whining th400 after filter change

[1984dually]

Transmission was bought as a reman unit a couple of years ago and has been trouble free. Decided to service it with a new filter and now it whines. Pulled the pan and didn't find any problems but changed the tube orings and another filter. Whined for a few seconds and quit whining. thought it was fixed until starting it up the next day and whine is back. Pan was clean. Any ideas?? Never made a sound until filter change.

 

[DoubleDingo]

You're going to have to drop the pan again. Find a transmission shop that sells the brass filter. You probably got one stuffed with dacron. I ran through this same thing last year. Did a filter swap, the one I pulled out was the brass type. Installed the new one that had dacron. It whined when started and when hitting higher revs when manually shifting. I even put a second dacron filter in it thinking the other had somehow plugged up after a few weeks of driving, but it still whined with the second filter swap. Found a local shop, bought the correct filter, installed it, no more whine.

 

[Matt69olds]

What he said. Only other idea is cut o-ring on the pickup tube.

 

[Craig 85]

I had an issue with my truck last year. Had the trans rebuilt, then my engine went out and sat in a shop for a while. I got the truck back as the weather started to change and get colder. I found when temps were below 50 degrees it would whine until a little heat got in the transmission. Maybe a 1/4 to 1/2 mile. The sound would be gone until it was cold started again.

Turned out the pump in the transmission was bad. Thankfully still under warranty. They replaced the pump and runs perfect now.

 

[1984dually]

Going to change to a screen type filter from a 540 Allison trans. Think the original was one. Changed about a 100 400 filters and this is a first. Thanks for the help