Just had a transmission failure...

[mikeyk101]

No warning, just failed in middle of nowhere. Nothing in "D", "M", or "R". Even tried turning truck off and restarting and had same results. Luckily Onstar worked and maybe an hour and half, truck was on flatbed headed to local dealer. It is a 2016 Silverado with 6L80 and 96000 miles. I was not really surprised after seeing so many threads on this.

 

I fully expect to hear that the transmission has gotten totally trashed. But I am curious. I'm guessing the torque converter most likely grenaded. Now if it did, shavings will have worked through the trans and caused the failure. What prevents shavings from going into the transmission cooling lines and then into the tubes inside the condenser? Is it normal practice for the transmission cooling lines to at least be flushed or replaced in this situation? And if shavings made it into lines, what about condenser? Can that be flushed or does it need to be replaced? I would imagine if shavings can get in there, if those are not replaced, I can expect another failure shortly thereafter?

[mikeyk101]

Well I heard back from dealership and was told that the transmission needs to be replaced. They are supposed to receive the replacement by Saturday and the job should be done by late Mon afternoon. And the good news is that GMPP has approved the job so once again my protection plan came to the rescue. 

 

I had a conversation with service manager about the transmission cooling lines and condenser. He said that the normal procedure is to flush the lines as well as condenser. I'm a bit leery of this and still concerned that shavings could be left behind and another trans failure could happen. A buddy of mine had a 2015 with the 6 speed that suffered a trans failure about 2 years ago. And over the next year, not only did that replaced transmission fail but 3 more after that. 4 transmission failures in a years time is unacceptable. My first thought was that it probably had metal shavings left behind in the lines causing this. He didn't know so I am not sure if this was cause but still worries me. 

 

The good news is I still have one more year and/or 25000 miles left on my GMPP plan so I'm not worried about cost, just don't want to go through the same aggravation.

 

From other threads, like I mentioned before, it seems like the torque converter is the weak spot. I have seen aftermarket torque converters recommended and wonder if it might be to my advantage after getting back home to have one installed as I'm sure I will be ending up with an OEM in the replacement transmission. Any thoughts on this?

[MikeBMW]

Sorry about your experience, man, that sucks!
I really have no experience to relate - I always replace my transmission fluid at every other oil change but, then, I'm only at 92K miles or so.
A friend of mine (who pretty much ignores maintenance) is on his second transmission with his 2014 but, fortunately, he had a warranty on the first one. Not sure if it was a torque converter issue with each one.
Regardless, I drive mine like crazy, pedal commander and all, and it still has no issues so I would think the stock torque converter should be sufficient as I'm sure you have the G80 locker.
 

Edited March 16, 2024 by MikeBMW

[mikeyk101]

13 hours ago, MikeBMW said:

Sorry about your experience, man, that sucks!
I really have no experience to relate - I always replace my transmission fluid at every other oil change but, then, I'm only at 92K miles or so.
A friend of mine (who pretty much ignores maintenance) is on his second transmission with his 2014 but, fortunately, he had a warranty on the first one. Not sure if it was a torque converter issue with each one.
Regardless, I drive mine like crazy, pedal commander and all, and it still has no issues so I would think the stock torque converter should be sufficient as I'm sure you have the G80 locker.
 

 

Yes on the G80 locker. And I don't change the trans fluid as often as you but it was done at 49000 like was called for and I was due to getting it done on this next oil change. Maybe more frequent changes are called for.

 

Interestingly I had found out about a month ago AMT Warranty which was the authorized provider for the GMPP was replaced last year by another company when my starter failed. Not sure who it is. But according to the service writer, AMT has become an absolute bear to deal with. They are not very good with approving claims now. Service writer said that many transmission claims have been denied over last several months. He said they have been sending out adjustors who look to see if oversized tires and/or lift kits are on the truck. Then they take photos of truck, deny the claim, then cancel the protection plan on the spot. Luckily mine was approved. I'm guessing they are just trying anything to get rid of as many of the remaining contracts as they can so they can wash their hands of GM. Unfortunately for them, they are stuck with me for most likely another year. 

[mikeyk101]

My Silverado was finished up late this morning with replacement trans installed and I immediately blasted for home.  I just pulled into driveway a half hour ago and 850 miles later. It seems to be fixed except it is running a bit hot at times. I can tell by the temps that it does have the updated thermo valve as dealership called it otherwise known to us as transmission coolant thermostat. First couple hundred miles, I did check it randomly and it seemed to stay right around the 154⁰ temp. Some time after driving North through Tennessee, I again checked and it was now at 160⁰. This was during normal driving speeds. With my original trans with updated thermostat, it usually bounced between 147-154⁰ while running down the highway. In stop and go traffic, it would rise to upper 160's to mid 170's but would quickly drop back down when getting going again. 

 

This time though while dealing with rush hour Nashville traffic for almost an hour, it would get up to upper 180's but when traffic would open up a bit, drop slightly but then rise again when caught back in stop and go. Once Nashville was in the rear view mirror and back moving at highway speeds again, it took well over 15 minutes before it cooled down to mid 150's. It never took that long to drop down. It never dropped below the mid 150's for pretty much the rest of the trip up until maybe last hour. Finally towards end of journey when outside temps were in upper 30's, the trans temp dropped down to low 150's and held. 

 

I'm wondering if there may be some kind of restriction somewhere in trans cooling lines or the condenser. I was told that part of the repair included flushing the trans cooling lines and that should clear anything that may have gotten in there. Another thing is the service writer really stressed that I should check the trans fluid level after getting home. He said the tech checked it after doing a road test and the level was fine but to be sure, check again once home. I'm too tired to do it tonight but plan on doing it in the morning. Obviously I first have to get trans fluid up to temperature before checking. But could my issue be caused by the fluid being slightly low?

[mikeyk101]

And I guess a faulty trans thermostat is also a possibility like what this member had happen to him

 

https://www.gm-trucks.com/forums/topic/265797-updated-6l80e-thermostat-question/

[mikeyk101]

This is slightly off topic but I will finish back on topic.

 

I discovered after reading my GMPP contract that I can get reimbursed for up to 4 days hotel stay as well as meals which I didn't know. I did at least get the hotel receipts to submit but only have a couple of meals receipts. Oh well, now I know for next time.

 

But, I called up GMPP because I wanted to find out how to submit the receipts for the claim. While I was on the phone, I also asked if there was any kind of warranty on the transmission and if so, what it was. I was told with it being an actual GM rebuilt transmission, I am covered for 3 years on it as well as 100,000 miles! Nice. So this will now extend my coverage on the transmission for at least 2 more years past my GMPP which expires in 1 more year or 25,000 more miles. Looks like I will be holding on to this truck for a few more years now. And I was told most major components such as replacement GM engines also get the 3 year 100,000 mile coverage as well. Not that I want an engine failure but as many know, the lifters on these AFM engines are an Achilles heel. If it's going to happen, I hope it happens soon.