Six speed trans life expectancy

[dieselfan1]

On 2/17/2019 at 10:04 PM, Grumpy Bear said:

Three ways to destroy a transmission. Heat. Abuse. Neglect. It only has two failure modes. Mechanical failure or wear. Wear is directly related to heat. The other by load beyond design or defect in materials or workmanship. Change the fluid. Keep it cool. Control the load. It is absolutely within your control if it isn't flawed. Few are flawed.

 

I'm sure the ones that fail are far and few between.

So a few fail  here and there and we get these threads like this .....

Life expectancy? C'mon man.

The transmission shops you talked to are on drugs. So they will all fail at 80,000 - 100,000 miles? I highly doubt it.

I've never had a transmission failure or problem with transmission on any of the 16 Chevy trucks I've  owned since 1980. My last six speed Silverado had 215,000 miles on it and never skipped a beat and I towed with it probably over half of those miles. I changed the fluid every 40,000- 50,000 miles like you are supposed to.

Life expectancy. Jeezus.

To the OP I'll bet the truck you bought with 95,000 miles on it never had the fluid changed.

[Silverado-Hareek]

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.

[diyer2]

On 2/16/2019 at 5:21 PM, Grumpy Bear said:

There use to be this kid in a town I grew up in I saw on the 'mile' but never really knew except that he wasn't shy about the use of the loud pedal, power braking clouds and neutral drops abundantly.  

 

He stops by my shop one day asking about a C6 I'd just freshened and put on the board. He want's to know what warranty I am willing to provide and wants me to take his check. None and no. Cash and to the end of the drive I tell him. "I've seen you drive". He tells me I must be a crap builder. Whatever. 

 

Look, a box last as long as it last and that is subject to the use and maintenance it gets. Yea, yea, yea, everyone makes a lemon and some, granted have weakness it doesn't take much to exploit into a major problem. They ALL do. Treated right the 6L80E and 6L90E are good boxes. Treated other, you get other. 

 

Agree

Simple, maintain and don't abuse.

[diyer2]

12 minutes ago, 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.

You're doing something wrong IMO.

 

[Silverado-Hareek]

22 minutes ago, diyer2 said:

You're doing something wrong IMO.

 

Yeah apparently taking too good of care of a vehicle is bad for it.....

[00pooterSS]

3 hours ago, Grumpy Bear said:

There are two You Tube videos on it but no writeup I can link you to. That said....

 

What you are calling the adaptor block is actually the thermostat. 

 

 

See that snap ring in the top? Push down on the cap and remove the snap ring. The cap and the internals are now free to be removed. Under the cap is a spring and thimble under that is a 'pill'. The actual working part. Turn that pill upside down and reassemble.

 

Another method has you removing the guts completely. If you chose that method you have to drill and tap a pipe plug into the area the pill rest upon to isolate the inlet from the outlet. I used the first method. I like the idea the spring remains in place assuring the cap is well seated against the snap ring and leak free.

 

If you have a bench vise and a socket with an OD a bit smaller that the Snap Rings ID and let the vise do the heavy work this goes much smoother. It is a stiff spring. Apart isn't a problem. Together takes three hands.

 

Important note. That top line is the output of the pump and the lower line the return from the cooler assembly. The factory thermostat DOES NOT have a minimum flow bypass. It is fully internally bypassed when under it's 195 F set point. When under the trip temperature the outlet is fully 'short circuited to the return and removing either line will thus make it appear as if the lower line is the output. It's important if in the future you decide to add a filter or second cooler or change fluid using the internal pump. I  wouldn't but there are those that see that as fine. 

 

Anyway, hope that is useful. At least if you find the video's it will make more sense to you. 

 

 

 

 

VERY helpful. Thank you!

[flyingfool]

the t-stat delete was my first mod, running 200 degrees trans temp is just wrong! now I'm cruising 130 degrees all day, its very easy to do, any old fart cant do it!

[diyer2]

16 hours ago, Silverado-Hareek said:

Yeah apparently taking too good of care of a vehicle is bad for it.....

So you're saying you got a bad trans and engine?

Possible.

 

[IHscout]

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. 

[flyingfool]

they are using a new synthetic fluid that has even more durability than previous Dextron3 fluid we've been running for decades. the new fluid can take more heat, and hold more dirt in suspension, etc, etc...

