Chevy 1500 Transmissions

[SlugSlinger]

His tear down videos are informative. He explains weaknesses and how to make improvements.

 

[Roy14]

The 4L60e 6 speed seemed more reliable than the 4L80 when I worked at the GM dealership. Not to say I never saw one fail.

You are the first person I’ve ever heard that from. Pretty sure all “4Lxx” transmissions are 4 speeds as well.

 

[okierider]

I bought this truck for my oldest son in 2012 IIRC with 5300 miles on it, and he drove it until 2020. It had 51k on it when I got it back, and as I said, it now has basically 80k. It’s got the 4.3l v6 motor and is the most fuel efficient truck I own. It’s the “work truck” package with roll up windows, manual locks, and rubber floor mats, and I’ve intended to keep to literally use as a street legal UTV since I couldn’t buy a new Polaris or Canam side by side for what it’s worth.
Thanks for the input, and I’m sure y’all are right that I just need to keep driving it and quit looking for problems where there are none.

You always get those "helpful" people who think they know what they are talking about cause cousin Eddy was splaining about transmissions whilst cleaning his white loafers... Amazing how a couple issues happening turn into those vehicles have this or that issue. Ifr you drive it like you care and keep those fluids right it will be fine ...maybe Got a buddy with a green-ish chevy and the same setup.........closer to 200,000 than 80,000 ....... great truck. We just changed a couple brake pads and the rear shocks and decided it is time for him to get the broken exhaust mount replaced LOL. do not think it is 2011 but close to the same. And he gets way better fuel mileage than my Tundra LOL.

 

[retrieverman]

For reference, this is the truck I‘m talking about.

 

[gl55]

Here is the deal with the 6L80/90 transmissions. Up until 2014, the TCM commands torque converter clutch lockup starting in 2nd gear and up. Starting in 2014 it commands TCC lock up starting in 1st gear and up. But it is not a positive apply to the TCC clutch. It slips the lock up clutch 20 rpm when locked up and if equipped with DOD/AFM it slips it 40 rpm in that mode when driving. This causes over time the clutch lining to progressively wear away. Eventually the clutch material circulating in the fluid will eventually plug up the filter and end up starving the pump for fluid causing low fluid pressure and thus burning up the clutch packs and causes transmission failure. It seems to happen between 100K to 160K miles according to several transmission shops I deal with that rebuilds them. They all say the TCC clutch failure is the cause of 95% of the failures on those transmissions. What you can do to prolong the life of the transmissions with custom ECM/TCM programming is to set the calibration to keep the converter unlocked until only 5th and 6th gear from 50 mph and higher and 0 RPM slip. That also makes them drive better and feel more responsive. Another thing you can do if you don't have access to ECM/TCM programming is when they get to 75K-80K miles, drop the pan and change the fluid and filter and put in a new GM torque converter. Doing that wil remove almost all of the contaminated fluid in the transmission as just draining the pan only removes about 1/3 of the fluid as about 2/3 if the total fluid stays in the torque converter and you will start out again with a new TCC clutch. That will be cheaper than a complete rebuild.

 

[JH47]

I’ve heard this from several people, and have read on forums of some guys upgrading their TC before it causes an entire rebuild.

It's not the converters that are flawed. It is the stock tuning constantly slips the converter when locked. Get a tune that eliminates the slip and they will last much longer.

 

[retrieverman]

Here is the deal with the 6L80/90 transmissions. Up until 2014, the TCM commands torque converter clutch lockup starting in 2nd gear and up. Starting in 2014 it commands TCC lock up starting in 1st gear and up. But it is not a positive apply to the TCC clutch. It slips the lock up clutch 20 rpm when locked up and if equipped with DOD/AFM it slips it 40 rpm in that mode when driving. This causes over time the clutch lining to progressively wear away. Eventually the clutch material circulating in the fluid will eventually plug up the filter and end up starving the pump for fluid causing low fluid pressure and thus burning up the clutch packs and causes transmission failure. It seems to happen between 100K to 160K miles according to several transmission shops I deal with that rebuilds them. They all say the TCC clutch failure is the cause of 95% of the failures on those transmissions. What you can do to prolong the life of the transmissions with custom ECM/TCM programming is to set the calibration to keep the converter unlocked until only 5th and 6th gear from 50 mph and higher and 0 RPM slip. That also makes them drive better and feel more responsive. Another thing you can do if you don't have access to ECM/TCM programming is when they get to 75K-80K miles, drop the pan and change the fluid and filter and put in a new GM torque converter. Doing that wil remove almost all of the contaminated fluid in the transmission as just draining the pan only removes about 1/3 of the fluid as about 2/3 if the total fluid stays in the torque converter and you will start out again with a new TCC clutch. That will be cheaper than a complete rebuild.

I’ll be honest. I don’t understand much of what you just said, but I’ll look into a new torque converter.

 

[gl55]

It's not the converters that are flawed. It is the stock tuning constantly slips the converter when locked. Get a tune that eliminates the slip and they will last much longer.

Even when you zero the slip tables they still slip 4-5 rpm when monitored with a scan too. You need to eliminate lockup in the lower gears to prolong their life.

 

[swampratt]

Wonder if changing the fluid and filter every 20,000 miles like the old days would prolong the life of these OD transmissions.

I have 3 2004R transmissions and many valve body and parts for them but can't bring myself to give up on my very reliable TH 350 transmissions.
One day I may stick one of those into something I own.

 

[gl55]

Wonder if changing the fluid and filter every 20,000 miles like the old days would prolong the life of these OD transmissions.

I have 3 2004R transmissions and many valve body and parts for them but can't bring myself to give up on my very reliable TH 350 transmissions.
One day I may stick one of those into something I own.

You would still have the issue of the TCC lining material wearing away and eventually becoming metal on metal. It's the continuous slipping TCC engagement starting in first or second gear that just wears it away.