So some of you may remember, I had a torque converter slipping several months ago causing heat to build up and triggering the computer to disengage overdrive. The truck ran and drove fine despite this, but since the hunting property is about 100 miles away I wanted OD for obvious gas mileage reason.

So I had a Jasper certified shop install a Jasper transmission. My trans is still under warranty (3yr/100,000 miles), and has driven beautifully up until this weekend.

So this weekend I did some very light trailer towing (pulled an empty utility trailer up to the hunting property). Once up there I had to use 4x4 to get through some snow and ice. Very light usage I might add just to keep from getting stuck.

Now when I drive, the truck on upshifts drives beautifully, going through the gears nicely until I am at cruise speed. Then, if the truck is accelerated to the point of needing a downshift, I get this weird vibration and noise from the transmission/transfer case area, until the downshift is complete then it accelerates fine and then upshifts normally again.

On the way back, with the trailer now carrying an ATV, I found that it wasn't nearly as bad when downshifting out of 3rd into 2nd as it was downshifting from OD into 3rd, so I just turned OD off. However, I still experienced it in the 3rd to 2nd downshifts, just not as severe.

Weird thing was that the problem almost completely disappeared near the end of my trip. The last 15-20 miles it downshifted without the vibe and noise, and I even popped OD back on just to be sure. I think it did it one time in the last 20 miles or so.

Obviously I am going to try to get this into my trans guy again, but any thoughts anyone?

 

If it was a GM product, I would say TCC shudder..... but, not aware that dodge had an issue with that.....

 

Could this cause it? So the other day I went to take my buddies trailer back to him. I pulled forward in the driveway, then waited to hear if he was home. When I got back in the truck, it wouldn't shift into gear. It felt like the shifter was disconnected. Crawled under and sure enough the linkage had come undone. Got it hooked back up. Haven't test drove because I don't have a pin to keep the linkage connected. (Anyone know the best place to pick one up?)

Could that have caused the vibration during downshifts?

 

Probably not.... but, won't hurt to have a look at the rest of the linkage, and replace any worn bushings and such. It's probably just a cotter pin that holds in it, or a spring clip..... Your local parts store will have a selection on the shelf.

 

So turns out you might be right HeyYou. Though more of a problem on diesel Rams, apparently a bad alternator diode can cause TCC shudder in just about any electronic controlled transmission. Even read about it on a Ford Taurus forum.

So I'm going to pull my alternator fuse and see if it goes away. If so I'll buy a new alternator.

 

Let us know how it turns out.

 

My trans guy had me test the electrical theory by driving the truck. When the lock up happens to lightly touch the brake pedal with my left foot just enough to make the lights come on. As soon as I do that the vibration goes away and the trans downshifts without a problem.

So I am going to try removing the alternator fuse next.

 

So, I had something like this happen on my Ram. Seems to disappear when I boop the overdrive switch on the shifter stalk to "O/D Off".

Only lasts for a couple of seconds at high speed and disappears with O/D off.

Wish this guy had given us an update.