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Bad shifting after transmission fluid flush

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

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FireFox31
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Re: Bad shifting after transmission fluid flush

Post by FireFox31 »

Thanks for sharing that you reset the adaprion and it worked well. For my terrible G70 transmission, I will plan to reset them immediately after the flush. I hope that will help the torque converter which may be constantly locking and unlocking while coasting.
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V50M66
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Post by V50M66 »

FireFox31 wrote: 25 Aug 2023, 22:12 Thanks for sharing that you reset the adaprion and it worked well. For my terrible G70 transmission, I will plan to reset them immediately after the flush. I hope that will help the torque converter which may be constantly locking and unlocking while coasting.
I should clarify that it worked well after internal repairs on my ‘04 XC. Not exactly apples to apples, but it’s pretty similar from a software standpoint so it should still be ok.

Mine does that too (unlocking off the gas, then re-locking on the gas), but otherwise seems perfectly fine. Not sure if that’s just how these old 4 speeds are.
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Post by abscate »

I’ve observed this on my AT 1999s with DENSO, the torque converter doesn’t unlock on coast, but the minute you reapply torque, it unlocks briefly , then locks again, as shown by the tach

I think this is normal, but my Venn diagram overlap with normal is rather small.
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Doferr
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Post by Doferr »

I’m experiencing a similar issue. After three drain and fill cycles, my transmission has a rough shift between the second and third gears. However, I’ve noticed that this problem only occurs when the car hasn’t warmed up yet. Once the car reaches its normal operating temperature, the shifting seems to return to normal. Last night, I reset the fluid counter, which may have worsened the problem. I’m considering resetting the adaptations, but based on my research, this is only recommended for transmissions that have been repaired. What are the risks of resetting adaptations in my situation? Could it lead to damage?

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