I'm pretty sure it's the tranny (I checked past posts), but why not post to be sure.

It's a 1990 240DL wagon with almost 300K miles on it. The engine is a 1993 240DL with about 200K miles.

The tranny's the original. 300K miles.

My wife uses the car as a work vehicle. It's perfect for urban gardening. She'd been driving the car around Manhattan between two jobs and then back home (Brooklyn) with no incident.

She stopped at Lowe's. At first it didn't start (a problem that I'd "solved" with a new alternator and, eventually, a new battery in the past). My wife unhooked the radio plate and unplugged her phone charger (as this had been a problem in the past) and the car started up.

But once she started driving out of the parking lot, the car wouldn't get past first gear. It would make this roaring/racing sound. Fortunately she was close to home, so she put on the blinkers and drove nice and slow.

What's interesting is that we had this exact thing happen last year at this time. I was about to drive my daughter to look at a college the next day, so I borrowed my friend's car. My wife was able to use the 240 the next day. We've not had a similar problem until today.

I just now went out and checked. No tranny leak. The fluid is brownish. Smells like shoe polish. My neighbor, who likes working on Volvos, suggested I change the fluid this weekend.

Any thoughts? My brother in law mentioned the gas filter as a possible.