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...after she started noticing a delayed shift into Drive (from any other gear, no other symptoms or codes). \
I wanted to verify if your symptoms match mine before I proceed with this type of fix. Occasionally, and while driving at highway speeds (60+), the transmission will fail to shift into either 5th or 6th gear in our 2009 Acadia with 144,000 miles on it. If it is stuck in 5th I will notice the tach up around 2,000rpm or so. Sometimes I can coax it into overdrive by letting off the pedal entirely for several seconds. And then there are times that it will be in 4th and the engine is near 3,000rpm. After awhile, either by the let off gas trick, or just time, it will go back to 6th. I have no codes being thrown.

I also have another transmission problem which I think is a completely separate issue; failure to shift from overdrive to 5th or 4th under light acceleration and heavy load. But that's for another thread...

Thanks, Tom
 
Erratic Downshifting @ Highway Speeds - TCM?

I apparently have the same issues as Gunn with my 2008 Acadia, 137k miles. Sometimes I notice RPM "flair-up" increase when down shifting at highway cruising speeds. I back off accelerator pedal and trans will go back into 6th. If I step on accelerator more aggressively trans will downshift to 4th or 5th. I first noticed this condition last summer. I had the wave plate and fibers replaced last summer before wave plate broke. No internal damage to trans. TCM was inspected when wave plate was replaced and no membranes had failed. But, now same shifting issue is back this summer. No codes have been thrown.

I'm thinking it's most likely the TCM. I want to check to see if others besides Gunn and me have experienced same highway driving shifting issue, and if TCM repair/replace solved it.

Thank you. Mike
 
2008 Acadia w/ 137k. Intermittent problem shifting out of 1st gear. Throws a CEL light too. Pull over shut off the engine. Restart, everything ok but CEL stays on for about a day. Lost the Wave Plate at 40k. GM has extended the power train warranty to 144k due to numerous issues with this vehicle. Took it in today and of course, "could not duplicate". They said transmission fluid service was overdue. Not correct since all was flushed at 40k but I played along. CEL code is 0752. I know I'll be returning.
 
Need to do this DIY. However, the pictures in the OP are no longer there. Is there any way to get these pictures?


Also, anyone in North Carolina do this repair?







.
 
unfortunately its the Photobucket issue.
blocking his pics... hed have to pay $400 to photobucket to be able to display his pics.
 
unfortunately its the Photobucket issue.
blocking his pics... hed have to pay $400 to photobucket to be able to display his pics.
Photobucket got real squirrelly. You can't even view what someone has stored there if you know the user's screen name. It's a shame some folks didn't move their files to a better (and probably free) cloud service before Photobucket shut the door.
 
Does anyone know the torque specs on the bolts or do I just tighten them pretty well? Anyone have a subscription to Alldata pro that could look up these specs for me? Would greatly appreciate it.
 
Does anyone know the torque specs on the bolts or do I just tighten them pretty well? Anyone have a subscription to Alldata pro that could look up these specs for me? Would greatly appreciate it.
There is a Youtube video about replacing this transmissions TEHCM. In the remarks, someone asks about torque specs and tightening sequence. An answer is provided by someone seemingly knowledgeable about the job.

If you know the fastener size and type of thread, the Society of Automotive Engineers (SAE) chart of fastener torque specs is a good place to look. Be sure to use the shaft size and NOT the size of wrench used to tighten the fastener. Manufacturer's engineers use the SAE fastener guide when selecting nuts, bolts, and studs while designing their products.

Use your 'net search skills to find this information.
 
There is a Youtube video about replacing this transmissions TEHCM. In the remarks, someone asks about torque specs and tightening sequence. An answer is provided by someone seemingly knowledgeable about the job.

If you know the fastener size and type of thread, the Society of Automotive Engineers (SAE) chart of fastener torque specs is a good place to look. Be sure to use the shaft size and NOT the size of wrench used to tighten the fastener. Manufacturer's engineers use the SAE fastener guide when selecting nuts, bolts, and studs while designing their products.

Use your 'net search skills to find this information.
Found it. Thank you so much. You are amazing..!!!!!! :thumb:

12Nm torque tightened in sequence starting center bolt moving outward. Lowest center bolt is 55mm long, 4 bolts directly above it are 80mm long. Next bolt above the 55mm long bolt, but offset is 65mm long. Three bolts somewhat aligned above the 65mm long bolt are 95mm long, then somewhat above those comes the 42mm long bolt and somewhat above that one is the 65mm long bolt. Best of luck!
 
Just did this repair working 3 hours/day for 3 days. (The sun got into my eyes too much for me to continue, otherwise I could have done it in 1 sitting in about 6-7 hours)

My thoughts:

1. I used the Sonnax kit. Kit is good and comes with tools to help install and set the seals. However, I had a difficult time setting the seals. I must have done each one 10 times. Just couldn't get them to set. The tools in the kit are flimsy (to be thrown away after job is completed). My tools deformed. I knew that if I couldn't set the last seal on that last attempt, it was going to mean ordering another kit just to get the new tools. Be careful pushing the rubber washers into the tool and don't let it bend while you are pushing it in, otherwise setting tool will deform. Mine did. Very weak metal, and very thin.

2. The skills and know how needed is not more than the ability to do a brake job. However, it is a ***** to get to all the bolts. Very time consuming

3. Get a subscription to alldata. I had a mechanic print me out pics and directions. (I gave him $5, even though he didn't ask me for it) Do NOT do this without alldata info. Very important to get the order right as to which bolts need to come out first and even more important which bolts need to be installed in which order and MOST important is to torque them correctly and in order.

