Sportback 9T50 9-speed Auto - Conversation & Questions

[BradyB0225]

Here is some more specific info to share regarding the FWD 9-speed (9T50) slushbox. GM Hydra-Matic 9T50 9-Speed Automatic Transmission

I am loving this transmission, GM's engineering is stellar when they want to actually make something good.

For example, the accumulator which is used to restart the engine during auto-stop is pretty cool. I guess I don't have to be worried about the starter wearing out sooner as it's actually not doing the starting during stop/start.

I also love the ability to coast when coming off the gas, the car coasts forever with the transmission's ability to freewheel. This was one of the last advantages of driving with a manual transmission. Does anybody else notice that it feels like the transmission is in neutral when coming off the gas?
I don't mind using the brakes a bit more to slow down as I've often thought that I would much rather replace brake pads rather than transmission clutch packs.

I do have a question regarding an FWD limited-slip as I am not seeing that mentioned anywhere. My Regal seems to lose traction with both front wheels spinning rather than a one-tire-fire. Does my car have a limited-slip or is it simply well designed with equal-length half-shafts to prevent torque steer? With the snow I've experienced so far, the car seems to do really well maintaining drive traction with just FWD.

 

[ZB Commodore Owner]

I can't answer your question about the LSD as my model is fitted with adaptive AWD. As soon as one wheel loses traction power is removed from that wheel.

One feature I like is the downshift feature, giving some engine braking as you slow for a tight corner. This also means the gearbox is already in the right gear to accelerate away.

The gear changes are pretty snappy, not as crisp as the dual clutch (DSG) set up, but still very good.

 

[PrincipalDan]

I'm pretty positive there's no LSD (mechanical or electronic). GM has been working pretty hard to engineer out torque steer for the last several years. On the 2nd gen Lacrosse they had an optional "Hyper Strut" Suspension designed just to quell torque steer. But usually a company like GM starts to allow those new technologies to trickle down into other cars and sometimes they don't really advertise that they did.

GM does know how to make a FWD car that has good handling compared to other FWD cars.

 

[ZB Commodore Owner]

In the Australasian market Holden fitted the hyperstrut to all the AWD models which also happened to be all of the 3.6 V6 models (Sportback or Sportwagon).

In our market the 2.0 litre turbo engine, with the exception of one model which was special order only, was only used for the base model vehicles (FWD no AWD and other differences like tyre sizes, no heated seats, no sports mode, etc). There is no mention of any LSD options for any of the models sold here.

Based on what was sold in our market I suspect the hyperstrut is fitted to the Regal GS but probably not the Tour X (which I understand is only the 2.0L).

Also the rear suspension is different. All of the V6 models have a 5 link set up whereas the 4 cylinder models have a 4 link set up. I suspect the 5 link set up is related to AWD being fitted so if you have AWD on a 2.0L model then it may have the 5 link rear suspension.

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[powermax]

By far one of the best conventional automatic transmission I've ever driven. My only complaint is that there is barely any difference between 2nd and 3rd gear.

 

[Jack GS]

My only complaint is that there is barely any difference between 2nd and 3rd gear.

I've noticed that too. Makes shifting manually through the gears smoothly next to impossible when the needle is still pegged on the redline.

This has been my biggest argument against the need for paddle shifters. Don't get me wrong, I still think they'd have been nice to have, but I'm not sure how much I'd actually use them given the close ratios of the trans.

 

[shs92645]

I’m very happy with the transmission in my GS. A huge step above the 6speed auto that was in my ‘13 GS. When you have the opportunity to step on it leaving a red light the shifts are very impressive. I personally have never had any use for paddle shifters but it was definitely a mistake not to include them as it turned out to be about the only thing reviewers could complain about.

 

[BradyB0225]

I’m very happy with the transmission in my GS. A huge step above the 6speed auto that was in my ‘13 GS. When you have the opportunity to step on it leaving a red light the shifts are very impressive. I personally have never had any use for paddle shifters but it was definitely a mistake not to include them as it turned out to be about the only thing reviewers could complain about.

If I understand correctly, the GS uses a slightly beefier version, the 9T65, probably set up to handle AWD. Too bad they didn't use it with the 2.0L AWD TourX. I bet the decrease in performance between the Euro wagons and the TourX is due to the 8 speed/9 speed.

