I have a 87 S10 Blazer, with a 700R4 transmission. Yesterday I was driving on the interstate doing about 65-70, a normal speed i go while on said interstate. It was driving fine, but once I got off the interstate I started to hear a somewhat loud grinding noise. I let it sit for about an hour and half. Then I went to drive it again and no noise, but one the truck warmed up, it almost seemed as though the transmission "disengaged" it's self. I would put down the accelerator and the RPMs would go up, but the truck wouldn't move, it would just coast from previous speed before the "disengagement". I checked my tranny fluid and it was a little low, and added some to see if that was the problem, which didnt really work because it would still randomly disengage. If I parked the truck off the side of the road and let it sit for a minute or 2 and start it back up, the transmission would engage again and run for a little, then it would disengage again. Tomorrow (4/14) I will be draining the transmission fluid and flushing it out, then replacing with new fluid, checking for metal shards in the filter. A buddy of mine helps me a lot with my truck and he said it could either be the transmission, the clutch, or the torque converter.

Any ideas?

 

sounds like the trans is failing, i doubt its the Torque converter unless it has come undone somehow from the engine, but then it would never pull. Could be alot of things, failing trans pump, valve body, clutches damages from low fluid and slipping...

 

I did a fluid and filter change and checked the fluid for shards and it was fine. i twas very dark, but it was clean from metal shards. The fluid and filter change worked perfectly. Truck runs just about perfect now. I put Type-F in instead of Dexron III because I heard that Type-F causes for smoother shifts and lasts longer. I do appreciate the advice you gave. Could help for future events or for other cases.