Six speed trans life expectancy

Grumpy Bear · February 22, 2019

48 minutes ago, KARNUT said:

No, the Jersey boys knew nothing but B&M. It sounded cool, we were young just learning.

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So...you sing? LOL

KARNUT · February 22, 2019

So...you sing? LOL

That would be wonderful, but no.

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IHscout · February 23, 2019

5 hours ago, Sierra Dan said:

Sorry to hear that Kooper.

Did you have an extended warranty?

Its a shame that there were no seemingly bad symptoms before it went belly up.

Or hopefully whomever you purchased the truck from was not hiding something.

Unfortunately no extended warranty. I bought it off a lot so I guess it was all on me to spot it. Having driven my wife’s 2015 suburban I thought I had a good feel for these transmissions but obvisously not. There was about three days of a tale which I had incorrectly determined to be the TC locking and unlocking on the highway that others have noted. I was actually headed to the dealer for a trans flush and inspection when it went out. I am stepping out of a twenty year old Powerstroke so going back to a gasoline half ton has been a learning experience.

I must give the car salesman some credit he did chip in a grand to help which he didn’t have to do.

Cpl_Punishment · February 23, 2019

On 20/02/2019 at 2:19 PM, Silverado-Hareek said:

So far knock on wood, my transmission is ok and I have about 67,000 miles. However, two people I know have had issues with their transmission. One has a 2016 Tahoe with 130,000 miles just replaced the transmission. The other has a 2014 Silverado with the same 6 speed transmission and they're currently fighting with the dealer to get it fixed. It started with a temperature sensor issue that the dealer supposedly fixed but they didn't actually fix it. The problem was first reported under warranty but now the truck is out of warranty so it's a battle. I'm keeping an eye on mine. It's 5 years old this month. My 2007 silverado had the tranny go out at 80,000 miles and then I was facing an engine replacement at around 97,000 miles which is when I unloaded it and bought my 2014. If this 2014 truck doesn't make it to at least 150,000 miles without a single major transmission or engine issue, I'm switching to Toyota. I'm tired of watching every Toyota owner around me drive 200+ thousand miles with their vehicles and never do any major work while I'm always shelling out thousands of dollars in driveline repairs. At some point, it just becomes stupid on my part financially to keep buying Chevrolet.

I would buy a Tundra if they drove smaller and had more payload and towing capacity and better fuel economy.

Cpl_Punishment · February 23, 2019

On 21/02/2019 at 8:01 AM, IHscout said:

Several good points made here. I guess it all comes down to buying new versus used in a way. There is always a risk when you don’t know the history of something.

On a a side note the recommended service intervals in the manual do not show a transmission fluid change until 95,700 miles. Dealer recommended every 50k as do several members of this forum. Why? And let’s go ahead and weed out the obvious, a $300 dealer flush and fill is cheaper than $4,000 new tranny.

Definitely not so the stealership can charge you an extra $300 every 50k...

Brian Burg · February 23, 2019

When a dealership flushes the transmission they don't drop your pan clean your Magnet or put a new filter in so I would highly recommend if you can't do it yourself take it to the transmission shop and have them dropped a pan change the filter and flush the cooler lines and there ain't no way anybody should charge you $300 that's just absurd and then another thing with these Transmissions is they run very hot so if it's out of warranty there isn't it transmission thermostat usually accept external with their training lines attached to it so I recommend because I've done this is disconnect and bring out the thermostat housing pulling thermostat the internals you'll see at the bottom of a hole what you do is your run a half inch tap 4 threads and you put a flush mount brass plug what this will do is continuously cycle your transmission fluid and it should keep it under a hundred eighty degrees I was also recommended to put a separate trans cooler and delete the one on the the radiator because it doesn't cool for crap I'm old school when I transmission gets close to 200 that's too hot for me

flyingfool · February 24, 2019

tranny shifts firmer at 120-130 degrees vs 210-230 on the highway,

my 2012 2500 sierra HD is stock, with 6 spd, truck has massive trans cooler from factory, it run 120 degrees all its life, pulling toy hauler it hits 122 degrees...

