Help With My 1999 Suburban

oakr8rs

I have a 1999 Chevy Suburban with a 5.7L 350 Vortec engine, 2-wheel drive. I had a rebuilt 4L60E transmission put on it and at first it started a little bit rough but pretty normal. It then started making a little bit of a grinding noise, then it got a little bit worse but it would still start and ran fine. One morning, it started but what I think was a metal grinding noise was really bad. I went to come home at the end of the day, and when I went to start it, the grinding was still really bad. Instead of turning over, the grinding sound went away and I heard a spinning sound. I thought it was the distributor shaft spinning but I’m hard of hearing and I’m not very good at localizing sounds so that was just my best guess but I’m positive I heard a spinning sound start as soon as the grinding stopped. (All these sounds are occurring while trying to start the truck by the way.) When I looked under the hood and had my wife try to start it, it sounded like the distributor shaft was just spinning free. I had it towed and pulled the distributor shaft, which looked normal, and reinstalled it with correct timing. The spinning sound was gone but grinding sound was back when I tried to start it again. This engine only has about 30,000 miles on it. Does anyone have any ideas about what type of problem I might be looking at? I would very much appreciate any help. Thank you.

Mr_Shiftright

Hard to hear a noise from this distance...given your info that a) the noise occurs when you try to crank it, and b) that you recently installed a transmission, I'm wondering if you have a flywheel or flexplate issue. Pulling the starter motor might reveal something when you peek inside there--or removing the transmission inspection plate if this model has one.