GM Transmissions

[dna9656]

The 700R4 was crap, the 4L60E was crap, the 6l80E and 8L90E is crap. GM is just building crap and getting away with it. The Torque Converters (TC) in the 6 and 8 speed transmissions are made of low grade steel and are friction welded, the blocks that are welded on the back of the TC (they provide anchor points for the bolting the TC to the the fly wheel) are harder that the steel around them. They fail, the inside of the TC has problems, the fix for the TC is one made of billet steel. Do a search of " problems with the 6L80 E" and you'll get the whole story, there are problems inside too. GM has a computer INSIDE the trannys, if they need reprogrammed you're off to the dealer or some one who has paid the royalties to GM, about $300.00 per I'm told. In my area, (The US PNW) I'm told it's $8,500.00 to get it it rebuilt with PROPER parts with R & R and only ONE shop is doing it. I found 2 sources on line that claim to fix all the problems, one wants $8,500 for a tranny you have to install and tow to the dealer for programming, the other has a sale now, $2,750.00 or so for a corrected remanufactured unit, 5 year unlimited warranty on parts AND labor. Quit a price disparity. Both website describe the problems and their fixes. I'm ashamed of GM for turning out this kind of crap. The TH 350 and 400 were excellent trannies, even the Powerglide was a great tranny. I think the federal gov't ought to hold GM's feet to the fire and make them produce quality components and provide them free of charge to anyone with a GM product equipped with this junk. I'm in the Chevy legends club, I'm tossing all the stuff they sent me, I'm taking the medallion off my trucks, I have purchased few new trucks (a 87 Suburban) but I have owned over 23 chevy products, (1 Celebrity bought new); I'm not buying GM anything any more. I don't buy Fords either so I'm left with Dodge, you know; it can "Dodge" anything but gas station and a garage". Totally disgusted, ashamed of GM. I should not have to pay for corrected engineering, the people that designed and obviously did not test these trannys ought to be the ones paying.

[asilverblazer]

19 minutes ago, dna9656 said:

the 4L60E was crap

false

[newdude]

1 hour ago, dna9656 said:

The 700R4 was crap, the 4L60E was crap, the 6l80E and 8L90E is crap. GM is just building crap and getting away with it. The Torque Converters (TC) in the 6 and 8 speed transmissions are made of low grade steel and are friction welded, the blocks that are welded on the back of the TC (they provide anchor points for the bolting the TC to the the fly wheel) are harder that the steel around them. They fail, the inside of the TC has problems, the fix for the TC is one made of billet steel. Do a search of " problems with the 6L80 E" and you'll get the whole story, there are problems inside too. GM has a computer INSIDE the trannys, if they need reprogrammed you're off to the dealer or some one who has paid the royalties to GM, about $300.00 per I'm told. In my area, (The US PNW) I'm told it's $8,500.00 to get it it rebuilt with PROPER parts with R & R and only ONE shop is doing it. I found 2 sources on line that claim to fix all the problems, one wants $8,500 for a tranny you have to install and tow to the dealer for programming, the other has a sale now, $2,750.00 or so for a corrected remanufactured unit, 5 year unlimited warranty on parts AND labor. Quit a price disparity. Both website describe the problems and their fixes. I'm ashamed of GM for turning out this kind of crap. The TH 350 and 400 were excellent trannies, even the Powerglide was a great tranny. I think the federal gov't ought to hold GM's feet to the fire and make them produce quality components and provide them free of charge to anyone with a GM product equipped with this junk. I'm in the Chevy legends club, I'm tossing all the stuff they sent me, I'm taking the medallion off my trucks, I have purchased few new trucks (a 87 Suburban) but I have owned over 23 chevy products, (1 Celebrity bought new); I'm not buying GM anything any more. I don't buy Fords either so I'm left with Dodge, you know; it can "Dodge" anything but gas station and a garage". Totally disgusted, ashamed of GM. I should not have to pay for corrected engineering, the people that designed and obviously did not test these trannys ought to be the ones paying.

 

 

6L80 and 6L90 were great when they came out.  07-13, it was 14-20 where the post bankruptcy cuts showed up.  Cost cutting is what messed them up.

 

8L90 currently is great.  95% of the problems stemmed from fluid formulation issues.  

