Question Haveing a noise from time to time. No blinking lights from the 4x4 swithes. But if i engage 4hi it goes away. I stop place auto in neutal go to 2hi. I listen for the shift and back up about 30 feet or so to make sure. It has happened twice this winter. I have been told it could be the front alxe is to full and with the cold temps it is turning the the front drive shaft. I run nothing but Amsoil in everything I own. It shift in to Low range and out with no problems. I have own two S-10s 95 S-10 pickup and now the 2000 Blazer. I have read all that I can find out this noise and have found nothing that pin points what is causing it. Have 79 K on the blazer. 80% Hwy 20% country road driveing. HELP !
AnswerHello Kevin,
Even if the viscosity of the oil turns the differential and driveshaft, it shouldn't hurt anything. It is just coasting along, and lubricated.
Actually, my thought would be that the driveshaft is NOT turning, and since the actuator that connects the right axle to the inside shaft, is not engaged, if the driveshaft doesn't turn, and the ring gear doesn't turn, the spider gears in the front differential would be counter-rotating(What a differential does), and maybe that's where the noise is, and why it quits when you engage 4X4.
I haven't torn one of those diffs apart, so am not positive about their construction.
I have heard some people say the left axle was always connected to the differential carrier, but if that were the case, the front driveshaft would need to turn all the time, since it meshes with the ring gear.
I really don't buy that, but haven't been in there.
Van
