While the AW series (as others have already stated, a very durable, reliable unit) was used from 83-93, without major changes, an 85 car MUST have one from an 83, 84 or 85, if you want to have a speedometer. From the 86 model up, 240s have an electronic speedometer, driven by a sensor on the rear axle. The transmission from 86 and up cars will bolt right in to an 85, and work correctly, but there is nowhere to connect the speedometer cable, so it turns out the guy at the transmission shop wasn't really too far off base.

If looking for a used transmission, the only weak point to watch out for is that the tailshaft housing is prone to wear, resulting in fluid leakage around the output shaft. This is repairable, but would add to the cost of the job. The overdrive solenoid can also fail, and new ones are quite expensive, so be sure to save the one from your old transmission.

re: "...The mechanic tells us that they only made the trans for one year...."

That's crap! The transmission in your '85 non-turbo is an AW70 (if it's a turbo engine, then it's an AW71, a slightly beefed up version of the 70) -- it's the same through 1993 for all 240s from about ~'82-on.
Anyone who knows anything about Volvos would know that, so there are only two reasons why he would tell you that:
1) He doesn't know how to work on or replace your transmission, or
2) He wants to compel you to agree to let him rebuild it (at a higher price) than swap it.
Either way, you ought to look elsewhere for your repair.

There have been other transmissions: prior to '82 (or '83), there was the 3-speed (non-overdrive) BW55, for example, but that's the only exception for 240s.

Also, certain other cars (700/900 for example) had a BW70/71 (it was also an overdrive transmission similar to yours, but it had no button on the side of the shift -- instead it had a quadrant, PRND321, instead of PRND21 like yours), but stay away from it (it self-destructs too easily if you rev it in neutral, as in an idle emissions test).
Also, some later 700/900 cars had a AW70/71-L, the -L designating a lockup torque converter, a good choice for your swap, as it will give you better fuel economy!
But these variants were never in any 240.

Good luck.

Read the facts in the answers you already have, and go find a new mechanic.

That tranny was used many many years, in the 240s, 700s and 940s. Chances are you can get one that has the lock-up torque convertor. Look in later modela 240, and 740/940 models.

The AW-70 you have is tough, but the mixing with engine coolant is a killer. I think the later AW-71 and AW-71/L will work.

Good Luck,

Bob

;>)

That tranny was used in many years. They are also bullet proof and rarely fail. So reliable that they are cheap and plentifull from the wreckers. A mechanic that says it was only used for a year may also be dignosing wrong. They just love to replace transmissions.

What are the symptoms?
--
David Hunter