Grumpy Bear · February 24, 2019

1 hour ago, flyingfool said:

tranny shifts firmer at 120-130 degrees vs 210-230 on the highway,

my 2012 2500 sierra HD is stock, with 6 spd, truck has massive trans cooler from factory, it run 120 degrees all its life, pulling toy hauler it hits 122 degrees...

Yes, wont hurt it a bit.

Silverado-Hareek · March 5, 2019

On 2/23/2019 at 9:59 AM, Cpl_Punishment said:

I would buy a Tundra if they drove smaller and had more payload and towing capacity and better fuel economy.

Do they not have more? For some reason I thought they were an "inbetween" truck in that they were more capable than 1500's/F150's but not as capable as 2500's/F250's. At any rate, I'm not throwing in the towel just yet. I bought my 2014 Silverado with the hope that the oil consumption problem had been worked out and based on the fact that the 6 speed transmission had been in service for a good while. We'll see what happens. I'm continuing to take good care of this thing. I'm not naive enough to think that Toyota's won't have any problems at all. But everyone I know with one is driving 150,000+ miles and they aren't doing anything other than routine maintenance. Meanwhile, everyone I know with a post 2006 GM is having some form of major engine or transmission problem. They just don't build them like they used to.....that old Vortec engine was a damn beast. My dad's '04 suburban is still going strong with nearly zero issues.

On 2/22/2019 at 2:22 PM, 00pooterSS said:

Crazy you had all those issues. Sounds like just pure bad luck. I've had excellent luck really. I've done things to motors and transmissions that most say cannot be done and they took it like a champ for years..

Burning oil is becoming increasingly common with newer valvetrain tech and it sucks, but I'm not gonna replace an engine over it. Especially when the lower mileage ones are doing it too. However I'll say a quart every 3k or so isn't terrible at all. Almost every car I ever had has used around that much..

Agreed it was some terrible luck. In hindsight, I maybe could have kept driving it and adding oil. But I was reading horror stories online about people replacing engines to the tune of $7k with minimal GM assistance. I decided to bail. Right or wrong, I gambled. We'll see how this 2014 holds up. Just hit 68,000 miles and I've babied this one. I've even only used 89 octane top tier fuel since about 14,000 miles. Only synthetic oil, all fluids have been changed at least once. I have an oil catch can installed. If this thing doesn't make it to 150,000 miles without major work I'm quitting haha

Grumpy Bear · March 5, 2019

On ‎2‎/‎22‎/‎2019 at 6:21 AM, CyaDwnthaRd said:

I drive a 2016 5.3 2wd, 3:42. Its a great truck, absolutely no issues at 67K. Well maintained and I stay on top of recommended fluid changes.

In south Texas the temperature in summer driving concerns me as far as long term trans durability. My gut feeling and common sense tells me to run cooler and eliminate the thermostat and bring the operational temps below the 195 degrees. Am I missing something?

No, your on target.

And I understand the synthetic fluid improvements and its ability to handle heat. But again, One of my questions, did Chevy program the TCM to alter shift points based on temp? And, by eliminating the thermostat will that in itself be detrimental in the long run?

No. They didn't even have one until 2014.

On ‎2‎/‎22‎/‎2019 at 6:21 AM, CyaDwnthaRd said:

I've received mixed advice from several respected mechanics regarding the removal of the 6l80 thermostat.

Don't doubt that a bit.

On ‎2‎/‎22‎/‎2019 at 6:21 AM, CyaDwnthaRd said:

And along that advice, the Dealers service writer advised against adding an auxiliary Transmission air cooler.

And, another thought concerning operational cool temperatures. On first start up, considering the 10 second to 3 minutes before driving the trans temp is ambient. So how is the concern of operation during low temperature a concern to the internals?

Advice from superior knowledge, PLEASE.

It isn't.

Your common sense isn't failing you. Run a reasonable temperature. 120 F to 180 F. If that takes a cooler and a thermostat delete or installation of an aftermarket with a lower set point then that's what it takes.

swathdiver · March 5, 2019

Most problems with the 6L80 is that the TECM/TCM/TECHM just needs rebuilding, not the trans itself.

These things are designed to run hot.