 

4L60 the industry well knows what flaws they have and how to upgrade them. 

 

Ram?  The brand known for the worst transmissions for about 30 years running?  

Edited March 20, 2024 by newdude

[dna9656]

On 3/20/2024 at 8:23 AM, asilverblazer said:

false

I had one, still have one in my S10 2004. The one in my 06 Avalanche crapped out at 130k miles with the standard problems that 4L60E s have. My guy upgraded it with non GM parts, that were made correctly, and there have been no problems. A LOT of the 700R4s had the same problems. I had a '92 4dr Blazer I had to have rebuilt..  a short bed S1 pickup( 1st gen) with a 700R4, had the same problems that '92 had So that's 3 transmissions all based on the 700R4 and the 6L80E, so out of the last 5 Chevys I have owned, 4 of them had tranny problems.

 

Edited March 21, 2024 by dna9656

[dna9656]

3 hours ago, newdude said:

 

 

6L80 and 6L90 were great when they came out.  07-13, it was 14-20 where the post bankruptcy cuts showed up.  Cost cutting is what messed them up.

 

8L90 currently is great.  95% of the problems stemmed from fluid formulation issues.  

 

4L60 the industry well knows what flaws they have and how to upgrade them. 

 

Ram?  The brand known for the worst transmissions for about 30 years running?  

Chrysler used to build a great line of trannies, the 727 and the 927, they had electric shift in the dash, the law made them obsolete. No, HECK no on any Chrysler product, I had an 07 Sebring, with a mitsu engine, that thing is another nightmare.

[KARNUT]

02 Avalanche all original at 184K. One transmission service at 160ishK. 

[PFTX_5.3]

1 hour ago, KARNUT said:

02 Avalanche all original at 184K. One transmission service at 160ishK. 

Yep, had great luck with all of our GM transmissions, drain and filter at 45k

[dna9656]

So, this is digressing into a conversation on the quality of GM trannys. That's not what I'm here for, can anyone tell me why my truck intermittently feels like a hammer is being struck on the frame while going up even slight/medium hills or under load on the flat roads? I think it's the Torque converter clutch disengaging and re-engaging.

[asilverblazer]

2 minutes ago, dna9656 said:

So, this is digressing into a conversation on the quality of GM trannys. That's not what I'm here for, can anyone tell me why my truck intermittently feels like a hammer is being struck on the frame while going up even slight/medium hills or under load on the flat roads? I think it's the Torque converter clutch disengaging and re-engaging.

I think you already know your answer - torque converter. I'm suspect of your transmission guy though. A rebuild should not require a TCM reprogram. Tear it down, clean it, replace damaged hard parts, upgrade the torque converter and put it back in. 

 

I bet you could even replace the transmission and swap your  current TCM to the new transmission with no programming needed.

[ksiesel]

TCM's contain learned values for shift quality.  It's possible the term reprogram is getting used out of context here.  It may simply imply that the rebuilder is resetting the values in the adaptive learning tables so it will more quickly be able to adapt to the new hardware.

[dna9656]

My guy explained to me that the tranny's computer is INSIDE the tranny, GM won't give anyone the goods to reprogram the widget that's inside the the tranny, he says you got to find some one that's paid the royalties to GM or a dealer. My guy is an honest man, straight forward, if you guys talked to him you could tell he's an honest guy. You might call him a man's man. A good guy. After further looking around the Internet I think my guy's info is limited. I have seen quotes under $3k to buy, ship (but I think the install fee might not be included) and install a tranny. Seems there are many placed at the $3k mark. I wonder if the trannys are rebuilt/remanufactured with GM stock parts or the improved billet steel torque converters, improved weldments etc.

 

Edited March 21, 2024 by dna9656

[newdude]

3 hours ago, asilverblazer said:

I think you already know your answer - torque converter. I'm suspect of your transmission guy though. A rebuild should not require a TCM reprogram. Tear it down, clean it, replace damaged hard parts, upgrade the torque converter and put it back in. 

 

I bet you could even replace the transmission and swap your  current TCM to the new transmission with no programming needed.

