So my rear axle craps out because the oil shop owner pushed the rear check plug inside the rear axle and left it there... without telling me of course...and yes, you guessed it, it got caught in the gears as I was going 70mph... errr 65mph and the rear axle froze up and I skidded to a stop... he denied it of course... in court under oath...

but at any rate,

I had to put in a new(used) rear axle rather than replace the differential gears... but my car is an 88 manual with 3.31 gears and the only one I could find in a reasonable amount of time is out of a 91 automatic with 3.73 gears. No problems so far and it has been running fine for about 6000 miles.... the overal engine RPM is only about 500 RPM higher than before... slightly lower gas mileage.

But here's the problem... The speedo sensor on the new rear axle doesn't work with the old.... it gives me speeds waay higher than before... like it says I'm doing 120mph instead of 30mph...

So I put the original rear axle cover on but I see it is visible different than the one from the 91... the 91 has a thick aluminum rear cover (about 3/8 inch thick) whereas the original is pressed steel and only 1/8 inch thick. No problems so far, but when I go to put it on, the speedo sensor rubs against the differential. Unfortunately, I only learned this after I had driven it close to 60 miles... nice.

At any rate, I really want to use my speedometer again. Does anyone out there know which year volvos had the thick aluminum rear axle covers, AND does anyone know how to tell which one will work with my car??

Thanks.

Mike