# Gen 2 Transmission Trouble



## Iamantman (Sep 24, 2018)

Sadly Betty needs to go to the dealer. Yesterday on a test drive, it started slipping on me and stuttering when downshifting. I limped it home and forgot about it. Then today I checked the fluid level and it seemed ok but then when I took it for a drive it really started acting up and threw two codes and wouldn't go in gear. I pushed it in neutral into a parking spot and tomorrow I'm calling the dealer to tow it in. Had a *P2723* for a stuck solenoid and then because the engine was reving up and it wasn't going anywhere I also had a *P0700*.

I did have an axle seal replaced under warranty about 10k ago and I'm thinking it's just low on fluid but I really hope it didn't do any more damage. I don't want to deal with a rebuild at 20k. I think that's ridiculous. 

I know gen2 powertrain info is limited online so I'll update everyone here for future reference. Hopefully it's just that solenoid and it will be in and out but I am worried.


----------



## Fireworks234 (Jan 4, 2018)

Yeah, haven't heard many transmission failure problems yet. Please keep us updated and good luck!


----------



## HBCRUZE2017 (Jan 25, 2018)

mine used to have this problem around 40-50k and had a tranny flush done and it definately helped out! lol


----------



## Iamantman (Sep 24, 2018)

I just talked to someone at the dealer and apparently the foreman is talking with GM about getting a whole new unit vs rebuilding. I'll find out for sure in a few hours. I have to say though at 20k miles I'm pretty disappointed. 

Fingers crossed it was just lost in translation and the foreman will clear things up with me.


----------



## Fireworks234 (Jan 4, 2018)

Iamantman said:


> I just talked to someone at the dealer and apparently the foreman is talking with GM about getting a whole new unit vs rebuilding. I'll find out for sure in a few hours. I have to say though at 20k miles I'm pretty disappointed.
> 
> Fingers crossed it was just lost in translation and the foreman will clear things up with me.


My guess is that the axle seal was a byproduct and not the cause of the issue. It just showing up later would make some sense if something was just a bit out of tolerance.

Either way, replace/rebuild is going to be better than broken. We know it's not a common thing to have this type of issue so I wouldn't really be too concerned going forward after the repair.


----------



## Iamantman (Sep 24, 2018)

Welp, I'm dealing with a similar issue that folks dealt with a few months back with the labor strike in Michigan. Now the issue is/was COVID 19. I've been given the run around on when my new transmission is arriving for a couple weeks now. Latest is that it was supposed to be here on Thur but wasn't so now they're "hoping" early next week. Ugh. I understand that this is special circumstances and they're all dealing with limited staff but it's so frustrating not being able to get a straight answer. What that tells me is they aren't even reopened yet because when something ships in this country you have a tracking number. If they don't have that, basically it means everyone is guessing.

I've just been giving them a few days in between calls so I don't sound like a crazy person haha. I'm really grateful I don't really *need *my car right now. I do need it for work but I have other options and my work doesn't need me at the office very much at the moment. But this can't go on forever.


----------



## Ma v e n (Oct 8, 2018)

P2723 is a code indicating the TCM has noted a problem with a clutch apply. Low fluid can cause this, but all other causes requires replacement if parts, I've never seen it be a software or wiring issue


----------



## Iamantman (Sep 24, 2018)

Ma v e n said:


> P2723 is a code indicating the TCM has noted a problem with a clutch apply. Low fluid can cause this, but all other causes requires replacement if parts, I've never seen it be a software or wiring issue


Thanks Maven. Have you seen many transmission issues with the gen 2 cruzes you've worked on? 

This seems like a pretty rare problem so far. I've watched a ton of videos on the gm 6t40 in the 1st gen cruzes but not much info about the (6t35) 2nd gen cruzes yet.


----------



## Iamantman (Sep 24, 2018)

Holy crap my transmission finally came in. Fingers crossed I get it back this week!


----------



## Iamantman (Sep 24, 2018)

Yes, finally got my car back! After picking it up I took it for a quick test drive through stop and go, cruising, and highway speeds and it felt and sounded great. No problems up or downshifting, shifted smooth, etc. Fingers crossed that's the last I hear of that until it's a retired old lady on it's last legs haha. 