 

since the early 1990's, newer transmission in German cars have the ability to cut ignition between shifts, so as not to cause clutch slip between shifts and damage the clutches under heavy loads. this tech might have made it into the new trucks by now, this will increase lifespans dramatically..

[GMC Sierra fan]

I have a 2011 Sierra and it has 120 kilometers owned since new and tow a 27 foot 5th wheel about 7700lbs empty  max towing is 9800 so I'm real close to max when loaded for a trip changed fluid at 85k and so far so good other than it gets reluctant to gear up when I'm driving her hard pedal all the way down takes about 5sec to 10 to change when I get off it 

[CyaDwnthaRd]

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

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.

[00pooterSS]

12 hours ago, flyingfool said:

they are using a new synthetic fluid that has even more durability than previous Dextron3 fluid we've been running for decades. the new fluid can take more heat, and hold more dirt in suspension, etc, etc...

 

since the early 1990's, newer transmission in German cars have the ability to cut ignition between shifts, so as not to cause clutch slip between shifts and damage the clutches under heavy loads. this tech might have made it into the new trucks by now, this will increase lifespans dramatically..

 

GM has had it for about 20 years, they call it Torque Management. I didn't notice it at all in my 04 truck and not positive they actually used it on that specific truck, but it is for sure on my 14. The 6L80/90 and 8L90 trucks (and cars) 100% use it. I can hear it through my exhaust and feel it during shifts. It is one of the key things that has allowed bone stock transmissions to hold 1k or more hp these days. 

 

Supposedly it was on 4th gen F bodies too, but I didn't notice it on mine, it may have been tuned out though not sure. 

Edited February 22, 2019 by 00pooterSS

[00pooterSS]

On 2/20/2019 at 3:57 PM, Silverado-Hareek said:

Yeah apparently taking too good of care of a vehicle is bad for it.....

 

 

Something is up because that is the polar opposite of what I have experienced with my vehicles and most of my customers. I've been a tech for 20 years and I have owned GM vehicles (primarily LS and LT vehicles with 4L60 and 6L80 transmmissions) since 06. 

 

I have had friends that somehow burned up motors and transmissions at low mileages and there has always been a reason. There are cases where bad things just happen. But you've had several things happen that aren't typical. Really sucks.

 

One of my friends was on his 3rd 4L60 trans in his avalanche by 99k miles. I knew him well, he was the type that drove like a grandpa everywhere and I bet he didn't go past 20% throttle 99% of the time. Yet he's blowing through transmissions before they are even due for fluid changes. After nearly a couple of years of me wondering why I was riding with him one day pulling his boat, we're going up a half mile long hill pulling a boat and the truck is struggling it's ass off and he's just driving along. I asked are you "gonna down shift or at least put it in tow mode?", he said why I never have before...

 

Meanwhile I beat the living dog shit out of my truck, had it tuned and the rev limiter raised to 6500 rpm and I just hammered it everywhere all the time, when I sold it with 191k miles the trans was still mint. Same with my camaro. Had it tuned, bolt ons, big 3800 stall, trans went 190k being just beat the **** up every single day. Some transmissions don't like grandpa driving, a lot of them slip the clutches at light throttle and it wears them out fast. Talked to a builder about this and he said his brother drives like a 90 year old woman, uses only redline trans fluid, and goes through transmissions.

 

If you keep the fluid changed in the engine and trans,  keep the temps right, and keep them from slipping a lot, they will last a long time. 

 

All that being said, sounds like you've had some bad luck. 

[Grumpy Bear]

On ‎2‎/‎21‎/‎2019 at 9:01 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. 

I have 86K on my truck and done four drop and fill services. First at 50K. Excessive if I were just doing the dump and fill but I'm also changing fluid type to Group IV/V. Factory fill is a Group III. At 50K it was already degrading. On the first hit we also changed the filter and deleted the thermostat. On the next swapped to a PML 8 quart pan. Now I can do it at home. Heat, that is the bottom line. She was running 225-250 F in the summer with no load. Now....150 F ish summer. 130 F winter. Takes about six drop and fills to exchange over 90% of the fluid. Takes over a barrel to do it with a pressure rig.