02 Volvo V70, X/C model. The typical transmission problems of flaring and missing shifts and such. Have done the normal things, fluid flush, B4 solenoid cover, adaptive mode training, etc. No dice, transmission is still darn balky and weird. Accept that it just behaves this way, and that some day I'm going to either have to replace it or have it revalved, which actually means I'll just replace the car.
While doing other things, I decided to replace the old oem rubber turbo lines with the spiffy IDP silicone lines, because it's supposed to make the turbo behave better. The line kit was cheap, and I've had various oem Volvo vacuum lines decompose before.
It works. Took a little while as the car is highly adaptive. Nothing special as far as top end boost, but it comes on more quickly and smoothly just off of idle. Takes less throttle around town too.
And here's the transmission surprise. It no longer misses shifts. It no longer gets lost between shifts (especially when you start to apply throttle through a sharp turn you just braked for). It no longer slams into a gear once it decides what it's going to do. It just shifts.
My theory is that previously, with the leaky turbo control lines, the engine was operating "off the map" as it were, screwing up the control of the transmission. Had the wife drive it, she was thrilled! It now drove like a sane car.
It's been several days, and several hundreds of miles, and all is still well with the transmission.