I didn't get a chance to talk to the transmission tech that worked on it but the service writer told me that when getting approval from GM they dug into enough to find a failed clutch plate that had completely blown up. Metal throughout, stuck solenoids, dead transmission. I'm waiting to get official paperwork tomorrow because of some software issues they were having but they told me I got a transmission re-flash as well so I'm curious to see what that means exactly.

I'm so grateful to have my car back though. Crazy timing with COVID happening right when my car went into the shop.


----------



## Iamantman (Sep 24, 2018)

I could be crazy but I really think with that TCM reflash there was an adjustment to the auto shut off mode on the car. I wonder if there is a TSB on that or something. Seems to be doing that a lot less frequently since having it back. In fact I can't remember a single time it's shut off and thinking back it definitely would have in my daily commute.


----------



## nathanroe72 (Nov 25, 2016)

I'm not aware of any updated calibrations that affect Start-Stop. There is one update (#24280928) for my specific VIN and who knows what exactly GM changed. Usually, the descriptions go in to a little bit detail what each calibration addresses. The only update I've performed on my car was with the HVAC system. 










Now the ECU got some updates but those are more or less for DTC diagnostic enhancements and to correct an issue with the fuel gauge reporting the incorrect fuel level. Your car is a 2017 so there might be different calibrations between the model years though I seriously doubt it. I can't really speak to that, but if you're curious, send me your VIN and I can look it up.


----------



## WillL84 (Aug 5, 2019)

Iamantman said:


> I could be crazy but I really think with that TCM reflash there was an adjustment to the auto shut off mode on the car. I wonder if there is a TSB on that or something. Seems to be doing that a lot less frequently since having it back. In fact I can't remember a single time it's shut off and thinking back it definitely would have in my daily commute.


I've noticed my '17 as/s not working after not driving it for a few days. It didn't work for an entire day then started working normally again the next day.


----------



## Iamantman (Sep 24, 2018)

WillL84 said:


> I've noticed my '17 as/s not working after not driving it for a few days. It didn't work for an entire day then started working normally again the next day.


Oh that's true. I didn't think about the computer needed to remap itself. That makes sense. I'll keep an eye on it and see if things change a bit. So far no problems though which is great but I did notice it wasn't shutting off is all.


----------



## Iamantman (Sep 24, 2018)

Still no auto start stop, but I do know now after researching that if the battery was recently disconnected or discharged it won't activate by design. Just wondering if anyone knows the full parameters here? How long after the battery is reconnected should it start working again? Or what voltage is the cut off for when the system deactivates.

The other thing i thought of on my way home today was that after checking the part number for the new transmission, looks like it's a 2019 unit so I was wondering if because the 2019 models could turn that feature on and off, perhaps I could enable/disable it manually and they just turned it off as part of the install? I dunno, that's probably not it but wishful thinking


----------



## nathanroe72 (Nov 25, 2016)

I've had my battery disconnected a few times and never had an issue with auto-stop afterward. 

This is from GM TechLink:


> *Enabling Criteria*
> The following vehicle conditions must be met for an Auto Stop event to take place.
> 
> Initial minimum vehicle speed during the drive cycle must reach 12 MPH (19 km/h). Subsequent minimum speed may vary from 1-6 MPH (2-10 km/h), depending on the vehicle.
> ...


The full article can be found here: GM Auto Engine Stop/Start Systems – TechLink


----------



## Iamantman (Sep 24, 2018)

Thanks for that info. I'm going to check my battery. The more I'm reading the more likely that's looking. Might have just been a coincidence it corresponded with my transmission repair timing. It's going on two years now so it could just be discharged to the point where it won't engage. I'll check what the voltage shows in the next couple weeks when I change my oil. 

Also the HVAC info is interesting because before I had my car repaired the auto start stop absolutely engaged when the AC was on. But now that's saying that it should not have done that? Unless I'm reading that wrong. Before under normal and under Eco mode, the car would shut off at lights/stops/etc.


----------



## WillL84 (Aug 5, 2019)

Mine will do it with the AC on but it depends on the set temp vs that actual temp. If they're too far apart (hot car and AC hasn't cooled it down yet) it won't engage. I've had mine engage then the car heats up from sitting in the sun and it'll kick off sooner than normal. I think it also won't kick in if you have the defrost on.

