Hello all I have found some good info on this forum and decided to join in hoping for some help with my drivetrain issue. I have a 1992 Fullsize blazer that is makings some very bad noises.

WHen I accelerate i start to get a hop and loud clang noises that get faster and turns into a vibration with speed. If I let off the gas the noise stops for th emost part and no more vibration. If i shift into neutral there is no noise or vibration so I am not thinking it is a wheel bearing or bearing in general. My thought is bad u joont but I can't seem to feel any play in them or on the driveshaft. So is it likely that it is my rear differential as the sound seems to be completely in the rear end.

on a side note it seems like when I shift the tranny into gear i loose engine oil pressure. If i shift to neutral the pressure seems to jump back into the green.

any and all help is super appreciated as I am your local starving artist with a big SUV.

 

did you check the u-joints by removing the shaft? do the u-joints seem notchy when moved?when shaft is removed check diff. yoke for any roughness or play.

 

I don't have any tools where the truck rests to remove the driveshaft. When I move the driveshaft in neutral it seems like there is more movement on the transfercase side but I still dont sense slop or roughness on the u joint. I cannot move the driveshaft much in either direction should I be able to spin it freely or should I feel resistance?

thanks for the response!