4. Most of the time is spent taking off the pan and TEHCM. Lots of bolts. Installation is a lot faster because you now know where the bolts go. Lots of different length bolts. Very important you make a note of them. I kept each different size bolts in different plastic baggies and wrote pertinent info about the bolts on a sheet of paper and put it in each of the plastic baggie. (Size, quantity of each size bolt, and location). Also, I color coded the different bolts by using different color highlighters on the printed out diagrams. This was immensely useful when the time came to reinstall the bolts.

5. If you have long slender arms, you'll be fine. Small hands are also a plus. (I have short arms so it was difficult for me to reach. Had to do a lot of acrobats and did a lot cursing)

6. Again TORQUE is important..!! No need to buy a torque wrench, Autozone has a tool loan program and it's free. Go borrow one from them. DO NOT start this job without a torque wrench.

7. 3 days worth of tranny fluid drain, (dripping, dripping, dripping). I used 5 quarts total. I put in 4 quarts initially, put the car in all gears. Then took it for a 3 mile drive, stop and go. Came home and rechecked, was 1 quart low so I added another.

8. No leaks.

9. I replaced both gaskets. One for the pan cover and one orange one for the electric connector. Ordered from Walmart. Got both for less than $15 delivered to home. Genuine AC Delco. DON'T SKIMP ON THIS. At first I was not going to bother, but then I thought that since I'm already dissembling everything, might as well. I am SO GLAD I did. The old orange gasket (electrical connection) was visibly deformed due to age, compressed. Newer one was plumper. The pan gasket was hard and brittle, even though it was still working. Glad I did these. Peace of mind. You don't want leaks later on. Otherwise you have to remove the pan again. It's not fun.

10. I removed the TCM fuse to reset it before starting the car first time. You only need to remove it for a few seconds.

11. ******** I read that someone here had hard shifts for the first few days until the computer relearned and then his shifting got better over time.****** I did not experience this at all. My shifts were as smooth as butter. *******

12. Definitely lots of cursing. Lost my patience several times when I couldn't get to a bolt or when I was trying to slide the cover back on. TAKE A BREAK. RELAX AND THEN COME BACK AND TRY AGAIN. You don't want to be impatient and force things because they will break. Do it slowly and follow the direction to the tee on alldata.

Best of luck.
 
Hello. I have a 2008 Acadia with ~135K miles that threw a Check Engine Light and codes P0752 (Shift Solenoid A Stuck On), and P0700 (Transmission Control System Malfunction) yesterday 4/8/18. I've opted to replace the laminate discs and seals under the old rule "try the cheap fix first".

TEHCM bolt lengths by location and torque order can be found on the Sonnax web site under their Zip Kit 6T70-ZIP instructions:
https://www.sonnax.com/parts/3757-zip-kit

Thanks,

Tim
 
All bolts are torqued to 106 in-lb in the following order:

TOP
__________
--[11] <-64mm
----[9] <-42mm
----------[7] <-80mm
---[5] <-95mm
----------[3] <-80mm
-----[1] <-95mm
-[2] <-95mm
----------[4] <-80mm
----------[6] <-80mm
---[8] <-64mm
----------[10] <55mm
__________
BOTTOM
 
Hello. I have a 2008 Acadia with ~135K miles that threw a Check Engine Light and codes P0752 (Shift Solenoid A Stuck On), and P0700 (Transmission Control System Malfunction) yesterday 4/8/18. I've opted to replace the laminate discs and seals under the old rule "try the cheap fix first".
Just wondering if you've done the repair yet? I'm getting the same codes and leaning towards the disc kit too. I have slightly less miles and the wave plate was done a few years ago.

Does anyone know if there are other wear items in the TEHCM that commonly fail? If so, it may be worth getting the whole unit for $400ish. For example, we have the codes but also some slow shifts and clunks when shifting into R or D. No shuddering. Fluid is clean.
 
There was a thread on one of the 3 forums- with pics and all- great post.
I wonder if the photobucket issue affected it.....
I guess it was this thread.... going back to post 1. no pics.
 
Does anyone know if there are other wear items in the TEHCM that commonly fail? If so, it may be worth getting the whole unit for $400ish. For example, we have the codes but also some slow shifts and clunks when shifting into R or D. No shuddering. Fluid is clean.
You have the option of rebuilding the valve body once you get to the point where you change the solenoid diaphragms. Kits are also available for this rebuild.
 
There was a thread on one of the 3 forums- with pics and all- great post.
I wonder if the photobucket issue affected it.....
I guess it was this thread.... going back to post 1. no pics.
Yeah, it was this thread. I went thru this so I have saved the pics. I am attaching the pics from the OP (stpete). There is also some pics on post #41 not impacted by the photobucket mess. I think I may have other pictures from this thread saved that I should be able to upload later today.

Enjoy!!
 

Attachments

Yeah, it was this thread. I went thru this so I have saved the pics. I am attaching the pics from the OP (stpete). There is also some pics on post #41 not impacted by the photobucket mess. I think I may have other pictures from this thread saved that I should be able to upload later today.

Enjoy!!
These are great. Thanks to all who have helped with additional info and pics.
I have ordered the sonnax kit and both gaskets. I still have a few extra tools to pick up, any other photos of the tcm and cover removal?
 
Yep! I did the repair yesterday. 3 of the 4 laminate disks had a circle worn in the middle from the piston. Everything is shifting fine so far.

~Tim
 
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