The (I think is a) A604/41TE auto trans in our winter beater '91 Grand Caravan SE howls like a dry bearing when put into reverse. No howling or issues in D, 2, 1, or N or P. The short history is the van sat since around 2017 because of a bad fuel pump and hasn't run since around that time. I decided to replace the fuel pump and the entire brake system and fired it up to take it for a test drive. Start it and have to back up but decide to move the shift lever through the gears, go to low and goes in smoothly. Let it sit in low for a minute or two and then the same into 2nd and drive always letting sit in those positions for a minute or two also. Then I put it in reverse and it kind of lurches after a slight delay so I leave sit in reverse for a few moments, seems okay and I start to back up and get about 10 feet in reverse and then it starts to howl really loud, and I stop and put it into park, then into drive and pull forward with no noise. Let it sit in park and open the hood to check the trans fluid and it's just on the tip of the trans dip stick. Grab the trans fluid and funnel and fill it to the level for hot but the trans fluid is just warm. Get in and go through the gears again and still howling in reverse only like a dry bearing or like your dragging a steel bumper down a concrete road, louder than $#!*. Check the fluid again and it's showing good and it doesn't look contaminated or dirty. Howls only in reverse and it does move in reverse but does not go into reverse smoothly. Gave up on the idea of the test drive but did think that maybe oil/fluid might get to the place that sounds needs it but didn't want to take the risk of damaging the trans or getting stranded down the road. Have some ideas from watching a 7 part video on a rebuild repair but I know there are some great transmission guys here. (I was going to say: some great "trans" guys here, but that would have moved this to the unmoderated forum ) Thanks in advance.

Mike

Sounds like regulator valve buzz. Might try and hold the cooler line while it does this - if it vibrates that is a pretty sure sign of the TV buzz.

Update us after that trial. Stationary, in reverse, nothing in the trans is turning except the pump rotors. Same as in drive.

Thanks Transman That wasn't if but I never would have found it this soon without your reply. I had my son put it into reverse while I held onto the transmission cooler line(s) and it turns out I must have a bad or broken motor mount, When you put it into reverse the engine would torque up towards the rear and very close to the firewall where I had run a new brake line I had made. It was about a 1/2 inch from the serpentine belt steel pulley and actually touched the brake line only when it would torque up in reverse. Bent it to the passenger's side and flipped a firewall clamp the other direction and no more contact or noise. Now I have to find what is most likely a bad motor mount. But all is good and drove it up and down the road out here in the country. Thanks again for your help!

Embarrassed Mike

Glad it was something simple.