Transmission Lessons & Question

Sup yall,

I've been absentee for a while as oddball spent from late July to mid September in the shop trying to work out some transmission issues. Without going into the mind-bogglingly ridiculous story and life lessons I learned from handling this ordeal, I'll give a synopsis:

Ever since I got into that argument with the guardrail in the snow 3 years ago, upon deceleration, there has been a faint high-pitched winding-down noise that decreases in both pitch and volume the closer I come to a stop. After a couple years of ignoring this, oddball started making a stuttering noise when slowing down, more prevalently when under 20mph, and even more prevalently when turning. Oddball was driving fine, but it got to the point where you could tell that something was just waiting to fail, and that something could cause larger issues. So since I had the money now that I was out of college I decided to take it in. They put (effectively) a stethoscope up to the transmission while engaged on the lift, and determined that it was more than likely the diff. Long story short, 2 completely separate rebuilt transmissions and 1 practically rebuilt original transmission later and they could not solve the whining problem. The stutters were gone (replaced torque converter) but that whine was still there. Anyway, I got the car back with a very altered (in my favor) quote, and took the car as is. Unfortunately, oddball started idling so low he was shutting off while in park sometimes. Additionally, there was this screeching noise along with a heavy rumbling whenever the transmission was engaged. So I brought it back in and they did a courtesy check to find out what was going wrong. They said it seemed like I had a broken transmission mount, and that I could probably fix it myself, and that because they had reset the ECU it needed to relearn. I know objectively it seems like those 2 things should have been fixed right then and there, but it's a long long story. The point is, by the grace of God, I switched out my severely broken trans mount (easier in theory than practice) and low and behold, it solved both issues, and... the whining noise I brought it in for. With all that said, the lesson is, check your dang mounts.

Question: Even after I swapped the mount, Oddball vibrates pretty harshly right when I hit about 35-40mph under smooth acceleration (so when it's chillin at about 1500-2000rpm, usually in 4th). Once you get past 40, no problems. If you accelerate more than average, no problems. If you let off the pedal when it starts to shake, no problems. So the question is, does anyone know what that might be about and how to fix it?

-Garrett


PS If you are having similar issues with anything I mentioned, feel free to ask, I have a lot more info than I put in that story.