Occasionally and at certain speeds in 3rd and 4th gear my automatic transmission seems to 'jump' into and out of lockup. At around 30mph in 3rd it will do it and the tach will show a momentary increase in rpms. It only happens for a fraction of a second. It may only do it once or it may do it 2 or 3 times in a row. At around 45 to 50mph it does the same thing in 4th. It does not happen when accelerating or decelerating, only when I am holding a steady speed. Most of the time it is OK, sometimes it is not. Either it will be OK all the time on a drive or not OK right from startup.

I had the trans. checked at the local dodge shop who do a lot of diesel pickups and they could not find anything wrong.

Hope someone has a solution as I don't know if I should worry about it or just keep on driving.

 

Check this thread out. I posted what worked for me in there. Was just wrapping the major wires in duct tape (aluminum foil adhesive tape, from home depot)
https://www.dieseltruckresource.com/...d.php?t=184206

 

Check your grounds and fluid level. What finally fixed mine, still does it once in a blue moon was I put in an extra quart of ATF fluid over the full line why I don't know, maybe I read that somewhere but can't remember. I wrapped the wire from the pass battery to the alt, I believe it's a black with orange tracer, with tinfoil and electrical tape. That was all.

Sounds silly but that's what stopped mine from doing it all the time.

Good luck as it was VERY annoying when it would happen all day long at 35mph and 45mph.

Now it's about once a week on hunt and done. I've had the trans serviced since then and it seems like the dealer overfilled my tranny by the same amount. I know it's electrical noise but maybe there was something to the fluid, maybe not.

Good luck.

 

It may be a brake switch. Test by very lightly raising brake pedal and see if issue decreases. The switch is perhaps 15 dollars.
Mine had a plastic sleeve on pedal that was wrinkled and made switch very sensitive. There are three switches in Brake switch, so brake light is not giveaway. Also look at AC compressor pulley for wiring being worn by pulley, and causing feedback. Output shaft RPM sensor a posibility.
Not very high on al foil shielding thing. Clean and tighten cables and check for corrision in cables. Overfilling trans is not a fix.

 

I have a buddy with a simular problem right now. The foot under the brake pedal is a good idea, as well as covering wires. Could anyone provide pics of there covered wires?

thanks

 

Just reset your apps. Nothing wrong with doing that every 6 months or so.

It beats doing all that other stuff.

 

Puke

How do I reset the apps?

 

I don't give good instructions...so please do a search and veryify after I tell you.l


1) with your park brake ON, unhook your negatives to both your batteries so your truck has no power.

2) now turn on the key, turn on the lights, and everything else. You want to drain it completely of everything resembling power.

3) let it sit (with everything ON) for at least a half hour (I've tried 25 minutes and it didn't work..so now I just do it for an hour or two).

4)Turn all the stuff back off again and hook the batteries back up.

5) Turn your key on (but don't start your truck) and push your accelerator pedal all the way down and then let it off all the way back.

6)Your apps is now re-set.

What you are doing is taking away the existing "learned" memory of it by depleting all the power that keeps the memory...And then when you hook everything back up it automatically re-learns it the first time you push all the way down and back again.

If it is your apps. that is wearing,...then eventually you will need to get a new apps. because dead spots will show up in your pedal, etlc,..For me, an apps. went about 120,000 miles and then I replaced it. But I learned a long time ago that I should just plan on resetting my apps twice a year or so. Otherwise...you can always take it to a dealer and they will proably charge you 80 bucks for reflashing your computer... And also keep your truck for a half a day while they are doing it.

There is a permanent solution to the "hunting" problem of the trannys...Michael Emjay had made something called a strategy controller, but he died and it is no longer available. I read somewhere that he found out that it was dodge being stupid because they didn't shield something or other...so he had the permanant solution...and you could also set it to shift gears where you want it to.

OK
Enough rambling.

 

This may be caused by the Torque Converter Clutch (TCC) unlocking and locking when it should be consistently locked. The cause of this erratic operation has been identified as electrical noise from the Throttle Position Sensor (TPS) or Alternator. There is a flash for the PCM, TSB 18-02-99. also Chrysler recomends running a new ground from battery to pcm.

 

I just put in a mystery (lockup) switch. I can no control the hunting y'all are talkin about. Although the extra quart method did help quite a bit.

 

i have the same problems as above plus while idleing it jumps 50 or 60 rpm's constantlly the tac moves up and down

 

What about the "mystery (lockup) switch" fordkiller43?? how it works? where can buy one?

 

Do a search. And ATS and a few others sell Torque Converter Controllers. But a mystery switch is the cheap way but yet very effective.

 

quit chasing your tails...buy a noise filter from dtt and be done with it.............about 40 bucks,and will fix this.......bama

 

Many thanks to all of you for your suggestions. However, can17 had an earlier post related to the apps and seems to have hit on the right answer for me. He had sprayed contact cleaner on the apps plug to clean off corrosion which was causing a poor contact and affecting the transmission.

I did this two weeks ago and have tried many times since then to make the transmission 'jump' in and out lockup. I have been unable to make it act up.

Those of you having similar problems may want to try this solution. A can of contact spray from Radio Shack and a half hour's work is a cheap solution.