My Dad has a 2000 3500 Dually with Cummins and Overdrive tranny. I'm researching this for him. The problem: The truck shifts erratically in Drive or Overdrive only between 1400 and 1600 RPMs, usually when going up a slight grade or hill, but it will do it on the level, too. In 1st or 2nd gear, there's no problem. You can watch the tach and see the needle jump back and forth, and you can feel the "lunge" or "surge" when it happens. It used to be very intermittent, sometimes not occuring for a year, but it's more frequent now. I read a post that said maybe the injector pump? Could it be electrical? Any ideas are appreciated. Thanks.

 

I just started to have the same problem. Everything is ok until I reach 40mph or above and hold constant throttle. Tranny feels like it shifts erratically in and out of overdrive. Sometimes it feels like a "lock-up" converter going in and out. Changing rpm by only 300-400 or so. If I accelerate it goes away. It only happens at constant throttle or a slight hill.

98 Dodge 2500 automatic (obviously)

Any help would be appreciated...

 

Check and clean ALL your ground connections. Battery, engine, transmission, and anything else you can find. It's a somewhat common problem during those years.

 

+1 on the grounds

I replied to this before but it got dumped. I too have had this problem and after throughly cleaning the grounds and applying some d-electric grease the trans shifts just fine.

 

Had this problem for a couple years now.On charging it used to charge hi and low voltage it stopped the hi part .Changed alt same thing It' a 2500 24 valve 1998.

 

+2 on the grounds. TC lockup problem will seem like revs going up and down just a few hundred RPM. 9 of 10 times we've seen this problem, cleaning battery grounds and securing so they're not in close contact witht he alternator takes care of the problem.

 

having the same problem for the last week.just had trans rebuilt but didnt start doing it immediatly,50 to 60 mph cruising in and out of lockup like crazy,give it some throttle and it clears right up.towed a mud truck 130 miles to dennis andersons yesterday and it had me very concerned about hurting my new tranny...ill be going through all connections today for sure!Was a real PITA trying to follow a friend closely home that had no trailer lights at 1:30 am cruising along

 

Zip tied alt ground wire away from alt(was laying on it),wrapped alum foil around it and taped up(as seen in another post),and tightened terminal connection that that wire went to(seemed just a tad loose),drove 60 miles......not sure which method fixed it but I sure am a happier man now!.....PROBLEM SOLVED!

 

On you pass side batt you will see a ground wire going down to the batt tray.It plugs into a conection that leads to your alt.Unplug and clean or just unplug and plug it back in a few times.And no more shifting out of overdrive