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Posted (edited)

New owner of a 2015 Sierra 5.3 here. Might be beating a dead horse on this one, but is there any preventative maintenance or measures that can be taken to prevent the supposedly inevitable failure of the 6l80?

 

Currently the truck drives very smooth, no indications of a failing torque converter. Previous owner kept all service records, nothing major ever needed on the truck, also never replaced transmission fluid fwiw.

 

Was reading about installing an upgraded torque converter, is this a step others would recommend, considering the truck seems to be doing fine as is currently? Or just keep plugging along and hope for the best?

 

Trying to keep this rig for the long term as it is my dd. 

 

Any input appreciated, thx in advance 

 

Edit: 82k miles

Edited by inspectahdeck
  • Like 1
Posted

Yes, there is. 1. Do the Transmission Thermostat "pill Swap" or add the new device out there from Shift Tech. Several links in this video for the information.

2. I'd change the fluid. You didn't mention how many miles on it.

I did the Pill Flip & transmission runs MUCH cooler. Sort of like the older generation transmission that didn't have this device.

 

 

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Posted (edited)

1.) The converter issue is a design flaw. It's not just a bad batch of them. When it fails the debris takes out the rest of the unit. This is never just a 'replace the converter' issue when they fail. It WILL kill the pump and valve-body as well as trash the clutches and bearings. New pumps are hard to come by. Few shops will re-machine them. Fewer still get it right. 

 

I own a 2015 with this transmission BUT behind a V6 that uses a different captive clutch converter. Failure rates of this transmission behind a V6 are nearly nonexistent. IF my truck had a V8 I would have replaced the converter with a Billet clutch unit like the one below the day it became available. 

 

CADILLAC, CHEVY, GMC Torque Converter 77-JMBXSD (floridatorqueconverters.com)

 

Here's an explanation of the issue from the people that make the parts used to modify them: 

 

6L80, 6L90 Transmissions: Consider an Updated Converter in Your Next Rebuild | Sonnax

 

2.) As @rav3 notes, keeping check on heat is huge in these units. The "brains" are in the fluid. Use the kit. Flip the pill. Use the new GM 70C/158F thermostat but get rid of the 192 F unit that's on it now. Monitor you temps afterwards. If it won't stay under 160F then you need more cooler as well. You can find one with a Google search. Improved Racing, Setrab, MHX, Mocal, Mishimoto, Hayden, B&M and Derale come to mind. 

 

 

3.) Fluid and filter changes. Use the severe schedule. 45K mile fluid swaps minimum. I do 25K. This is a pain the first time as the pan hasn't a drain. There are several manufactures that make pans with drains, or you can have one fitted to the existing pan. I use an 8-quart PML alloy pan. They have a factory sizes 6 quart. B&M has one. There may even be a steel pan by now I don't know about. Look around. AC-Delco filter is fine. They are all dog and cat catchers. About 100 microns. 

 

 PML GM 6L80, 6L80E Deep Transmission Pan (yourcovers.com)

 

4.) Use a better fluid. Red Line, AMSOIL...... Something PAO or PAO/POE not mineral based. 

 

First four are my 'have to do' list. 

 

5.) SONNAX Zip Kit

6.) Blackbear tune

 

There's the 'wish list'. 

 

Edited by Grumpy Bear
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  • txab pinned this topic
Posted

My truck has 58k miles on it and I already have hard shifts pretty frequently with the 6L80. The torque converter swap is not something I'm capable of doing in my apartment parking space, but I do want to attempt some of these other recommendations. Already changed the fluid early this year which didn't seem to have a major effect.

  • Like 2
Posted

Like Grumpy said, it is a design  flaw.  I did everything to prevent it on our 2016 Suburban, early fluid changes even with AMSOIL, deleted the thermostat and deactivated the AFM and  it still happened.  Just prepare for it is all you can do.

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Posted
1 minute ago, inspectahdeck said:

@Black02SilveradoWould replacing the torque converter with an improved billet design prior to failure prevent the transmission from failing in the future (theorhetically)? Or is this transmission that bad where it will ultimately fail no matter what

 

Sorry to but in, but it isn't theory. When the converter clutch fails it is the garbage from that failure that destroys everything else. Like throwing a bucket full of sand in the box. 

 

Now can the transmission fail for another reason. Sure, just like any mechanical device. There are no absolutes. But the billet converter will absolutely prevent this very common total transmission destruction. The one in the link requires zero programing changes. There is no change in stall. It's just been bullet proofed. 

