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Catastrophic Transmission Failure 2021 Ascent 10k Miles

29K views 167 replies 38 participants last post by  Robert.Mauro 
#1 · (Edited)
Our first Subaru, a 2017 3.6r Outback, made us realize why people speak so highly of the brand. The car never gave us any issues, tore thru mountain passes, snow banks, and would perform like a champ off road. So when the time came to replace a second vehicle we wasted no time shopping other brands and purchased a 2021 Ascent Touring back in December of 2020. Once we took ownership of the vehicle we installed a 1.5" lift kit from Anderson Design Fabrication, changed wheels and tires, added primitive skid plates underneath the vehicle, as well as a rally light bar along with rally lights.

Our first indication our Ascent was experiencing transmission issues was back in May. We live in Los Angeles and own a small teardrop trailer that we had been pulling with the ascent. On several occasions, all of which occurred when climbing mountain passes, the cvt fluid overheating light had come on requiring us to pull off to the side of the highway in order for the fluid to cool prior to resuming our travels. Upon returning to town I brought the vehicle in for service and advised the Subaru service department of the issue and asked that they look in to the cause. Service department informed me that everything checked out and they did not see an issue with the vehicle.

Wednesday a week ago, myself, wife and five year old had the ascent packed with camping gear and headed north for a weekend up in Big Sur. It was mid afternoon on a relatively cool day as we started climbing the grapevine, a notoriously steep climb out of Los Angeles that takes you up central California. As the vehicle was climbing the pass I felt the transmission slip as it aggressively shifted gears (another complaint I have of the vehicle due to its small engine). Within two minutes of that slip all three of us hear a loud boom, my eyes immediately look thru rear view mirror to see a cloud of smoke and debris bouncing across the freeway that clearly came from our vehicle. We lost complete control over the vehicle and coasted while making our way to the shoulder.

Subaru road side assistance was unable to get us a tow truck in a reasonable time frame so I used my AAA membership to have us towed back to our house so I could transfer our gear to the outback and get us out of town for the weekend. Once we returned home I had the Ascent towed in to our Subaru dealer who now has the vehicle and awaiting an engineer from NA Subaru to inspect the, as the service manager classified it as a, catastrophic transmission failure. From what they informed me after inspecting the vehicle was the CVT chain broke off and literally blew a hole thru the transmission casing (photos attached). He also stated that after all his years in service he has never seen anything like this occur.

The first thing my wife asked was, did you tell him we want a new car?

Now I know the service manager is not the person to make that decision, but wondering if there have been any other cases where this has occurred in a vehicle less than a year old with less than 12k miles. Do I really want to have our vehicle repaired? We no longer want the vehicle and plan to sell it regardless once the repairs are made.

UPDATE 11/3: Dealer was instructed to wait on repairs for an engineer from SOA to visit and inspect vehicle. This afternoon SOA authorized the replacement of entire Transmission, and the Transmission Control Module.
 

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#3 ·
I don't think I've ever heard of a Subaru CVT literally breaking a chain. It's probably truly a one in a million failure.
^^ This. And the TR690 employed in the Ascent has been in use for twelve years. Sad you had this happen, but I'm sure you'll get taken care of. I doubt that will include a new vehicle, however, but you can certainly ask!
 
#7 ·
I can definitely understand the impetus to sell, after such an experience.

We're a leasing family. I love working on my car(s), but with our current lifestyle, an enjoyable afternoon for me is a back-to-back set of pit-stops for fluids changes and tire/wheel changes on our vehicles: I just don't have the time to really wrench.

With the fact that we lease, in-mind, here's the tale of my wife's '09 Forester XT, which has a picture of our service invoice for authentication. :)


After her heart transplant, she performed as-new, and she was a faithful companion for our family on several long road-trips. She never spent another day in the shop, after that, and finished-out her 3-year stint until we replaced her with a '13 FXT Touring.

I don't believe that it's my place to encourage you to give your current vehicle another chance - but at the same time, I also don't think it inappropriate for me to discourage you from not doing so. More than likely, this is just one of those freak occurrences.

I'm willing to bet that unless your dealership is an awful one, that both they as well as SoA will make-right by you. Our dealership certainly rolled out the red carpet for us, with our '09 FXT.
 