But I've had random times where the HVAC was off entirely, warm day, windows down, trans and engine fully warmed and it won't kick in. Sometimes it's only for a stop light or two other times it's the entire drive. My car seems to work say 90% of the time but the other 10% the as/s just won't kick in no matter what.


----------



## Ma v e n (Oct 8, 2018)

Auto stop will engage regardless of whether you are using eco mode or max AC, just depends on parameters 

The trans part number should have nothing to do with your autostop.

A battery on the way out that won't maintain a proper state of charge absolutely will


----------



## Iamantman (Sep 24, 2018)

Thanks Maven. I'll take a look as soon as I can. I got the car the middle of 2018 so it feels a bit early to replace completely but if it doesn't engage below a certain charge that would make sense.


----------



## Iamantman (Sep 24, 2018)

Ooh it shut off today at a stop! I feel like the exact opposite of this forum where everyone complains about auto stop and I just wanna know why mine won't do it anymore haha. It had been a couple weeks and probably a little over 300 miles so it sure took it's sweet time but I guess the conditions were right.


----------



## Fireworks234 (Jan 4, 2018)

After you mentioned this, I realized mine hadn't been doing it as well. I switched my DIC over to the voltage section and noticed my battery wasn't sitting up near 14 like usual, it's sitting as low as it can around 12.3 and not charging up higher. Maybe it has to do with the heat but found it odd. Either way, glad to hear yours is up and running again!


----------



## WillL84 (Aug 5, 2019)

Fireworks234 said:


> After you mentioned this, I realized mine hadn't been doing it as well. I switched my DIC over to the voltage section and noticed my battery wasn't sitting up near 14 like usual, it's sitting as low as it can around 12.3 and not charging up higher. Maybe it has to do with the heat but found it odd. Either way, glad to hear yours is up and running again!


I'll check mine next time it doesn't want to kick in. Interesting.


----------



## Iamantman (Sep 24, 2018)

So I'm curious about something and hoping you guys can help out. I've noticed something on my car and I'm not sure if this is just me being paranoid now that I've had the tranny replaced, or if this was there all along. Everything shifts great up and down, in manual and automatic, and I don't have any weird sounds or vibrations. However, I've noticed that when conditions are right say downshifting for a turn, and then I hit the accelerator exiting the corner the car feels like it "slaps" into gear. Like I can hear and feel a delay between parts engaging and then I'm on my way. It doesn't shift weird at all, just feels like there is "play" somewhere. Could this be something other than the transmission? Axles, suspension, etc?

Does that happen with everyone else here? Please tell me I'm not crazy haha.


----------



## nathanroe72 (Nov 25, 2016)

Iamantman said:


> So I'm curious about something and hoping you guys can help out. I've noticed something on my car and I'm not sure if this is just me being paranoid now that I've had the tranny replaced, or if this was there all along. Everything shifts great up and down, in manual and automatic, and I don't have any weird sounds or vibrations. However, I've noticed that when conditions are right say downshifting for a turn, and then I hit the accelerator exiting the corner the car feels like it "slaps" into gear. Like I can hear and feel a delay between parts engaging and then I'm on my way. It doesn't shift weird at all, just feels like there is "play" somewhere. Could this be something other than the transmission? Axles, suspension, etc?
> 
> Does that happen with everyone else here? Please tell me I'm not crazy haha.


When you say it 'slaps', does it feel like it's in neutral, then when you get onto the throttle it shifts into gear? If that is the case, it's 'normal', at least for my car. Since I've been playing with the trans tuning, I haven't noticed it. Could be that I've been more focused on the shift points and the shift quality. 

If not, it could possibly be a trans mount. Whether it be loose, worn out or simply not 'positioned' quite right. My old Cobalt that I had, the trans mounts were a bit finicky to 'adjust'. They don't have an adjustment per say, but have to loosen the mounts and then rock the engine and trans, then tighten the mounts back down. Not saying that this is a definite thing occurring with your car. Just something to consider. Who knows, maybe these cars don't suffer the same issue.


