How do you replace the differential on a 1988 Chevy Astro van?

Answer 1

Jack up rear end and place vehicle on stands. You want to make sure the vehicle can't fall. Remove wheels. Go ahead and remove brake drums. Remove rear cover and drain fluid. Remove rear u-joint from differential yoke. Remove pinion nut. Pull yoke off pinion. On the differential there is a bolt which retains the spider gear pin. Remove that bolt and tap the carrier lightly with a soft-faced hammer so the pin will drop out a little. Grab the pin and remove it. Take some liquid paper and put a mark on each gear so they can go back in proper location, unless you are also replacing them. From this point on, don't turn the axles any more than necessary, as the spider gears will fall out.If that happens, they MUST go back in the proper location or there will be noise from the rear end. Push in on the axles slightly. You will see a circlip on the end in the spider gears. Remove the clip from each axle and slide axle out. Some vehicles will require a slide hammer to do this, some will not. Remove carrier bearing bolts, grasp carrier assembly carefully and roll it out of housing. Remove pinion, making sure you remove all shims while you're at it. Don't lose any shims. It is a common belief that all you have to do is count the shims, and put the same amount back in. This only works if you are reassembing using the same parts, which defeats the purpose.... When you get the replacement parts, spend the extra money for the shim kit, or if you're replacing bearings, buy the installation kit (about $100). It includes seals, pinion nut, crush sleeve, bearings, shims, and cover gasket. At this point, clean out the axle housing with kerosene or a suitable solvent to be sure you have any metal fragments out of the unit. Now you're ready to do the set-up, which is where my mechanic took over. The set-up must be done precisely, or in about a thousand miles, you won't be able to think for the whining noise from the rear end. Best wishes on this job, as it is a bugger the first couple times.