Piston Slap: The Importance of Servicing Your Car’s Transmission Fluid
Ron writes:
Sajeev,
Would the recall/lawsuit you previously mentioned be applicable to 2020 Malibus also? My girlfriend’s appears to have the same problem with hers.
Sajeev answers:
Sorry, no—the Malibu has a totally different transmission design. That episode of Piston Slap was about a transmission (for rear-wheel-drive vehicles) but this Malibu has a transaxle (for front-wheel-drive vehicles). Transmissions and transaxles can have interchangeable parts that can fail concurrently, but that’s unlikely. There could be a known issue with your transmission that has not risen to the level of a recall, but I didn’t see one on the internet. I recommend visiting the service department of a GM dealer to learn more about that, but I suspect your concern comes from worn-out transmission fluid in a four-year-old car.
I’m sticking with the transmission fluid as the problem here, but there’s another curveball coming our way: Malibus with the 1.5-liter engine came with a continuously variable transmission (CVT). These CVTs lack traditional gears in the gearbox, so here’s a quick visualization:
Okay, back to the issue of servicing your transmission fluid. The going theory on those GM transmissions from the previous Piston Slap is that the original fluid didn’t play well with moisture. That might apply to the Malibu, but remember all transmission fluid wears out over time. You could have accumulated a lot of miles in tough conditions since the vehicle rolled off the assembly line in 2020, and it may simply be time for a fluid-and-filter service.
There are times when changing transaxle fluid in a used car is a very bad idea, but this vehicle is too new to have that problem. (Hopefully.) When doing the service, make sure the shop uses the correct fluid. See the owner’s manual below:
CVTs always require a specific type of fluid, and putting in “traditional” automatic trans fluid will shorten the life of the transmission considerably. Sometimes there are tricks to remove as much of the old fluid as possible, and finding a shop that checks for this could be a good idea. But if you want to DIY this, there’s real value in doing transmission fluid changes in succession to flush out all the old fluid.
And at some point you also change the transmission filter, and this video suggests doing the filter change after the third oil change. Sounds fair, and we are lucky enough to see how to do this filter change in another video:
So do check with your dealer about any potential problems with your transmission, but I suspect this is a case of needing fresh transmission fluid. What say you, Hagerty Community?
Rule number 1 avoid all CVT transmissions by every mfg. they are all crap.
Yup….
I can’t say I have ever had one that I enjoyed. Tolerated is the best I could do in regards to a CVT. I’ve never owned a car with one, just had loaners/rentals with it and never liked it.
Rule Number 2, avoid all CVT transmissions from all manufacturers, they are all crap.
Rule Number 3, Adhere to rules 1 and 2 as stated by hyperv6 and John.
We had a Honda Ridgeline 2019 with the six speed automatic. After five years, transmission was acting as though it was slipping going up slight hills. We took to dealer who recommended changing transmission fluid, after the change, problem went away. Because there are reports of six speed automatic transmission failures, we got scared. We replaced for my wife with a new 2025 Pilot. I still think changing the trans fluid makes sense after 4-5 years or 60,000 miles.
I think your fears got the best of you. If you take transmission fluid in modern transmissions to the end of its life, you’ll experience slight slipping or shuddering under certain conditions. If you change the fluid in reasonably short order, your transmission will still be fine. One downside of easy access to knowledge (such as on the Internet) is understanding when reports of issues are significant enough to matter or merely a few voices getting a lot of attention.
“One downside of easy access to knowledge (such as on the Internet) is understanding when reports of issues are significant enough to matter or merely a few voices getting a lot of attention.” That is the entire internet in a nutshell – it virtually does not matter what the subject is whether its cars, medical advice, fixing something in the house, politics or ANYTHING else.
The truth is there are many shudder issues on todays transmissions.
We used to only have a couple fluids and today many take specific blends. The transmissions are made more complex with lighter parts. The days of the old Turbo 400 are long gone.
Other factors too are some of todays radiators cool transmission fluids and some have been known to take on water due to leaks like at VW and Audi.
Be aware it is not like it used to be in changing too. Most take a machine that flushes the unit and it replaces the fluid at running temp.
My Corvette has to be checked at temp. The joke is if you remove the plug and get hit in the face with hot fluid it is full. No dipstick on many units anymore. read the manual to make sure what you need to do and how to do it.
The old wive’s tail I always heard was If a car reaches 75000 miles never having the tranny fluid changed, don’t do it now because you’ll stir up all the sediment thereby trashing the tranny in short order. Seeing how people rarely change it, every used car I’ve bought I never messed with it. The only time I was forced to was with my 1997 GMC box truck. When we had that gas crunch in the early 00’s, my truck sat pretty much the entire year. When I finally drove it the one cooling line rusted out and leaked. So I had it replaced and of course the filter and fluid had to be replaced. It was never the same…
In every transmission I’ve ever owned, serviced or have seen the pan must be removed for a filter replacement. When doing so the pan is removed and cleaned where the sediment gathers, you clean it all out and install with a new filter an new fluid and no trashing will occur. A small correction – it is wives tale, like a story, not her actual… 🙂
I change my two (2) Acura’s 2012 RDX and 2001CL-S every 30,000 miles, which is really changing about 4 quarts (about 1/2) as no access to the torque convertor. The 2001 CL-S had transmission changed by recall several years ago. It does get a little shudder to it at about that 30,000 mile change. I add shudder fixx which really helps and several years back had to replace some trans. solenoids which helps a 3/4 shift issue.
