I have a 2000 quad cab 4x4 diesel with auto transmission. When it hit 60,000 miles I started having this problem. At about 1300 rpms it jumps in and out of the next higher gear. Like if I'm running 45-50 mph, it bounces in and out of overdrive, same at 30-35 mph. I have taken it to our dealership and they have looked at it at least 8 times. It doesn't trip any codes even when it is acting up. They say it is not the transmission, but rather an electrical interference problem. I can unplug the altenator and it runs fine until I plug it back in. If I disconnect the negative battery terminal it might be fine for a couple of weeks but then goes right back to the problem. I have put 2 new altenators on, have checked all the electrical connections I can find. It now has 173,000 miles and I have put up with this off and on for 4 years. I really like the truck, but am ready to trade it off!!! Any ideas?

 

Clean up all the grounds on the truck. Some one on here wrapped that single wire coming off the alt in tin foil or something like that to stop the interference problem. Mine was caused by a little corrosion on the neg bat terminals, cleaned all the terminals and problem solved.

 

I had a bad ground on my Ram and it did the same exact thing you are describing. The tranny's rely on a good electrical current toherwise they'll "hunt" for gears. Re-check ALL of your grounds, and don't forget where they meet the block. You may just be better off replacing the wires altogether, howevere I'd look for corrosion first. All I had was a little corrosion at the battery terminals and my tranny was hunting for gears. Cleaned em up, sprayed em with permatex terminal cleaner, and everything shifts as good as new.

 

Thanks for the input. I'll try that this morning!!

Joe

 

How did you make out?

 

I picked up a new cable (one was corroded BAD!!!!) this afternoon about 5 pm and didn't get to put it on today. I got the other ones cleaned pretty good. I noticed as I was taking a battery clamp off that I have a loose post (positive) on one of my batteries. Could that contribute to my problem?

Thanks again for all of the help!!

teamhamby

 

Anything electrical could cause an erratic tranny shifting problem. All I had was dirty terminals and my tranny was hunting so yeah, I'd say a loose post would do the same. The electrical system in these trucks doesn't seem real tolerant of and funny business that's for sure.

Clean evrything up, install that new cable, and get yourself a new battery and see how things go. I'm optimistic that you'll be pleasantly surprised.

 

Joe. . .if it is still hunting after you clean the cables from the battery you'll need to check the tranny wireing harness for chaffing and possable grounding out.

 

Mine does the same thing when shifting into overdrive under medium acceleration. I'll check the grounds. Hopefully its an easy fix. Thanks for all the good information.

 

I changed the cable and cleaned the posts and connections but didn't have time to get another battery yet. So far it seems to be perfect. I'm gonna go ahead and get the battery. That post is the one that gets the most corrosion. Seems like this might take care of it!! Thanks for the help!!

Joe