850 GLT Automatic Transmission shifting very hard

Is the arrow light flashing? If not, does it light up when you shift into 3 or L or use winter mode? It sound like there's some transmission problem (electrical or mechanical) that the transmission computer is compensating for by using an emergency program. One of the "features" of the emergency programs is shifting gets harder, as the transmission is always shifted like it is at full throttle. Unfortunately you need a Volvo Scan Tool or other high end scan tool to read any codes related to this. If this is not available to you, I'd give this car a pass, as fixing it may require as much as a new transmission. (It may be much simpler (cheaper), but then you'd think they'd fix it before selling it.)

Mine was doing a hard downshift when braking and after being warmed up.

It was diagnosed as needing to be replaced. I guess Volvo only sells the PNP switch (might be your problem) and a couple of solenoids. I was quoted $1400 installed on a 95 w/ 76K on it.

My 94, in sport mode, shifts very quickly, and has done so since the beginning. I consider this an advantage for two reasons:

1. Less energy is wasted in slipping the clutches for the sake of smoothness. The energy in the engine/fywheel goes to the wheels, not into heating the transmission fluid.
2. Less wear, for the same reason. The slower it engages the next gear, the more clutch pack wear there is. After 200K miles, I haven't had any tranmismission troubles at all.

After 10 years in this car, current Volvo auto transmissions feel extremely sluggish when shifting.

To reply, please remove one letter from each side of "@" Spammers are VERMIN. Please kill them all.

If the car is really nice otherwise, I'd consider taking it to a mechanic for inspection, and then maybe paying for a trans flush and see how it shifts afterwards. It may just need new fluid (hopefully). If it is still rough, then the mechanic may have an idea, but it could be a deal breaker if the trans is going bad.

Jeff