----------



## Iamantman (Sep 24, 2018)

nathanroe72 said:


> When you say it 'slaps', does it feel like it's in neutral, then when you get onto the throttle it shifts into gear? If that is the case, it's 'normal', at least for my car. Since I've been playing with the trans tuning, I haven't noticed it. Could be that I've been more focused on the shift points and the shift quality.
> 
> If not, it could possibly be a trans mount. Whether it be loose, worn out or simply not 'positioned' quite right. My old Cobalt that I had, the trans mounts were a bit finicky to 'adjust'. They don't have an adjustment per say, but have to loosen the mounts and then rock the engine and trans, then tighten the mounts back down. Not saying that this is a definite thing occurring with your car. Just something to consider. Who knows, maybe these cars don't suffer the same issue.


Yeah I'd be more inclined to think a loose mount would do what I'm describing since it's happening during a shift in weight or load. It's not like neutral dropping it or anything like that. Thanks, I'll take a peak under the hood and see if I notice anything obvious and report back.


----------



## Iamantman (Sep 24, 2018)

Just took a look and on the right hand side there is definitely a bolt that has "shifted" from it's original spot. I wonder if this has anything to do with it.


----------



## nathanroe72 (Nov 25, 2016)

Iamantman said:


> Just took a look and on the right hand side there is definitely a bolt that has "shifted" from it's original spot. I wonder if this has anything to do with it.
> 
> View attachment 288070


That could very well be the culprit. Those bolts are most likely torque to yield (one-time use bolt). If it was me, I'd take my chance twisting that mount and reusing that bolt. There is also a wishbone style mount that bolts to the back of the trans and to the subframe. Wonder if there is a proper procedure for getting the mounts dialed-in. Maybe @Ma v e n can chime in and share their wealth of knowledge.


----------



## Iamantman (Sep 24, 2018)

Yeah not sure if there is any "engine alignment" required. I'd think the mounts themselves (or the body)would have locating pins to keep things square but I'm honestly not sure.

But I poked around some more today and I think I might have a bad inner cv joint. Just tested in a parking lot earlier going in reverse and definitely have a clunk that comes and goes with my acceleration in reverse. I had heard that some before too and I think it might have just been bad timing with the transmission repair. Also noticed some noise over the weekened while we were away when turning and coming to a stop. Seems like an axle for sure but I'm going to take it in to the dealer and ask. Ugh.


----------



## Iamantman (Sep 24, 2018)

Confirmed w the dealer that it's a bad axle. Sheesh I can't catch a break with this driveline! It's driveable but a new part is ordered and will hopefully clear this up and make it feel like new again. I'm def concerned with how many issues I'm having at this mileage but hey, it's under warranty


----------



## Iamantman (Sep 24, 2018)

Ok got the car back and same issue was there. Quote says they verified the concern, confirmed excessive play in the axle, replaced the axle, test drove and did not hear or feel anything anymore. I get in the car and I get to the light right when I pull out and I hear and feel it when I'm leaving. I swear I feel like I'm taking crazy pills every single time I go to the dealership.

I'm going to try to take care of this on my own if I can because I think it's just a loose trans mount causing my clunking/clanking. I posted about this before so I took another look at it looks like another bolt has shifted now (top left) and the third bolt (top right) is loose as well. I was able to move the washer under the bolt head a little with my hands when I reached down there. I just verified this when I got home from work. Take a look at this picture I made of them cropped together.









So my question is do I need to do anything special to "align" this when I go to retighten it or can I just put a socket on it and torque it down? It looks like an 18mm and sadly I only have up to a 17mm socket with me so I need to run to the store to grab a socket. Should I put my jack w some wood under the transmission to take some of the weight off when I tighten it down?

Any help is appreciated! I really don't want to deal with the dealership again until I absolutely have to ugh.


----------



## Ma v e n (Oct 8, 2018)

Those bolts are one time use bolts. They need to be replaced. They get torqued to 74lbft + 60degrees


----------



## Iamantman (Sep 24, 2018)

Ma v e n said:


> Those bolts are one time use bolts. They need to be replaced. They get torqued to 74lbft + 60degrees


Thanks! Anything out of the ordinary when installing them I should be aware of or does the standard take the weight off, hand thread in, release the weight, torque down apply here as well?


----------



## Ma v e n (Oct 8, 2018)

That'll do it!


----------



## Iamantman (Sep 24, 2018)

Got some new bolts on my lunch break and some Taco Bell and fixed it in under an hour for $15 bucks  
All three bolts were very loose and came right out with my 3/8" ratchet. Torqued em' down and rides like butter again. Thanks again @Mavin


----------

