k miles. Decided to do it, i guess maybe overkill based on what i'm reading here

 

[fondupot]

Just had highly rated transmission shop quote $800 for full trans service including filter. 3 hours labor plus parts was $800. 2019 Yukon 5.3 at 80k miles. Decided to do it, i guess maybe overkill based on what i'm reading here

Pricey. I just had my 10 speed in my 2021 Yukon serviced for $250. Just pan service and filter though. I think I'm going to do 30k intervals on my Yukon.

 

[ivin74]

Pricey. I just had my 10 speed in my 2021 Yukon serviced for $250. Just pan service and filter though. I think I'm going to do 30k intervals on my Yukon.

Thats cheap, around here it's $500.

You sure it wasn't just a flush? Oem oil and filter it self is $200 bucks.

 

[fondupot]

Thats cheap, around here it's $500.

You sure it wasn't just a flush? Oem oil and filter it self is $200 bucks.

Positive. I asked. They drop the pan. Change the filter. And top off with fresh fluid.

 

[jerry455]

I am putting a drain plug in mine. I tried to suck some out the other day and only got less than 2 quarts. I guess that side plug is not a straight shot into the pan. It is amazing that the directions tell you to shake up the new fluid before putting them in. I will probably wait until the spring to drop the pan. I have seen some videos on doing this. One of them used a pry bar on the exhaust crossover in stead of dropping it and sneaking the pan out.

 

[fr8bil]

Picked up this one-owner 2018 Yukon Denali with the 6.2 and 10 spd. with 132k on it last Feb. but it was super clean and well cared for and very "tight". One thing I was unable to determine with CarFAX was to find any record of a tranny service so took it over to the nearby GMC dealer I've done business with for 14 years. Service advisor wildly under-quoted their tranny-flush price by $200 and told me the 10 spd. had an external filter. Once the service was complete and I got done bitching them out for the price mis-quote, they said this vehicle's tranny did NOT have the external, OEM filter on it. No idea if that was added later in the 2018 model year or if the guy had no idea what he was talking about.

 

[WalleyeMikeIII]

https://static.nhtsa.gov/odi/tsbs/2024/MC-11011205-0001.pdf

That document should answer the question about Flush vs. Drop Pan, change filter, refill.

 

[jfoj]

The term "Flush" with regard to either hydralic power steering systems or automatic transmissions is typically a "Fluid Exchange". Usually there are no added chemicals or "flush" additives. A low pressure pump usually pushes new, fresh fluid though the sytem to "Exchange" the old, dirty fluid. With regard to automatic transmissions, there tends to be a lot of old dirty fluid stored in the torque converter, cooling lines and radiator/transmission cooler. You could expect a fluid "Flush/Fluid Exchange" on an automatic transmisson to require 2 times or even a greater amount of transmission fluid that just dropping the transmisson pan for a fluid service.

There are no negative effects of a properly performed automatic transmission "Flush/Fluid Exchange" assuming the proper transmission fluid is used and the level is properly set. Ideally a fluid exchange and a pan drop with a new filter is incorporated as well. Often the "Flush/Fluid Exchange" can be performed while the transmisson pan is off.

The majority of the stories on the Internet where people claim they had an automatic transmission "Flush/Fluid Exchange" then had a catastrophic transmission failure in short order is usually due to the vehicle owner not maintaining the transmission, realizing there may be a problem and then expecting a fluid service to correct hard part problems that were enevidible. New fluid that is of the correct type and set to a proper level will not cause premature failure of an automatic transmission. Usually the pin on the grenage has been pulled long before the fluid service is attempted in a last ditch effort to solve a much more major problem!

 

[jerry455]

I wouldn't hesitate getting a fluid exchange at a GM dealer. When I had my 2018 Colorado with the 8 speed transmission, that was the fix for the shudder. Changing "black label" Mobil fluid for "blue label" Mobil fluid. What a difference. Since the forecast, tomorrow for the metro Detroit area is in the mid 50's and early rain, I will drop the pan and change filter and fluid on my 2021 Suburban 10 spd. I may even do plugs and wires.

 

[jerry455]

Well, I did the fluid and filter today. It is really tight prying down the exhaust to get clearance for the pan. I also loosened the trans mount to get a little more clearance. The exhaust would bottom out on the trans crossmember. The fluid didn't look too bad, obviously longer than I would have done it, 79,000. Put filter and then pan on, filled it with 5 quarts, that's when it was coming back out and started it. Tried to shift and it would not, kept telling me, can't complete shift problem with trans. Set a check engine light. Stopped and started it 2 more times and then it started working. I had OnStar check the code for me, P0700 and P18AB. Not sure what they are exactly, will have to look in Service Information, but remote start works, which surprises me. One of these days I am going to find the engineer who did this trans and give them a piece of my mind. Stupid way to fill and check trans fluid.

 

[RST Dana]

So, a local Caddy dealer in Cincinnati service writers tell everyone that asks, 10 speed Esky or Tahoe transmissions have “lifetime” fluid. I couldn’t believe it the first time I heard it. Called back a week later and a different person repeated the same crap. I wonder how GM would react to a warranty claim for failure with “no” trans fluid service history?

 

[jfoj]

Well, I did the fluid and filter today. It is really tight prying down the exhaust to get clearance for the pan. I also loosened the trans mount to get a little more clearance. The exhaust would bottom out on the trans crossmember. The fluid didn't look too bad, obviously longer than I would have done it, 79,000. Put filter and then pan on, filled it with 5 quarts, that's when it was coming back out and started it. Tried to shift and it would not, kept telling me, can't complete shift problem with trans. Set a check engine light. Stopped and started it 2 more times and then it started working. I had OnStar check the code for me, P0700 and P18AB. Not sure what they are exactly, will have to look in Service Information, but remote start works, which surprises me. One of these days I am going to find the engineer who did this trans and give them a piece of my mind. Stupid way to fill and check trans fluid.

I have not even checked for a transmission dipstick on my truck, however, many newer vehicles have no automatic transmission dipstick. In this case, you MUST verify and top fluid off with the engine running and the vehicle in Park!!! If there is no automatic transmission dipstick on your vehicle and you only filled the unit while the engine was off and you have not checked and topped it off with the engine running, your transmission will likely be 2-3 quarts low on fluid.