My new first time Volvo is a 90 wagon. The differential cover was leaking and I got what i thought was a good deal on an aluminum 740 cover. Had it replaced and now no speedometer.
The question is can a 740 cover (of unknown origin) work on a non-ABS 240 with manual trans? Or do I need to spring for a new steel one?

After the fact, I see the recommended clearance of the sensor is rather tight and the rusty cover had a paper type gasket and was replaced with a thick felt like one which would throw the clearance way out. Also, this may be wishful thinking but the odometer may flipped to the next tenth since it was changed though speedometer was was not noticed to be working at all.

 

the differential innards are the same. the ABS cars have more notches on the 'tone ring' but the sensors are otherwise the same.

 

I have the diff cover that uses 4, 7/16 inch bolts to hold the rear spring on. Do the front two bolt holes dead end or do they extend through the top of the case? I think used the 78 and 79.