Hi Scotty, I have a 2000 4Runner with transmission chirp/squeals only while coasting. What could or be? I checked the front and rear drive shaft u joints. No difference. I replaced all suspension components and wheel bearings myself. The AISIN 4 speed auto shifts pretty normal for 301,000 miles. I’ve asked mechanics that rebuild transmissions and they are stumped because it is a rotational noise for sure. But there aren’t components “at least according to mechanics” in the trans that can cause that sound. I know quite a lot about these transmissions. Believe me I would rebuild it myself if I knew I could get quality parts for it. 60k miles ago I rebuilt the engine completely (it had a wrist pin knock so I replaced all bearing sleeves and piston rings) and was hoping to tackle the issue then. But I couldn’t even diagnose the sound other than finding where it’s coming from. I was hoping you might have some insight on this. Maybe you’ve heard of this before? On the various Toyota 4Runner forums online many people that have described exactly the same issue also suspect the transmission. Possibly the torque converter or its bearing. They haven’t solved the issue either. I’ve driven the vehicle like this for 6 years. The sound disappears in the summer but sometimes comes back at random intervals. In winter it’s constant or sometimes goes away magically. It drives and shifts just fine to this day. Part of me wonders if the paper or cork material on the belt eroded away. I never found evidence of this. The AT fluid is clear and I did a proper flush on it but still the same noise. Who knows maybe the best solution is to find a used transmission with low mileage. Only trouble is it’s a gamble. I’d have to disassemble the transmission and inspect everything to know for sure, even if I could buy it not sight unseen. Optionally I could get a standard and a computer to match. Luckily these 3rd gen 4Runners don’t need programming or vin matching.