6 Speed trans whine and replacement MASTER thread
- Thread starter boydnhere
- Start date
CharlieSierra
New member
Thank you for the advice, but I will probably not buy a transmission from a salvage-yard.
This lengthy thread, "6 Speed trans whine and replacement" is a testament to the fact that this transmission has issues. Two Chevy dealerships failed to recognize the issue with my car when when I brought it to them within the warranty period, and now Chevy Customer Assistance declines to cover the cost of repair. One would expect GM to stand by their products in order to maintain brand integrity and build customer loyalty.
Tesseract_Indeed
New member
My 1.4t auto also has a lot of rev hang. I am deeply considering doing a M/T swap for the hell of it this summer. Depends on what would cost more: doing a M/T swap, or selling my auto and buying a manual. I have only done a few mods, mostly DIY stuff, so I wouldn't gain or lose any more money from keeping my modded sonic.
Yeah I understand your concern. Unfortunately not much can be really done. Not sure how much a transmission goes for new.
Papasonic
Active member
GM Parts Direct lists the manual 6 speed for $1699.83
2012 Chevrolet Sonic
Change vehicle
Part # Description List Price Price
24578467 Trans-Axle
SONIC; 5 SPD. TRANS
$1,931.63 $1,699.83
Part # Description List Price Price
55598411 Trans-Axle1
SONIC; 6 SPD. TRANS; W/ O RS MODEL
$1,931.63 $1,699.83
Tweaterben
New member
Sam thing here
Hey guys, haven't touched base on here in a while. I've been going through the same thing as everyone. Just moved to Minnesota, and the cold weather is making my transmission SCREAM! unfortunately I didn't notice the sound until 2 months before the warranty was up, and didn't bring it in until 2 months after the warranty expired. It's almost as if Chevy designed this transmission to die right around warranty time. Once I spend the $3K to replace this thing after it goes to complete failure, I will sell this bowtie and do something I thought I would never do. Switch to Honda/Toyota/Mazda! Bad design Chevy, very sad this thing was produced.
Hey guys, haven't touched base on here in a while. I've been going through the same thing as everyone. Just moved to Minnesota, and the cold weather is making my transmission SCREAM! unfortunately I didn't notice the sound until 2 months before the warranty was up, and didn't bring it in until 2 months after the warranty expired. It's almost as if Chevy designed this transmission to die right around warranty time. Once I spend the $3K to replace this thing after it goes to complete failure, I will sell this bowtie and do something I thought I would never do. Switch to Honda/Toyota/Mazda! Bad design Chevy, very sad this thing was produced.
Tweaterben
New member
Checked into a replacement. After labor and parts, your looking at around $2,900-$3,200 depending on where you bring it. Or $1,700-$2,000 in parts if you do it yourself.
Bro. I did the whole thing myself for $350...
Tweaterben
New member
How on gods green earth did you manage to install a new transmission for that cheap? Legally
Okay so I just got done with a whole ordeal, but I got mine repaired, not replaced.
2012 Sonic 1.4L Turbo MT
I'll try to sum it up briefly:
- I notice the whine on a cold day about a year ago now. My car was probably around 85k miles at that point. I don't think much of it.
- I research the whine a bit, mostly reading through this thread.
- Take it to the dealer for the whine along with some other issues. They diagnose it as a whistling coming from my roof rack. Whatever, they replaced my tires which needed replacing, maybe it was just the tires. New tires are great, whine is still there.
- Ask them to check it again a few months later and making sure to insist that "Yes, the roof rack does whistle; This is a whine/grind coming from below, not above". They figure out there is noise coming from the transmission now. They won't work on the transmission, they will only replace it. I don't want to pay for a new transmission.
- I seek help elsewhere, I spend more time researching. Probably call around to about 10-12 different shops, many of which say transmission in the name. Everyone gives me noncommital answers and "uhhh I don't know if we have the tooling for that". Finally find a guy that says it sounds like pretty routine work. Awesome!
- Car is in the shop of for a couple of weeks when he tells me none of his sources can get their hands on the bearings he needs to replace my worn out ones - he's checked with a bunch of parts shops and the dealers themselves. He doesn't know what else to do but swap it out completely just like the dealer was going to do.
-In the mean time I had found two important items. A Cruze owner detailing how he replaced these bearings himself:
https://www.cruzetalk.com/forum/10-gen1-powertrain/205442-m32-gearbox-bearing-fix.html
In which he links to this page:
https://www.onestopgearboxshop.com/products/m67?variant=3974386691
- I sent these two links with some kind words of appreciation to my mechanic to see if he'd please look into them before throwing in the towel. I thought he might dismiss me as an annoying customer, but he looked into it and... it all worked!
- Car is back, it's quiet. I paid about $300 plus labor instead of $1900 plus labor. I'm happy.
Not sure if this is allowed, but if you're in the Seattle area and are having this problem, Tony at Kirkland Transmission is now familiar with it and can help you out.
https://www.kirklandtransmission.com
2012 Sonic 1.4L Turbo MT
I'll try to sum it up briefly:
- I notice the whine on a cold day about a year ago now. My car was probably around 85k miles at that point. I don't think much of it.
- I research the whine a bit, mostly reading through this thread.