#8 ·
Our first Subaru, a 2017 3.6r Outback, made us realize why people speak so highly of the brand. The car never gave us any issues, tore thru mountain passes, snow banks, and would perform like a champ off road. So when the time came to replace a second vehicle we wasted no time shopping other brands and purchased a 2021 Ascent Touring back in December of 2020. Once we took ownership of the vehicle we installed a 1.5" lift kit from Anderson Design Fabrication, changed wheels and tires, added primitive skid plates underneath the vehicle, as well as a rally light bar along with rally lights.

Our first indication our Ascent was experiencing transmission issues was back in May. We live in Los Angeles and own a small teardrop trailer that we had been pulling with the ascent. On several occasions, all of which occurred when climbing mountain passes, the cvt fluid overheating light had come on requiring us to pull off to the side of the highway in order for the fluid to cool prior to resuming our travels. Upon returning to town I brought the vehicle in for service and advised the Subaru service department of the issue and asked that they look in to the cause. Service department informed me that everything checked out and they did not see an issue with the vehicle.

Wednesday a week ago, myself, wife and five year old had the ascent packed with camping gear and headed north for a weekend up in Big Sur. It was mid afternoon on a relatively cool day as we started climbing the grapevine, a notoriously steep climb out of Los Angeles that takes you up central California. As the vehicle was climbing the pass I felt the transmission slip as it aggressively shifted gears (another complaint I have of the vehicle due to its small engine). Within two minutes of that slip all three of us hear a loud boom, my eyes immediately look thru rear view mirror to see a cloud of smoke and debris bouncing across the freeway that clearly came from our vehicle. We lost complete control over the vehicle and coasted while making our way to the shoulder.

Subaru road side assistance was unable to get us a tow truck in a reasonable time frame so I used my AAA membership to have us towed back to our house so I could transfer our gear to the outback and get us out of town for the weekend. Once we returned home I had the Ascent towed in to our Subaru dealer who now has the vehicle and awaiting an engineer from NA Subaru to inspect the, as the service manager classified it as a, catastrophic transmission failure. From what they informed me after inspecting the vehicle was the CVT chain broke off and literally blew a hole thru the transmission casing (photos attached). He also stated that after all his years in service he has never seen anything like this occur.

The first thing my wife asked was, did you tell him we want a new car?

Now I know the service manager is not the person to make that decision, but wondering if there have been any other cases where this has occurred in a vehicle less than a year old with less than 12k miles. Do I really want to have our vehicle repaired? We no longer want the vehicle and plan to sell it regardless once the repairs are made.
I know this doesn't answer the question, but I was told that Subaru has a 100,000 mile guarantee on the CVT .... IF it has not been tampered with by anyone including a Subaru dealer. I don't know about that last part, but they want to get the entire transmission intact for inspection. If you take it to a transmission place after, say, 50K to have it serviced & they open the case, then it voids the warranty. That is what I've been told anyhow.

I know you haven't had anything done to the CVT so they will replace it with a completely new unit - not a rebuild or a repair.
 
#10 ·
Boiling this down to the tldr version:

You towed something, the AT Temp light came on. Dealer inspected, showed no issues.

Subsequently, you travelled up the Gravevine, and the transmission had a catastrophic failure.

Your ask: Is asking for a new vehicle reasonable?

My hot take
: No. The entire vehicle didn't fail, the transmission did. The transmission, like many components, can be repaired or replaced. Unless there is some sort of direct integration of the transmission into the unibody chassis that's unique to the Ascent, there's no reason to issue a new vehicle.

Caveat: You may have diminished value in your vehicle because of this replacement when it to selling the vehicle. That is to say, if I am a buyer and I am comparing CARFAX reports, I'm going to pick one that hasn't had a major issue vs. one that has.
 
#15 ·
Caveat: You may have diminished value in your vehicle because of this replacement when it to selling the vehicle. That is to say, if I am a buyer and I am comparing CARFAX reports, I'm going to pick one that hasn't had a major issue vs. one that has.
Possible that a nice email or call to SoA will have a goodwill measure given to the OP. :)
 
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#14 ·
Yeah, that's gotta be a very odd, very rare failure.