 

 

Depends.  If contaminates get into the TEHCM solenoids, the it needs a new one.  From OP's many other posts about his transmission, its got 136k on it so a new TEHCM would make much more sense than reusing the old one.  

 

 

41 minutes ago, dna9656 said:

My guy explained to me that the tranny's computer is INSIDE the tranny, GM won't give anyone the goods to reprogram the widget that's inside the the tranny, he says you got to find some one that's paid the royalties to GM or a dealer. My guy is an honest man, straight forward, if you guys talked to him you could tell he's an honest guy. You might call him a man's man. A good guy.

 

 

Correct.  TCM is inside the pan and is a part of the solenoid control pack.  Its technical name is the Transmission Electro-Hydraulic Control Module or TEHCM.  

 

There are multiple reasons the TEHCM needs programming or the shift adapts learned.  Transmission shift adapts need to be learned for the following reasons on the 6L80/6L90:

 

Transmission internal service/overhaul

Valve body repair or replacement

Control solenoid valve assembly replacement

TCM software/calibration update

Any service in response to a shift quality concern

 

If the TEHCM is replaced, not only does it need the shift adapts but before that it needs to be programmed to the vehicle all together as new ones arrive blank aside from any default testing programming.  

 

Sounds to me like your transmission guy is behind the times or is approaching retirement soon and never invested in some simple subscriptions that could make him $$$.  If he does a lot of GM units, then he should have spent the $$ on programming licenses that GM offers access to for independent shops.  Its only $45 per VIN for programming but they can be bought in bulk.  They just need the proper J2534 interface tool such as a GM MDI or MDI 2 or Bosch MDI/MDI 2.  

Edited March 21, 2024 by newdude

[dna9656]

4 hours ago, asilverblazer said:

I think you already know your answer - torque converter. I'm suspect of your transmission guy though. A rebuild should not require a TCM reprogram. Tear it down, clean it, replace damaged hard parts, upgrade the torque converter and put it back in. 

 

I bet you could even replace the transmission and swap your  current TCM to the new transmission with no programming needed.

Too bad you live in OK City; we have plenty of cold beverages in Tacoma. I want a billet TC, I want all the weak spots addressed and corrected. I haven't read anything that says I can have that using GM parts.

[dna9656]

13 hours ago, newdude said:

 

 

Depends.  If contaminates get into the TEHCM solenoids, the it needs a new one.  From OP's many other posts about his transmission, its got 136k on it so a new TEHCM would make much more sense than reusing the old one.  

 

 

 

 

Correct.  TCM is inside the pan and is a part of the solenoid control pack.  Its technical name is the Transmission Electro-Hydraulic Control Module or TEHCM.  

 

There are multiple reasons the TEHCM needs programming or the shift adapts learned.  Transmission shift adapts need to be learned for the following reasons on the 6L80/6L90:

 

Transmission internal service/overhaul

Valve body repair or replacement

Control solenoid valve assembly replacement

TCM software/calibration update

Any service in response to a shift quality concern

 

If the TEHCM is replaced, not only does it need the shift adapts but before that it needs to be programmed to the vehicle all together as new ones arrive blank aside from any default testing programming.  

 

Sounds to me like your transmission guy is behind the times or is approaching retirement soon and never invested in some simple subscriptions that could make him $$$.  If he does a lot of GM units, then he should have spent the $$ on programming licenses that GM offers access to for independent shops.  Its only $45 per VIN for programming but they can be bought in bulk.  They just need the proper J2534 interface tool such as a GM MDI or MDI 2 or Bosch MDI/MDI 2.  

You appear to be a fountain of information; thank you for exposing the secret(s) of OD 2 to the rest of us. Most of US are just people trying to make sense of some part of our world we all live in. Thank you for your revelations on modern OBD 2 operations.

 

[diyer2]

I get your frustrations dna9656, and to a point I agree. I have owned a few GM pickups and replaced the trans in one of them a 4L60E. This truck was used for towing on a regular basis in the mountains of Colorado, it was also my daily driver and I worked in construction. Bed was always full of tools or material. I did regular trans fluid changes and it went over 200k miles before being replaced, everything wears out eventually. 

My 2012 Sierra trans has performed great with regular fluid changes. 

The members on here who know me know I'm big fan of fluid changes, all fluids and it has served me well.