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Discussion Starter · #1 ·
Hi all,

Just had a post a week or so ago where I got some detonation issues seemingly resolved, only to have a totally separate issue pop up a week (1k miles) later. I've always been fearful of the CVT failing, just because it's worth almost as much as the car, and now it appears something trans-related is going on - although I don't think it is the CVT itself.

Just yesterday, once warm (for the first few minutes upon cold start, it seems to act fine.), the car will jerk very hard upon accelerating from a stop (before 1500 rpms). At that point, it will drop the rpms to about 1k, then shortly after bump back up to about where it was. I'm thinking it's one of 2things: torque converter (doesn't have the normal symptom of wanting to stall when stopping quickly), or the torque converter lockup solenoid. I know the lockup solenoid is the easiest to test by dropping the valve body and testing the solenoid, so that's probably the way to go before dropping $600 on a torque converter and pulling the engine. The car drives totally fine once moving (and even in reverse), and I haven't tried the "manual mode" yet as I've seen some other people say makes a difference. It has no abnormal qualities in reverse.

Really just looking for any additional feedback - particularly from those that have had this exact issue and had it resolved, as well as other troubleshooting/diagnostic techniques. Not interested in taking it to the dealership for repair because of the cost, and being fully capable of replacing parts. And at that point, it makes no sense to have them diagnose it because then there's no standing behind the diagnosis when I do the repair work myself.

For reference, the car has 175k miles and has the original trans/torque converter. No codes present.

Thanks.
 

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2021 OB Touring, 2011 OB Premium
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From what you are describing, I would suspect the valve body. I don't believe that the lockup valve/solenoid are involved, or you would be stuck in a higher "gear" when the car started moving. Also, how long has it been since the trans fluid was changed? Best of luck. . . .
 
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Discussion Starter · #3 ·
I changed the fluid when I bought it at 140k (still looked clean, not that clean indicates it still has the correct properties) and again at 160k. To be fair, it does seem like it is in a higher "gear" immediately upon the jerking that I have been taking as TC lockup but isn't noticeable once moving. Also, it doesn't have any symptoms when cold, which is when the TC doesn't lock right away in order to warm up quicker. The valve body is definitely the easier job, I'd just hate to replace that and then have to go pull the engine anyway and buy the TC as well to put in a 175k mile trans. On the other hand, I wonder what the odds are of SOA providing a reduced cost whole CVT...oh well, I expected some problems when I got a higher mileage car last year when it was what was available when mine got totaled.

I'll continue to update as I diagnose/repair.
 

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01 VDC, 05 R Sedan, 06 BAJA EJ257
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I'm going with valve body. I've had this before when you start from a stop and it would kick and its the valve body applying pressure to engage the pullies.

If you have a way to look at trans data, you would look at torque converter rpm/slip, input shaft speed and output shaft speed. If you put the car in drive holding it still and the input speed is not 0 when the car is stationary, it's not the torque converter, it's the VB.
 

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Discussion Starter · #5 ·
Yeah it's probably about time I invest in a good scanner since I do all my own work on vehicles. Another note: I wanted to see if there was a way to change the symptoms. I know sometimes when you put a car in manual mode it will have different settings for the trans - in fact, it does not behave the same if I put it in M and use the paddle shifters to get up to speed. There is no hard jerk in this case. I used it as a temp measure yesterday just to go to work until I can work on it this weekend. I figured that might be a useful piece of diagnostic info, but maybe not.

Thanks
 

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1997 Outback, 2016 Forester, 2022 Outback
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This probably won't help, but I just completed a flush of the CVT in my '16 Forester at 93K miles. First time AFAIK. This car has the "continuous" CVT, if it matters; a TR-580.
The car was sometimes a little abrupt coming off of the line, and the fresh fluid seems to have alleviated that. No other noticeable changes, but the fluid is Green now, in any event :)
 

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Discussion Starter · #7 ·
So since I got the car at 140k, I've changed it twice (drain and fill) in hopes of not developing issues. The stuff that came out didn't look too dirty either, but I was planning on keeping up with that every 30k.
 

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Discussion Starter · #8 ·
Quick update - not fixed yet, but up on stands in the garage ready to go with new parts. I got kinda screwed buying a "new, open box" valve body on FB marketplace that turned out to be used and have a bad solenoid. That's beside the point, and I'm covered there cost wise with purchase protection if I can't reach an agreement because the seller did admit it was used briefly for testing when questioned.

Anyway, I tested my car and the lockup duty solenoid was out of spec (8 ohms, vs the 10-13.5 spec). I should have it completed tomorrow one way or another, likely just swapping the single bad solenoid given my parts situation (as well as replacing the trans fluid filter). I'll update Sunday with whether or not the results are as expected.
 

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Discussion Starter · #9 ·
Its fixed. I swapped out the solenoid, put in a new strainer("filter"), and refilled with CVT fluid according to the procedure, and all is well. I was hoping I wouldn't need a new car in this market. Thanks to everyone who contributed!
 
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