I did 35k miles in my 2019 Ascent, with over 5,000 miles of it towing at/near the limit of 5,000lbs and in the mountains. I also offroaded and basically always drove it hard. No issues.

New tranny and you should be good to go. Also SOA will stand behind the new tranny too.
 
#16 · (Edited)
Wondering if your lift kit and wheel / tire upgrade may have affected the geometry and/or function of the Symetrical AWD system? Also, did the skid plate in any way restrict airflow to the trans, which when combined with towing, may have contributed to its overheating? Only mentioning these issues so you can be prepared should the dealer decide to challenge the warranty claim. Don’t have enough facts to really comment other than to raise the questions. For your sake, hoping not an issue!
 
#19 ·
My buddy used to work at a Subaru dealer and they would do whole CVT swaps for such minor things any other manufacturer would just repair. Part of that was around Subaru not letting them repair the CVTs. I think if I had a one time major failure that resulted in a CVT swap I'd keep it. Now, if it has reoccurring issues (related or otherwise) then I'd looking at ditching it.

I'm not sure I can agree with wanting a whole new car in this example.
 
#20 ·
If it was mine I would just have Subaru install the new transmission under warranty and then keep on driving it for another 10 years or so.... Assuming they can source a new transmission in a reasonable amount of time.
 
#22 ·
After this experience, I would have the new transmission installed per the warranty and request SoA to comp a 10/100/0 Gold Plus extended warranty to allay any doubts re future reliability issues. I personally don't believe a new car is a reasonable ask. Parts are man-made and can fail, whether a small item like a starter or a big one like the engine or transmission. Hyundai/Kia recently had to replace thousands of the Theta II engines due to faulty rod bearing failures. They also extended a lifetime, unlimited mile warranty to all owners of this series engine, mostly for consumer confidence & PR.

I hope all works out well for you.
 
#23 ·
It is nice to read all of the reasonable and thoughtful responses to the OP. An additional concern that I have is the prevalence of vehicle owners, Subaru and otherwise, who think that the payload and towing ratings for vehicles are unaffected by suspension lifts/drops and increased tire/wheel mass.

I doubt theses mods had much to do with the faulty transmission, but towing up and down mountain passes with these mods does not seem wise.

Am I being unreasonable? I have a decent amount of experience towing with SUVs and full-size trucks. The only real upgrades I found justifiable are replacing P rated tires with LT and stock brake pads with good quality ceramic ones (if not already equipped).
 
#24 · (Edited)
Wow, that's horrible! The good news is, in all my time learning about and following the TR690's 12 year history, you're literally the second verified chain failure (plus one unverified guess by another person) I've ever seen. That chain is literally the strongest, beefiest, highest-torque-capable CVT belt or chain mechanism put into any production car. So, I definitely think this is a one off.

I am wondering if it was low on CVT fluid or had the wrong stuff in there (eg: Jiffy Lube messed up). Otherwise, it's a freak situation that's rarely happened in all of the years the TR690 has been in service.

Once they swap the entire TR690, you'll be good as new (but remember, you have a 1,000 mile break-in to perform, with no towing during that time). I'd be very much fine with them swapping that TR690 for a new one, and dealing with any damage from bits of the CVT being ejected. I wouldn't be surprised if they offered you an extended warranty either. You still, of course, need to do what makes YOU feel comfortable, regardless of what would make ME feel comfortable. 😉

Please keep us posted.
 
#31 ·
I'm not sure that it is appropriate to say that you need to find a better qualified tow vehicle. Towing specifications are provided for a reason and this applies to any vehicle. As long as you don't exceed the manufacture's maximum towing capacity, the payload capacity of the vehicle and maximum tongue weight you should have complete confidence that the vehicle you have selected is suitable. If you know that you are exceeding the limits and something fails that's on you. If you find that your towing requirements have changed and you need a different vehicle that's on you too. Otherwise things happen and I'm glad to hear that Subaru is repairing this under warranty.
 
#33 ·
I'm not sure that it is appropriate to say that you need to find a better qualified tow vehicle...
It's definitely appropriate.

