Hi all,
I have been lurking this site for awhile now as a "tool" to help fix some minor and not so minor mechanical problems on my 96 ram 2500 5.9l 360. Been really fun and rewarding. I am really stumped on this one however. In overdrive, coasting with light throttle between 50-55mph the truck jerks like it wants to shift but doesn't unless I give it good throttle then it will shift fine. Everything else shifts fine/smooth except in overdrive between 50-55mph. I notice it more when towing. Everything shifts fine and runs normal when I turn the overdrive off. I do not think it is the transmission more of something with the engine/tranny not being in sync. Just changed transmission fluid/filter-still having problems. The only thing I could think of would be the TV cable being out of adjustment or bad linkage. Could it just go out of adjustment over time? is this common?
Thanks!


Well I took the rig into a transmission/auto repair shop that had it for three days and all they could come up with was to take it to the dealership and have them reset the pcm and tcm. So $47 and and a free car wash later problem still there. After doing even more troubleshooting on my own I finally decided to just give the truck a good tune-up. New spark plugs, wires, cap,rotor, coil and even added some fuel injector cleaner into the gas tank. The whole job took me about two hours. Now I am happy to say she is running like a top- no more jerking and hesitating. Thanks to all who replied to help me out. Hopefully this helps somebody.

 

At that speed, you should already be in overdrive, so I think what you are referring to is the TC lock-up.... try this: turn off o/d (button on the dash in 94-97, on the shifter in 98+) and count the gears. Should go 1-2-3-lockup. Do you feel the same sort of jerk upon the 3rd-lockup "shift"?

If yes, that's your TC clutch... which I believe requires replacement of the entire torque converter (someone with more knowledge will hopefully happen by to confirm/deny this)

In any case, the TV adjustment doesn't have anything to do with it, you'd feel that in all shifts (most notably 1-2 in my experience). O/D engagement is computer controlled (on the later model 96+ trucks)... What year is your truck?

EDIT: oh, and just for future reference, threads like this one belong in the tech section (the first board that pops up when you click on 2nd gen ram). You'll get faster responses over there. Wait on jasonw to happen by, he'll probably move it for you.

Welcome to the forum!!

 

If it's not the converter clutch engaging and disengaging, which it might be (and a scan tool's the best way to find out), it's probably a misfire. Most of the time, it's a misfire. Overdrive and low engine RPM bring out the worst in each other.

Also, don't tow in overdrive. Not good/very bad/make transmission puke.

 

I hooked up my little portable scanner and there are no codes signaling a misfire. The truck is from 1996.
Thanks

 

Won't always set a code.

Find a nice straight stretch of road, that isn't real busy. Accelerate slowly from a dead stop, and count the shifts. (O/D enabled) Right about 45-50 mph, at light throttle, you should hit fourth gear, and very shortly thereafter,TCC engage. If at that point, it starts shaking like it wants to fall apart, that's an engine miss.

 

What I meant was a full-on diagnostic scan tool, one that will show you when the PCM is commanding a converter clutch engagement, so you could tell during the event whether or not the clutch was being told to engage.

 

When you say "shaking like it wants to fall apart", you mean like youre driving on the rumble strips?

 

It is not shaking like on rumble strips just jerks like it wants to shift but won't until I give it good throttle. Yes it happens during tcc lock up. I also forgot to add that I am burning through alot of coolant. There is a coolant leak up around the thermostat area-I think maybe around the timing chain cover or blown intake gasket? I replaced thermostat and gasket so I know it is not coming from there. The truck is running a little warmer than normal too. Usually the warmer the weather the warmer the truck gets. This is turning into one of those transmission or engine problems. Or both!!

 

If you let your truck overheat, even a little, over an extended period of time it will have negative side effects on the tranny (assuming you have the stock in-rad tranny cooler). Get that fixed before it causes more problems.

Take the truck to a tranny shop (or any shop with a badass scanner), have them hook it up to a scanner and reproduce the problem to determine if it is in fact the TC clutch. You will not be able to do this will any run-of-the-mill scanner, and it will not necessarily set a code.

The goal is to see when the PCM commands lock-up, and compare that data to when the problem occurs. If PCM says lock, and that's when the truck shakes, you will need to replace the TCC.

EDIT: as far as the coolant leak, look at the little peice of hose that comes off of the intake, runs under the accessory bracket, and goes into the top of the water pump. It's kind of hard to find if you don't know what you're looking for.

Perhaps a pic of where the leak resides could help us locate its source.

 

sorry too get back to this so late-have not had time to get to a shop yet. But a few more things I figured out...
After driving the truck around for awhile I notice the jerking and bucking after I de-accelerate a little from tcc lockup then slowly accelerate again. At that point during light throttle it jerks. Maybe its not kicking out of lock-up? Everything shifts fine and smooth all the way through into tcc lockup when I start out. Just when I let off the gas to slow down and accelerate again it jerks until I get over 55mph then runs smooth. I replaced the tps and thought for sure that was the problem because the old sensor sounded like it had loose parts inside-no dice.
Hopefully this helps out a little more.
Thanks a million for all the help so far..