On my 1987 MB 560SL I have drained twice and replaced filter (8.5 quarts as can drain torque convertor) in the 30,000 miles I have owned it. Really helped changing it and shifts seemed more positive but could be my imagination.
In our long string of Volvo 240s with AW transmissions I have always changed fluid with the (hot) engine running. Dis-connect the cooler line and add a catch-hose, and refill as it pumps out. Two gallons in, two gallons out – simple. I’m sure I’ll be told that’s wrong, but it has worked for many (40?) years for us.
I have had two transmissions fail after changing the well used (high mileage) vehicle’s trans fluid.
I have a firm rule of not messing with transmission fluid unless there is a driver to do so. If it is nice and pink, leave it alone. If it is starting to get a little dark, consider changing it. If it is acting funny and starting to get dark, transmission is already toast.
I have proven that wrong at least 4 times on antique cars with unknown service histories. For me the fluid can be changed IF the gearbox has less than 100,000 miles and its behavior is messed up enough to cause performance issues at speed. (like not downshifting). Fluid servicing is a crapshoot on older vehicles, but sometimes you need to take that risk.
For modern vehicles? Read forum posts/Facebook groups/Reddit and see what internal flaws might be exacerbated by a fluid change at your specific mileage. But I bet the 100k mile mark will apply there too.
The reason I say that is because there are a lot of ways a fluid change can go wrong. Filter/strainers tend to have orings or seals that are very finicky and are easily nicked. Pan gaskets are very leak-prone once disturbed. I have seen a lot of people toast transmissions as a result of fluid changes. I have gone north of 200K miles without touching transmission fluid.
And those are very good points. I remember one of my “risky” fluid changes included installing a new pan and gasket, and it initially leaked even with those new parts.
Another thing to consider are the pressurized fluid flushing machines: those are probably a bad idea for maintenance deferred gearboxes, as they blow out everything and can cause more internal problems than just a pan drop and fluid/filter change. Or so I’ve heard on multiple occasions.
I feel like pressurized flush machines are a result of people overthinking the process. This would apply to any fluid–transmission, antifreeze/coolant, oil, whatever. Whatever doesn’t come out from a normal dump-and-fill probably isn’t going anywhere during normal operation. Meanwhile, if you’ve replaced all of the old fluid that will come out, you’re still much better off.
It’s like that ductwork cleaning for your house. If the dust is in the ducts, it wasn’t going anywhere! It’s just the *idea* of things not being perfect that gets people to do stuff that doesn’t need to be done.
l doubt that ALL CTVs are crap. Don’t GOOD manufacturers work to improve things that are a trouble point?
Corollas are still long-term reliable vehicles, sell at a premium on used car lots, and they have had CVTs for years. I’ve had a couple of newer Nissans and have not had a problem. They predictably improved their CVT! And l get GREAT gas mileage in my Murano – significantly better than the EPA figures show! l also like their smoothness – no gear “hunting” as in a significant number of “regular” automatics.
l plan to change fluid at about 40,000 miles for the first time. My neighbor across the street has an older Altima with about 200,000 miles on it – and the transmission still transmits!
Notice nobody complained about the Subaru, maybe they know something the others haven’t learned yet.
Automatic Transmission. Hmm.
1959 Jeep FC 150: 3Speed
1971 Chevy K-20: 4Speed
2003 BMW 325XI touring: 5Speed
1999 Porsche 911 Cabriolet 6speed.
I and my wife are with you on the 3 pedal arrangement.
1970 Impala: 4 speed
2005 Dodge Ram 2500: 5 speed
2010 Camaro 2SS: 6 speed
2017 Honda Accord Coupe: 6 speed. Having 6 cylinders that car is very quick.
2017 Chevrolet SS: 6 speed
What, no 3-on-the-tree? ;<)
Power glide; Turbo 400/M 40; Turbo 350; 700R4; 4L60/4L80;Allison; 2 10 speeds on service currently. All got serviced q50K- only failure was the 700R4-3/4 T PU(overheating kills them).Change the fluid! Routine maintenance…
Everyone should aspire to drive a manual transmission vehicle. Wonderfully connected with driving instead of just tromping on the throttle or flipping paddles. Cheaper and less problematic. Also major enjoyment over any automatic or cvt.
Many of today’s auto trannys are SEALED… meaning no way to check the fluid level. The manufacturers specify a fluid change interval, from 40K to 80K. I found that out the hard way! At about 80K the trans in my 2014 Escape failed. Had to be replaced at just under $8K! The car was only worth a little over that, but I replaced the trans anyway. It was still cheaper than a car payment or replacement — I’d just have to drive it 2-3 more years to get my money’s worth. I assumed the oil change places were checking and topping off the trans as needed — as they did with all the other fluids. No way to check the fluid level easily, and it’s difficult to get to the fill location. You can’t 100% seal anything with rotating shafts coming out of it! There will be minimal loss, but SOME. Over time and miles you can eventually lose enough to have issues without topping off occasionally. Mine did around 80K miles — trans started slipping, only solution was a rebuild. The filter is in the middle of the trans and requires removal (splitting the case!) to replace. It’s typically back flushed when changing the fluid. So look at your car’s owners manual and see if it’s a sealed trans, and if it is have the fluid changed by the interval given! There is (was) a class action lawsuit against Ford for those transmissions. I was contacted by the law firm, but declined to join. For starters it was my fault the trans failed when the change interval is 40K miles and I’d gone twice that without changing. The second reason is that these (usually) frivolous lawsuits just drive car prices higher. If the trans had failed for unknown reasons or at a much lower mileage than the change interval I may have joined the lawsuit though.