I tried and failed for nearly two years to find a suitable travel trailer to tow behind my Ascent. I attempted to wring every last pound out of the Ascent's towing capabilities. Even then, only the lightest and smallest trailers could work and you would still be straining the engine, transmission, brakes, and chassis to their design limits. This might be ok for occasional, light weekend camping but not for much else. And it isn't worth the extra wear and tear it would put on the vehicle. You'd better have an extended warranty. After going over every detail on the Ascent concerning towing, my conclusion is that while the Ascent is an excellent SUV, it was simply not designed for serious towing.

Towing is an ancillary, secondary feature of the Ascent. You can tow small utility trailers, small boats, and tiny, ultra, ultra, lightweight travel trailers. Nothing exceeding around 4500 lbs fully loaded. Even then, don't push it. Avoid big hills and mountains, no trailers over 23 feet, watch the transmission temperature like a hawk, and keep the speeds low.

This absolutely pales in comparison to vehicles actually designed for towing. After failing to find a travel trailer suitable for my needs that my Ascent could handle, I purchased a RAM 1500. It can tow a 12,800 lb trailer with a 1,300 lb tongue weight with no problems. And the 1500 is considered a lightweight tow vehicle. The RAM 2500 and 3500 can tow many thousands of pounds more. Compare that to the Ascent and you can easily see that the Ascent's towing capabilities are pathetic. Its engine, chassis, and transmission were simply not designed for towing. You can't even use a weight distribution hitch on it. A WDH is absolutely essential on any serious towing vehicle. Without one, you cannot properly distribute the tongue weight to the tow vehicle's front axle and the trailer's axle(s). This limits towing capabilities severely.

I love my Ascent, it's one of the best vehicles I've ever owned and a near-perfect SUV. But a towing vehicle it is not. If towing is vital to you and you need to tow something even moderately substantial, buy a serious towing vehicle.
 
#34 ·
The OP described the trailer as "a small teardrop trailer." It's likely this trailer is under 3,000 pounds and relatively aerodynamic. The benefits of a larger tractor are certainly numerous, but the stated load in this case should be well within the capabilities of the Ascent. In other words, it should not have been a factor in this transmission failure.

I absolutely agree that the more capacity you have above the load you're carrying, the better your experience will be.
 
#35 ·
It should not have been a factor in this transmission failure, but it was.

The Ascent was not designed for towing. If you tow even lightweight travel trailers with it, you are going to push it to its design limits. I expect to get 10 years and over 150,000 miles out of my Ascent, that's why I don't use it for towing.
 
#42 ·
Oh, absolutely. Lack of CVT fluid (or the fluid being very low) immediately comes to mind. It's also possible the CVT fluid was so "varnished"/"burnt" that it was no longer functioning as CVT fluid. Another component breaking and wedging between chain and variator cone at high enough speed to break the chain, maybe? I think there are a decent number of non-chain causes that may cause one of those chains to fail.

Apologies to any if my comment seemed too direct - I had a short posting window. I just didn't want people thinking the chain itself is prone to exploding, under any normal operational circumstance, or under any load.

It obviously catastrophically failed - and I am very very interested in "why?" - it's just not the design. People (especially WRX owners showing off) tow all sorts of things (like WRX owners and 18 wheelers) with their TR690s, and this doesn't happen.

Can continuous towing contribute to a CVT failure or some other sort of issue in a limited-duty-tow-vehicle, like @pro10is said? Absolutely, positively. So, is this related to towing? I'm not sure - there are people in this very group who tow more weight, through the mountains, in the desert.

So, what's the cause/determining factor? I don't know, and can't speculate.
 
#43 ·
I like that Subaru will replace NOT repair a bad CVT.They put in a brand new unit covered by warranty and you're good to go.Too much fiddling with certain components can make thing's worse in the long run.
I for one was never a fan of rebuilt traditional transmission back in the day and now with these CVT's still no way.
 
#44 ·
Most dealers (subaru / non subaru ; cvt / non cvt) will replace the transmission not repair it.

Personally , I doubt a 1.5" lift or a teardrop would cause any issue; we tow a 3000lb rig; before that we had a pop up with the Ascent and it was barely noticable.