 

 

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Posted
2 hours ago, Western96 said:

My truck has 58k miles on it and I already have hard shifts pretty frequently with the 6L80. The torque converter swap is not something I'm capable of doing in my apartment parking space, but I do want to attempt some of these other recommendations. Already changed the fluid early this year which didn't seem to have a major effect.

What brand did you use? I extracted/refilled 3.5 quarts using Amsoil 1,000 miles ago and even that amount made a difference. My transmission shifts smoother than it did before.

  • Like 3
Posted
3 hours ago, inspectahdeck said:

@Black02SilveradoWould replacing the torque converter with an improved billet design prior to failure prevent the transmission from failing in the future (theorhetically)? Or is this transmission that bad where it will ultimately fail no matter what

Again, like Grumpy stated, other issues can arise but yes, putting in a billet torque converter will prolong the life as long as you disable the AFM as well. 

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  • 3 weeks later...
Posted

I picked up a 2014 Silverado LT 141k miles in October. My first Chevy. I had to leave ford behind. The 5.4 was the final nail in the coffin for me. Anyways. I'm loving the truck so far. I did all my homework before deciding what I wanted to get. I actually didn't want one this new but all the 2004 to 2008 Crew Cab 4x4 trucks are priced ignorant now and for the past 2 years really. I just can't pay $15000 for a old arse Cat eye with 300k on it.  Found this 2014 it checked all the boxes so I popped.  My plans, god willing, is to drive the wheels off this thing. I did my tranny over the thanksgiving break. I installed the Superior Solutions kit in the thermostat. The transmission was stressing me out the first day I got it. Damn thing would run up to 195 just driving down the road. Now the highest I have seen is 160. Stop and go traffic. Interstate runs about 145. Good peace of mind now. The install is super easy. I also did my filter and flushed out all the fluid. Running fresh Amsoil now. Here are some good videos on the process. 

Don Smith  has a lot of knowledge. Only pain part is getting that pan out. Damn engineers. I had to take the tranny lose from the crossmember and jack it up against the body. Still was a pain. I would suggest a buddy. I would not have been able to get the pan out by myself. I still had to pry the exhaust down while he yanked it out. I did not install a drain plug. I would suggest planning that if you are keeping the truck for any length of time. Or replace the pan. Huge cost difference between those options. She purrs now. Smooth shifts. I'm very happy with the outcome. I flushed it until it was clean fresh fluid coming out. Took about 16 quarts I think. I wanted to make sure I got it all out the converter also. That's including the fill. The magnet was clean nothing abnormal on it. I hope I got lucky. I will be doing my Front and rear next. Also hearing something about the drive shafts exploding at high speeds. I'm not drag racing my truck so I am probably safe but still something to keep an eye on. Luckily the previous owner deleted the DOD/AFM. I don't have any history on the truck. I am still learning a lot. I hope it was done the best way by replacing the cams and lifters etc. But I have not dug that deep yet. I could have an upgraded torque converter for all I know. Need to see if there is a way to peak in the bellhousing and check. Those are the 3 biggest bullet proof items I know of. Keep an eye on your sharkfin. They tend to leak if it hasn't been replaced. I did that a few weeks ago. Easy fix. Also have the AC condenser weld leak you may be dealing with. If your AC goes out check the right side of you condenser if it's wet that's the issue. Below are some videos on the AC issues.

 

Sorry it's a little long winded. But we all have to stick together. If you take your truck in for the AC condenser they will try to charge you $2000 when you can do it yourself for maybe $300. 

I am loving the package chevy has put together in this Silverado so far. Hope some of this helped. 

 

Here is my girl. Damn sexy rig I must say. Nice and stock.

image.thumb.png.37c0ef6157443c1574e4771af565144d.png

  • Like 5
Posted (edited)

Also, there is this:

I had it done and a friend of mine just did the same a few weeks ago on his 2016 GMC  - solved all of his transmission stutter issues ... so far.
Mine's doing great after two years.

Edited by MikeBMW
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  • 2 weeks later...
Posted

Manufacturer: Chevrolet

 

VIN Characters: 17 (beginning with MA6...)

 

Decode:

 

7th character represents the MONTH of Manufacture

9th character represents the YEAR of Manufacture

 

Month Codes:

 

A = JAN

B = FEB

C = MAR

D = APR

E = MAY

F = JUN

G = JUL

H = AUG

J = SEP

K = OCT

L = NOV

M = DEC

 

Year Codes:

 

A = 2010

B = 2011

C = 2012

D = 2013

E = 2014

F = 2015

G = 2016

H = 2017

J = 2018

K = 2019

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