I had posted something a few weeks ago about this. I have a vibration at 45 MPH in overdrive (Auto Tranny) with the RPMs about 1300 to 1500. I do feel it at other speeds in overdrive but it is most noticeable at 45MPH. I had the computer flashed and no change. I took the front driveshaft off and drove around and no change. I don’t feel it after I turn the O/D off. The service guy at the dealer said well then turn the overdrive off (f--- dumb a--). Something is not right I don’t think it is a tire b/c it stops as soon as the eng RPMs change. Anyone have a similar problem?

 

Mine has started doing that a while back and at about 55 mph. You are right about the rpm change, if I speed up or slow down it stops. I didn't think about turning off the OD, I'll try that on my way home from work and post later.

 

Nothing can be done about it. We have shitty trans. in our jk's . The torque conv. locks up in that rpm range and we get the vibration . Turning O D off only helps at certain speeds becouse it will kick the rpm's to about 2000. The stealership told me all the jeeps on there lot had the same vibration when they test drove them after I brought mine in to be looked at.

 

I get that, and if I turn the overdrive off it goes away. Since the driveshafts are spinning the same speed at 45 regardless of the gears, my guess is that it is the engine getting bogged down and causing the vibration.

 

I have had a few cars with a stick (had to get an auto, wife, oh wait that is another subject). It feels just like having the car in to high a gear for the speed you are driving at. Like you are in 4th and need to down shift to 3rd. That is the best way I can describe it. D/C should be able to fix this.

 

https://www.jk-forum.com/forums/show...400+rpm&page=2


Here is a bunch of posts on it..

 

This has been discussed a lot. Same issue here. Its the TC locking up and you are feeling the low rumble of the engine which does not go away until it unlocks. I have had my TC replaced and software flashed, each works for a few hundred miles until the computer decides it is time to let the TC lock again.

There is no fix, however it should be something as simple as a software update. Sadly Chrysler does not give a crap and has not released such an update.

 

This is a perfect explaination of how it feels! Too bad we have to live with it!

 

Well, maybe we will get a fix when the bail-out money starts to flow

 

I am sorry to hear that we all have this problem and that there is no real “fix”. It is good to know that it is not something serious. With the treads about transfer cases cracking from vibrations in the drive line, this was a concern that this may be the start of something more than the T/C acting up. That’s why I pulled my front driveshaft.