This problem is on a 125k '01 Ram 318 Van. I've regularly maintained the trans but it has started to act up. At about 25mph to 30mph it sounds/feels like I'm driving over rumble strips. This only occurs when I am driving it pretty slow. The noise goes away once I give it gas causing a downshift or if I let off. At first I thought it was a torque converter shudder but at 30mph? The fluid is nice and has about 25k on it since the dealer flushed it. Any ideas or input?

 

That is the noise that started in my 98 ram a few years ago. See thread https://dodgeforum.com/m_955179/tm.htm. End result after about 3-4 years of it getting progressively worse was a (second) rebuilt transmission. I don't know if you can do anything to prevent that. I was told it was the transfer case and to just drive it until I was ready to replace it or it gave out. Turns out the transfer case was fine and it was the transmission all along.

 

Well this is a 2wd van so I'm pretty sure its not the transfer case :P I'm pretty sure its the trans but unsure of what exactly it is. Might be a solenoid sticking or the TC shuddering. I'm going to flush and fill the trans fluid and see if that helps. I'll post back!

 

Well I installed a new filter, new ATF +4, flushed out the system, and I adjusted the bands. No improvement yet. It still rumbles at the same speeds. I am hoping it takes a bit for the fluid to work in. Any other input?

 

Is it making a bearing type sound ? The 44/46 RE transmission has had problems with the plantenary gears and the large roller bearing in the overdrive unit. If you can raise the van try to isolate the sound.If the sound is traveling down the driveshaft then the problem would be in the overdrive unit.