I have started to be more and more concerned about the CVT when cold. I am noticing issues with mine (we are trading it in the next few weeks). The CVT transmission fluid is very temperature sensative. The chain could have been bad' something else may have been bad; either way the transmission temp light came on. Sadly the dealer does jack if they can not reproduce the error. If there was an issue with the transmission fluid temp; there are a whole host of problems that can result; yours being one of the more dramatic.

I would take a good look at the skid plate you added. If it extends past the front wheels, I would be a little worried the skid plate is acting as insulation and for a longer highway trips posing a problem. Could also be a tranny cooling issue.
 
#49 ·
For my part, I was not directly comparing an Ascent to a pickup truck. My point is that you require a vehicle specifically designed for towing if you want to do serious travel trailer towing. This could be any vehicle with an engine, transmission, chassis, and brakes designed to tow a typical travel trailer (not a super-ultra lightweight TT).
 
#57 ·
Well, for me the Ascent was a great tow vehicle.

I towed over 5,000 miles at/near/sometimes over the limit.
It would tow my Mustang + flatbed trailer (4,500lbs) just fine, even up and down the mountains.
It towed my 4,000lb camper just fine from the base of Mt Lemmon at about ~2k feet to the campground near the top ~8k feet on a hot day in 35 minutes.
When I got my Telsa 3 Performance, I towed it on my flatbed (5700lbs) to the track just fine too.

Before I had my Ascent I had a GMC2500 (14,500lb towing rating) towing a 10klb fifth wheel. Even compared to the GMC I have never felt like my Ascent was underpowered or under capable for the loads I was towing. Obviously can't tow a fifth wheel or larger travel trailer with the Ascent, but up to 5,000lbs? Always felt great.

One time braking hard downhill I had my trailer get a bit squirrely after I was cut off. But the stability control kicked in and pulled the trailer right back in line.

Wheel Tire Car Land vehicle Vehicle
Wheel Car Tire Land vehicle Vehicle
 
#58 ·
Sometimes stuff just blows up. We had an RV that was on a 2008 Sprinter chassis back when it was branded Dodge (Daimler Benz). We live in Oregon and a short time after entering Florida, the transmission had a complete stroke. About 20,000 miles on the odometer. We were towed 60 miles to the Dodge dealer in Gainesville. We were still 180 miles from our destination. The dealer rebuilt the transmission and replaced the torque converter twice. After the first rebuild, the transmission blew up 45 miles from Gainesville and had to be towed back. Spent the night in the dealers driveway. The whole deal is more like a short story and I won't retell it here. We were stranded staying with friends from Halloween until after the new year. The second rebuild only lasted until Tallahassee on our first escape trying to get home before Christmas. The dealer there, overbooked with work, told us to turn back to our friend's place and avoid Gainesville. Down in Sarasota, the dealer installed a new transmission and torque converter. It was perfect for another 80,000 miles when we sold it with no diminished value. We now have another Sprinter (2016 chassis) and is serviced by Mercedes Benz now not Dodge, thank God. We were told after the fact that the dealer should not have attempted to repair the transmission, but did so because they thought that could repair it under the warranty allowance. In short, they were chasing warranty dollars. The transmission was the same one used in vehicles with higher horsepower and torque than the Sprinter; found in Jeeps and Dodge muscle cars. Both tow truck drivers told me that they had never towed for transmission failure; usually turbo or other Diesel engine related problems. The faulty transmission and torque converter was supposed to be returned for analysis and replaced with re-manufactured parts if available. None were at that time so they installed new. The factory guy told me that he was pissed because the attempts to rebuild hid any clue to the failure. Sometime stuff blows up and it's not anyone's fault. I have towed up to the max with our Ascent up and down 6% to 8% grades with no issues, but only occasionally. I found that whenever on any kind of a grade, manually selecting 'gear' ratios puts less stress on the transmission. Like other commenters I have to agree that the Ascent is best suited for loads half the maximum. I got the factory installed hitch mainly for accessory carriers and not for dedicated towing which is better accommodated with a vehicle that can handle the load. For a boat and trailer under 2,500 lbs, the Ascent is just fine in my opinion.
 
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