I have a 2WD 4.7 flex fuel automatic tranny. The issue is I have had it into the dealership 4-5 times over the last two years to find out why the transmission erratically shifts and sometimes a HARD shift results in the truck slamming gears and causing the engine to shut off in traffic. This only happens when the air conditioner (or defroster in the winter) is on. Rain, sun, snow or fog, doesn't matter. Typically this happens at highway speed, 55 or higher. The dealer has made sure the tranny is up to date on all firmware, all the electrical checks out, nothing mechanical is wrong either. I have had the battery, battery cables, and alternator all checked and are within specs. I have talked with a couple other guys that have had a similar issue, they told me that a cable was replaced somewhere and all was fine. I have followed the voltage 12+ from battery to fuse block/power distribution block under the hood. I am looking for any help that I can. I've spent a ton of money chasing this issue. Dealerships, auto electrical shops, other mechanics, backyard mechanics, etc - to no satisfaction.

Thanks for any help or assistance!

 

May sounds a little bit too easy after all the efforts you made, but did you ever disconnect the battery by yourself so all data incl. shift timing is reset?

 

Yep. After taking it to a shop and paying thier fees many times, I started to take off the negative terminal and let sit for 30+ mins to zero out. That's my "easy fix" or work around right now. It works great for a week or so, then the crazy shifting starts again. Also, to add to the confusion, if I notice it shifting crazy, I will floor it hard to get it to shift to a higher RPM. After the tranny shifts down, I get off the gas and it works fine for a short trip. (Less then 30 min.)

I tell you, it is possessed by a electrical demon!

 

i wonder if it is a grounding issue?

 

ive had the same issue for years im on my 3rd transmission 2nd drive shaft and 2nd rear end and still have the same hard shifting problems and searching for gear problems and grinding and clunking when shifting into reverse problems ive always had im satisfied its an electrical issue the dodge dealer around here just says "oh thats common dodge sounds and behavior it doesnt hurt anything"

 

I'm having similar issues with my '07 Ram 1500. I took it to the dealer a week ago for tranny service and it drove fine for a week, now it shifts hard. Bringing it back on Thursday to see whats up. Appreciate any heads up advice before I take her in

 

Keason5

Sorry to hear about the ongoing issues with the hard shifting. Seeing as you are going to a Chrysler dealer on Thursday, I’d certainly be able to review this further with you.

If you want to PM me your VIN# and the name of your servicing dealer, I’ll be able to review some more information and we can work on resolving your concerns.

Look forward to hearing from you.

 

i wish dodge US would check on mine its a flawless truck i love it except the whole shifting issues and the grinding and clunk in reverse

 

I hear you razor. The amount of money the dealership has received over the last couple years to fix this issue, well its over half a new transmission. Don't want to get rid of it, but I'm also not going to keep spending money on a fix.

I spent some time and followed the wires looking for a loose connections / corrosion on them. I didn't find any. There is a small spot corrosion on one of the windings in the alternator, but it isn't touching any other windings.
It's just frustrating.