I would like to say a big thanks (David87) to spending time and explain in very good details ..god blees

 

Old thread I know, but I wanted to add my affirmation that replacing the shift solenoids can fix your problems. I have a 2006 S80 2.5t that was slipping out of gear and slamming back into gear when slowing down to make a turn, or coming off a speed bump, roundabouts, etc. It also had hard downshifts (but my mounts were all trashed too, so coulda been that).

I spent 2 days taking my time, but I replaced the linear solenoids (Rostra) and changed the motor/trans mounts about 18mo ago. It was not easy, lots of hard to reach bolts, and I was not using power tools. Reinstalling the solenoid cover with wet silicone was tricky, but I got it on the first attempt and no leaks yet. Put the car on ramps, dropped (did not remove) the subframe, and used a couple jacks to raise the engine/lower the subframe.

ATF had only had 1 or maybe 2 drain & fills in its life of 176k miles. Came out coffee black. Did 2 drain/fills with Toyota IV ATF and added a magnafine filter. Never did adaptation or reset, just drove it to relearn. It was weird at first, with newly hard upshifts, R-->D, D-->R , but after maybe a month, it was like new again. Only noticed the original symptom maybe twice since I did the job, and that was early on. It's been about 10k miles since then, and I can say the trans is fixed. If you have these symptoms, try it!!