6L80E T Stat

Drivetrain discussion including Transmission, Differential, Driveshaft, and related items.
9C1fanatic
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Joined: Tue Dec 30, 2014 8:58 pm
Location: Texas Hill Country

6L80E T Stat

Post by 9C1fanatic »

Hey guys its been awhile. Been a few hard years but I'm back and life is good. I wanted to know if any of you guys knew if the 6L80E in our cars has a transmission fluid thermostat like the K2XX trucks do with the same transmission? I don't think the GMT 900 trucks with the 6L80E had them so Im not sure about the Caprice since it kind of spans part of both Generations of the GM trucks Im talking about. I would like to know for future reference as well as transmission fluid changing procedures which Im about to undertake now that Im nudging up to 40,000 miles.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
smwalker
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Re: 6L80E T Stat

Post by smwalker »

No mention if any thermostat in the service manual with regard to the trans. And the cooler is just straight pipes into the case so never seen a thermostat like in the trucks.
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
9C1fanatic
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Re: 6L80E T Stat

Post by 9C1fanatic »

Thanks!!
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
Oldblue68chevy
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Joined: Sun Aug 20, 2017 7:06 pm

Re: 6L80E T Stat

Post by Oldblue68chevy »

There is a temp sensor that is used to determine fluid level. You have to go into engineering mode on the dash and it is one of the options displayed. Unfortunately it isnt one of the display options while driving around unless you put it into engineering mode every time you start up the car.
2011 PPV 9C3
Sanford
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Location: Texas Gulf Coast

Re: 6L80E T Stat

Post by Sanford »

The parts list shows a bypass valve at the cooler, which I am guessing is acting like a thermostat. You don't want to overcool the fluid in cold weather.

David
9C1fanatic
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Re: 6L80E T Stat

Post by 9C1fanatic »

That engineering mode only works on 2011-2013 cars right?

I'm failing to understand how automatic transmissions have survived all these years in cold climates without a thermostat. Seems just another failure point to me. Are you seeing this on the external cooler mounted up at the very front? On the trucks, the t state is right at the transmission where the lines go in.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
CrashTestDummy
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Re: 6L80E T Stat

Post by CrashTestDummy »

Garner!! Long time no see. Good to see you back on the list.
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
And some others
Do YOU have my SPID?
9C1fanatic
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Joined: Tue Dec 30, 2014 8:58 pm
Location: Texas Hill Country

Re: 6L80E T Stat

Post by 9C1fanatic »

Thanks. Still have my caprice. Still have my city caprice. Life got my busy there for a while. Just paid off the Caprice and looking forward to owning it free and clear! Great to hear from ya.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
s/c'd cav
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Location: PHOENIX AZ

Re: 6L80E T Stat

Post by s/c'd cav »

yes they have a thermostatic bypass at the trans cooler , it loops the trans fluid back to the trans by passing the cooler , until its up to temp
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kevink
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Re: 6L80E T Stat

Post by kevink »

s/c'd cav wrote: Mon Mar 02, 2020 10:35 am yes they have a thermostatic bypass at the trans cooler , it loops the trans fluid back to the trans by passing the cooler , until its up to temp
Really? I replaced the factory cooler on my 2011 with a bigger unit and didn't see a bypass. Where exactly is the bypass located and does anyone know what temp it's set to?
2011 9C3: 11.48 @118.
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