- Take it to the dealer for the whine along with some other issues. They diagnose it as a whistling coming from my roof rack. Whatever, they replaced my tires which needed replacing, maybe it was just the tires. New tires are great, whine is still there.
- Ask them to check it again a few months later and making sure to insist that "Yes, the roof rack does whistle; This is a whine/grind coming from below, not above". They figure out there is noise coming from the transmission now. They won't work on the transmission, they will only replace it. I don't want to pay for a new transmission.
- I seek help elsewhere, I spend more time researching. Probably call around to about 10-12 different shops, many of which say transmission in the name. Everyone gives me noncommital answers and "uhhh I don't know if we have the tooling for that". Finally find a guy that says it sounds like pretty routine work. Awesome!
- Car is in the shop of for a couple of weeks when he tells me none of his sources can get their hands on the bearings he needs to replace my worn out ones - he's checked with a bunch of parts shops and the dealers themselves. He doesn't know what else to do but swap it out completely just like the dealer was going to do.
-In the mean time I had found two important items. A Cruze owner detailing how he replaced these bearings himself:
https://www.cruzetalk.com/forum/10-gen1-powertrain/205442-m32-gearbox-bearing-fix.html
In which he links to this page:
https://www.onestopgearboxshop.com/products/m67?variant=3974386691
- I sent these two links with some kind words of appreciation to my mechanic to see if he'd please look into them before throwing in the towel. I thought he might dismiss me as an annoying customer, but he looked into it and... it all worked!
- Car is back, it's quiet. I paid about $300 plus labor instead of $1900 plus labor. I'm happy.
Not sure if this is allowed, but if you're in the Seattle area and are having this problem, Tony at Kirkland Transmission is now familiar with it and can help you out.
https://www.kirklandtransmission.com
Simple. You buy a used transmission. Anything above 2014 is when Chevy updated and revised the internal bearings as well as the fill specs on the transmission.
So a transmission off a junked car around me in Ohio is anywhere from $250-500 depending on mileage and year.
My most recent swap I went to the MZ0 short ratio from the Cruze. Any of the Cruze transmissions swap into the Sonic, at the penalty of different ratios and fuel economy. So that opens the selections.
Getting back on track, purchased an MZ0 for $350 from a 2016 Cruze with less than 50k miles. Bought a new clutch - GM Performance for $287 with tax - already had a transmission jack. The only bolts that are disposable are the steering rack, control arm ball joints, and lower transmission mount. So i got those online as well.
The labor is not that bad honestly. Hardest part is getting the transmission out and back in. The rest is just a little patience and following the torque specs. With two people it can be a job done in one weekend day. The guide to get it out is on the forums. I need to make an addendum commentary video to illustrate some extra talking points that weren't elaborated on.
Upon installing the new transmission, I drained and filled the fluid with Amsoil Synchromesh GL-4. Which I purchased at a local dealer for $45.
Prior to doing the MZ0 swap I originally reinstalled an MZ4 which is the stock one. I picked up one of those for $275, didn't do a new clutch. With bolts and fluid it put me up at around $350
Yeah bearing rebuilds is a common thing that the guys in the UK do with theirs. They were the first ones to experience the issue since they received the M32 in the their Astra's before us. The issue is the price in labor. If you go to a shop getting the transmission out to get the bearings in can jack up the costs.
Also, early models did not receive an updated end case. The revised one has extra oil lanes and cooling fins to radiate extra heat from the transmission. So rebuilding an old revision will require a new end case as well.
Last edited:
Yeah, we've got what, the Sonic and the Cruz with the M32 over here? Two car models. From what I've seen there's probably two dozen cars across the pond with this gearbox.
I'm wishing I would have asked him to do the whole endcase upgrade, but alas I did not. We'll see if I can make it another 100k on the lousy 2012 endcase.
I'm not a mechanic, but after going through all this and all the research I poured into it I feel like I'm an M32 expert now lol :blankface:
14DrgGreen
New member
Hello all,
New to the forum. Great info here.
HELP!
Bought a Dragon Green Sonic RS new in 2014. Now has 68K miles and the transmission whine is awful.
I can't find a transmission shop in the SF bay area who will do the bearing replace. I have already bought the bearing set for the M32 as described here.
Can anyone recommend a good mechanic/shop?
Thanks for your help.
New to the forum. Great info here.
HELP!
Bought a Dragon Green Sonic RS new in 2014. Now has 68K miles and the transmission whine is awful.
I can't find a transmission shop in the SF bay area who will do the bearing replace. I have already bought the bearing set for the M32 as described here.
Can anyone recommend a good mechanic/shop?
Thanks for your help.
Hi all - I'm new. My 2020 RS will be about as modded as ZZP can get it after this next visit in June. We will so the cam and 3 in pipe. It's already got the Z04 turbo, beefed intercooler, ported intake, E85 injectors, sway bar and coilovers. I think it can ultimately dyno @230hp(ish).Honestly I never thought I would dig this car as much as I do. Alas, however - it is the GT40 auto trans and a manual swap is more hassle than I'm up for.
So - where are we on beefing and adding performance to these stock auto trans's - and/or a swap to the 6T45 - w/or w/out then mods to that? Help - thoughts - insight.
So - where are we on beefing and adding performance to these stock auto trans's - and/or a swap to the 6T45 - w/or w/out then mods to that? Help - thoughts - insight.