I did what you suggested. I drove it and listened for the noise in reverse, but didn’t hear it. I then shifted thru the gears manually and didn’t hear it in 1st, but immediately heard it in 2nd and 3rd, then it went away in 4th. It may be a gear problem. I also noticed it started thumping during 2nd gear and continued in 3rd too. I’m going to remove a quart of the fluid and add in some Lucas Stop Slip and see if that helps.Listen for the noise in Reverse and Manual Low/1st
You have gear reduction ONLY in Reverse, 1st and 2nd ---- and you have gear multiplication in 4th which is Overdrive.I did what you suggested. I drove it and listened for the noise in reverse, but didn’t hear it. I then shifted thru the gears manually and didn’t hear it in 1st, but immediately heard it in 2nd and 3rd, then it went away in 4th. It may be a gear problem. I also noticed it started thumping during 2nd gear and continued in 3rd too. I’m going to remove a quart of the fluid and add in some Lucas Stop Slip and see if that helps.