240 General: 1979 Volvo 245 swapping a BW55 for AW55 ?

[Minniethemoocher]

Hello all,

I have a 1979 volvo 245, that has developed an auto gearbox problem when hot. (locks up, and stalls the car)

It currently has a B21 engine, with a BW55 gearbox.

It may be lack of cooling, or a blocked oil cooler, and that we are looking into as well, but as it is very high mileage, and we'd like it uber reliable, I'm not happy with small fixes.

Now, eventually, I'd like to get the original box repaired/rebuilt.. but in the meantime, a good running unit fitted, will solve our woes.

I've been offered an AW70 unit, from a slightly later car, and was wondering if this fitted? (complete, with mounts, converter, linkages, prop, shift lever, ect, ect)

Any help, or input massively appreciated.

[harvey]

From the very small amount of information you've given it sounds more like a converter fault rather than a gearbox fault.

[classicswede]

It will fit but there is no connection for the speedo on that box

[Minniethemoocher]

Hmm.. not great news.

Is there an early AW70 that has a manual speedo takeoff? (they appear to have been supplied to some cars in the early 1980's) and if so, is there a cut off point to electronic?

[classicswede]

The change would be around 85 ish

[Minniethemoocher]

Thank you for all the advice.

The AW70 went in fairly easily, albeit a couple of points:-

Converter
This has to be the AW one as well that matches the box
Speedo output
as for the speedo, it's the simplest bit, as you can swap the tail housings/gear/spacers between the AW and BW
Prop shaft
The props are different, with the front section having different end flanges, so if you do the swap, you have to have the prop as well. The centre housing is the same.
Rear Mount.
This IS the biggest issue, as the AW box is longer, and so the late cars must have a slightly longer flat area to the chassis rail, and re positioned fixing holes. This means on an early car it half hangs out past the flat chassis rail area.
With a bit of jigging about, we are using the original 2 rearmost mount holes as front holes (on the mount), and are making up a packing wedge, and some new fixing holes further back.
Gear lever and Wiring
Gear lever is different. the box is longer at the front just behind the converter, so the gear lever rod has to be longer to meet the box arm.
Some wiring plugs fit ok, like the illumination, and the inhibitor, but the overdrive part of it, is totally different, and the early cars do not have the loom. The late gear lever also has the overdrive switch if needed.
The cheapest option is to buy the 'bypass' plate for the overdrive, so it'll always just go into 4th anyway.
If I keep this box, I'm making up a sub loom with the correct relay, running from the correct fuse takeoff.

I hope this may help someone else.