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[Jack GS]

If I understand correctly, the GS uses a slightly beefier version, the 9T65, probably set up to handle AWD. Too bad they didn't use it with the 2.0L AWD TourX. I bet the decrease in performance between the Euro wagons and the TourX is due to the 8 speed/9 speed.

The FWD Sportback and GS share the same 9T50 transmission. The only difference is the option code is M3D for the Sportback and M3T for the GS. I am guessing the difference in option codes is due to the engine it's being mated to and possibly differences within the TCM.

 

[ready2fly]

I do also love our 9-speed transmission. It felt a bit jerky at the beginning, but then I learned to drive it easy and it just flows. Acceleration is silky smooth. Many other components make our cars smooth as well. Tires do make a big difference since I tried other tires, but returned to ProContact TX.

Owners manual calls for 45,000 miles transmission fluid change under "Severe" driving conditions. I don't do any severe driving, just highway commute to work, but I will be changing my trans fluid. I just don't believe in lifetime transmission fluids.

 

[Jack GS]

Correction to Post #9

The GS does not use the 9T50 transmission. It does in fact use the 9T60.

I have been seeing contradictory reports of which transmission is actually used. Some documents say the GS uses the 9T50, others the 9T60, and there are even documents stating it uses the 9T50 and 9T60 depending on where you look...

I dug up a service bulletin used to introduce technicians to ALL features of the new Regal. In this document, it is clearly stated which engine/transmission is used in each model.


Many other feature descriptions of the Regal are also included in this document. See it here:
Get to Know Your 2018+ Regal: New Model Features Service Bulletin

 

[1500cc]

Very interesting. I didn't know that the transmission did the restarting part of the automatic start/stop. Although I always wondered why the sound and speed of the car starting seemed different when doing a 'manual' start versus the auto start/stop. I guess this would explain it.

I wonder if this helps ease the concerns of those who hate auto start/stop mainly because of the fear it'll prematurely wear out the starter.

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[garbageguy]

Very interesting. I didn't know that the transmission did the restarting part of the automatic start/stop. Although I always wondered why the sound and speed of the car starting seemed different when doing a 'manual' start versus the auto start/stop. I guess this would explain it.

I wonder if this helps ease the concerns of those who hate auto start/stop mainly because of the fear it'll prematurely wear out the starter.

+1 on that, very intresting. Can anyone confirm the transmission does the starting part of the ASS?

 

[RTF]

Does anyone know anyway to find the part number for the torque converter for the GS 9T60?

I unfortunately think I’m going to need mine replaced at some point as I’m already getting a slight shudder. The dealership has been great to work with thus, but haven’t been able to “duplicate” it yet.

 

[Jack GS]

Does anyone know anyway to find the part number for the torque converter for the GS 9T60?

I unfortunately think I’m going to need mine replaced at some point as I’m already getting a slight shudder. The dealership has been great to work with thus, but haven’t been able to “duplicate” it yet.

I searched on the GM Genuine Parts website and could only find a part number for the entire transmission assembly. They list torque converters, so you may just want to contact them directly through the website.

While browsing their ecatalog for transmission parts, this is what the search returns:

Coming from GM Genuine Parts, I would expect the transmission designation to be correct. Either our search for enlightenment on this topic is not yet over, or the GM website is incorrect. I will assume the latter...

 

[Jack GS]

From my understanding, the starter is still solely responsible for starting the engine. The accumulators are used to charge the hydraulic pressure within the transmission in order to enhance the responsiveness and smoothness of the launch. TSB 17-NA-376 describes the changes made to the starter and electrical system required for the increased starter cycling at the end of Page 10. I will take a section of that paragraph here:

To support the increased number of engine starts, the starter motor is upgraded with a high performance electric motor and a stronger pinion engagement mechanism with reduced noise levels. Along with the upgraded starter motor, advanced battery technology is required to ensure the vehicles battery can handle the frequent charge and discharge cycles common with Stop/Start operation.​

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There is no mention of the accumulators within the transmission starting the engine. I did find this video on the subject by Borg Warner. I cannot say with certainty that this is how our accumulators are designed and implemented, but it would make sense that any Stop/Start system would utilize the technology to some extent.

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