I wrote about temps as it relates to the GMT900s (post #290):

https://www.tahoeyukonforum.com/threads/useless-information.97483/page-29

With the weather warming up there's been talk of transmission temperatures and some fellas have been adding and or upgrading external coolers to keep the temperatures in line.

The 6L80s normal operating temperature is between 160 and 200 degrees. This corresponds with the HOT check on the dipstick when checking the fluid level. Cold check temperatures are between 80 and 90 degrees and also have a corresponding mark on the dipstick; mine anyway.

The temperature range for the Service Fast Learn Adapts procedure is 158-212 degrees.

If the transmission's temperature reaches 266 degrees for 5 seconds the "Transmission Hot Idle Engine" warning will display on the DIC.

Code P0218 (Transmission Fluid Overtemperature) will set if the fluid is greater than 270 degrees for one minute. On a side note, the shop manual says trailer towing should occur in D4 to ensure the cooling system functions normally.

The Flash Point for AC Delco's Dexron VI fluid is 401 degrees.

There is a transmission oil life monitor within the Transmission Control Module and is visible and able to be reset with the Tech2. I reckon that it is also based on engine revolutions and transmission temperature, similar to the Engine Oil Life System.

Remember, these trucks were literally designed to tow fully loaded across Death Valley.

Cpl_Punishment · March 5, 2019

11 hours ago, Silverado-Hareek said:

Do they not have more? For some reason I thought they were an "inbetween" truck in that they were more capable than 1500's/F150's but not as capable as 2500's/F250's.

You're thinking of the Nissan Titan XD.

CyaDwnthaRd · March 5, 2019

These topics are a great resource. I appreciate the feedback and posts from those subscribers submitting ideas and advice.

The posts in this topic reminded me of the correlation between MANUFACTURERS RECOMENDED operational temperature, ACTUAL loaded towing temperature spikes and how the upper protection limits of these lubricants can and ARE diminished greatly.

In my case, being in South Texas the predominant weather is HOT. Very Hot in the summer when I would normally vacation with the RV. So on my sled I will do the free upgrades first and proceed to another step if needed to lower the overall engine oil and transmission fluid.

I'm going to do the transmission delete and lower the engine thermostat to the gm 197. I plan to adjust the fan by tune once these modifications are complete.

Enjoy the Spring. Be safe out there...

Bobaloo22 · March 7, 2019

Here's a related issue here in Virginia. My trans temp has not been over 150 degrees since last September, so no flow to cooler. I have done two drain and fills during this time and I just realized that all of the fluid in the cooler and lines have sat there all of these months and not mixed with the fluid in the trans and torque converter. Eliminating the t stat will allow the fluid to "mix" during cold weather and has got to be better for the tranny. Also no shifting issues at all for the last 5 months, so why do these trans "need" to be so hot when they cannot get there in the winter.

Bob

Grumpy Bear · March 7, 2019

I've put up this chart before. NOITCE this is FLUID LIFE not transmission life? That's a question, not a statement.

Notice in swathdivers comments below: (excerpt)

The 6L80s normal operating temperature is between 160 and 200 degrees.

The temperature range for the Service Fast Learn Adapts procedure is 158-212 degrees.

If the transmission's temperature reaches 266 degrees for 5 seconds the "Transmission Hot Idle Engine" warning will display on the DIC.

Code P0218 (Transmission Fluid Overtemperature) will set if the fluid is greater than 270 degrees for one minute.

Now run your finger across the chart to the 50K maker and up to temperature. 220F and what happens at that temperature? Varnish formation. Thus the OEM normal 160 to 200 F normal operating range (staying under that temperature). This should end to the idea that synthetic fluids were not considered when the chart was prepared. (The claim is the factory fluid is a synthetic, right).

It explains why 45K is the recommended ATF fluid change interval for severe service. At the factory preset alarm temperatures everybody and their brother is claiming SYNTHETIC FLUIDS can handle that all day long.

Below 175F fluid temperature life is?????????

The only thing that happens when the temperature is between 100 F and 175 is it uses a bit more fuel and you have allot of cushion. That is not a bad thing. Pepper can still get well over the EPA MGP numbers at 120 F. It does better at 145 F and I see no improvement above that temperature in mileage. Just say' n.