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TECHM (TCM) Laminate Disc Repair

6K views 16 replies 3 participants last post by  alacran 
#1 ·
Guys,

I've been chasing some gremlins with my 12' LTZ as it's been having issues with a delayed shift from Reverse to Drive and from Park to Drive as well as sometimes slow/strange shifting on the highway as well as some slight shuttering between 1-2. I finally broke down and bought a scanner (OBDLink MX2 - Amazon.com: OBDLink MX+ OBD2 Bluetooth Scanner for iPhone, Android, and Windows: Automotive) and even with no dash lights and warnings I pulled 2 transmission codes P0989 and P0877 (Transmission Fluid Pressure Sensor/Switch "E" Circuit Low and Transmission Fluid Pressure Sensor/Switch "D" Circuit Low). After a little research I found the likely culprit to be our wonderful laminate discs on the pressure sensors of the TCM in the transmission as it seems to be a common failure point on the 6T75 transmission that we have. Here's a link to how to do the repair and I won't reinvent the wheel:


Also below are some pics of my TCM as you can see the laminate discs are clearly broken and here's a link to the kit I bought on Amazon (https://www.amazon.com/gp/product/B08RBH7YDH/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) and if you are doing this repair, make sure to seat the discs properly and also the tool for the seal installation is a little finnicky and you need to make sure the seal is pushed in properly to the tool so it will push into the TCM straight. Once the rubber seal is in, check it with a small flat head screwdriver to ensure it's seated fully and plenty of light. The transmission is still relearning and I'll see how it responds after this week as we have a long drive a head to West Texas and it will give the transmission plenty of time to relearn.

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#2 ·
My most noticeavle symptom was reverse or Park to Drive. Up to 3 seconds to feel the engagement of Drive.
But once I changed out the discs, it took about 80 miles and a couple of cold engine starts for the trans to learn- and reflect the immediate engagement of D. literallt a fraction of a second.
 
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#9 ·
It's really not that hard and even if you take your time, it takes about 2-3 hours. Make sure to completely remove the airbox assembly (top and bottom) as it makes it much easier to remove the transmission pan/techm cover and get to all of the bolts. Follow these guides for properly torqueing the TCM and the Pan as well as the install of the discs. The file GM6T70-1E-1L has the TECHM and Pan torque specs and pattern. File 6T70-ZIP-IN has the guide for the Laminate Disc removal and install (pg 6-8). Make sure to keep your bolts in order (use a cardboard punch plate/diagram) as they are different lengths.
 

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#10 · (Edited)
I already ordered the Sonnax tool. I noticed no one is replacing the solenoid filter plate but I would really like one to have on hand. Any help here would be appreciated. It’s the 2009 Traverse LTZ FWD.

Part number 24242274 but I cannot find data that it fits all V6 Gen 1 primarily because it comes in seal kits and TECHM.
 
#11 ·
It's upto you, but I've done this job twice now and never replaced the filter plate and you don't take the TECHM apart to replace the seals so there is no need to replace it if you are doing the seals. Personally, I wouldn't risk it as the plastic gets brittle with old age and you run the risk of breaking something to not having it go back together properly. I was very concerned and biting my lip just removing the TECHM sensor connections when removing it as you know how those tabs can snap easily.
 
#13 ·
Note the extra info i put on sheet.
In red i think is the sequence order to tighten.
The lenght of bolt in mm, and socket size needed
106 in/lb is torque setting.
note its INCH/ lb.....

i bought a small torque wrench in inches.

That long thread on the acadia forum has lots of pics and tips from many users who have done this job.
 
#17 ·
First job is done, I have another 6T70 to do, it was bad three of four disc were broken one so bad the white pressure plate was turned sideways. I missed the Kodak moment. (IMG_7046)

I ordered filter plate part number, 24272468, and it fits. No broken plastic, I worked my from one side to the other. Be aware the filter plate is stuck on there so the noise upon seperation is not pleasant. (IMG_7052)

Thanks everyone for the help.
 

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