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Shudder in Auto trans

4454 Views 41 Replies 15 Participants Last post by  Rrloren
While cruising at 55-60 MPH if I let off the pedal slightly-not all the way- and then depress the pedal normally to speed up, the truck shudders for a second and then all is fine. Is bad enough the passengers can notice it. Actually shakes the truck fairly good.

If you let off the pedal fully and then depress it this never happens. I need to be a straight level road and can duplicate the problem.

Engine RPM's do not drop of fluctuate. Does not seem like the torque converter is unlocking and locking, but possible.

Took it to the dealership and they could not duplicate it. They updated the trans controller and the problem is still present. I'm sure I will need to drive the truck for them to make it happen.

Curious if anyone else has experienced this or knows what it might be?
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omnc 449 any tuner or mods on your truck
No mods. All stock. I have larger than stock tires with a leveling kit. Its at the dealer now and they say there are no codes on the computer and want to drive it home tonight to see if than can duplicate the prob.
there going to say that they cant duplcate problem , take them for a ride as i`m sure you know your truck better than they do and can make it do it
and you were right!!!! They couldnt duplicate it but the did a TCM flash update. Its running fine right now but I'll test it out this weekend. Crossing my fingers!
While cruising at 55-60 MPH if I let off the pedal slightly-not all the way- and then depress the pedal normally to speed up, the truck shudders for a second and then all is fine. Is bad enough the passengers can notice it. Actually shakes the truck fairly good.

If you let off the pedal fully and then depress it this never happens. I need to be a straight level road and can duplicate the problem.

Engine RPM's do not drop of fluctuate. Does not seem like the torque converter is unlocking and locking, but possible.

Took it to the dealership and they could not duplicate it. They updated the trans controller and the problem is still present. I'm sure I will need to drive the truck for them to make it happen.

Curious if anyone else has experienced this or knows what it might be?


I sort of have the same thing that your describing.I would describe it more like a single SKIP in the the engine almost like you hit a small bump in the road as soon as you step on the gas.
TBOLDUC-Sometimes it is just a single skip like you described but depending on how back it happens it can be two or three skips/shudders and then it is fine.

The weird thing is that it does not happen if I let off the pedal completely. I have not taken it to another dealer yet. I need the truck so time is always an issue. I will try to get it in next week and test drive it with the mechanic so I don't get another "Could not duplicate". I like it when they dealers say that!!

It has gotten to the point that I can tell when it is going to happen and how bad.
Well i guess i should have searched this topic. i just posted yesterday about my truck having this issue and diddnt realize there were others. Sorry guys. I am having the same issue as you guys to a T and havent a clue what is up with it. My truck is bone stock with only the dpf delete. I am going to experiment with a few things tomorrow and will let you know if any good comes from it.
A lot of trucks do this - there are tons of threads on here about it. Nobody can nail down what it is. But its mostly prevalent on trucks with power adders, when the engine is lugging at or below 1200 rpm's. It'll shake like you are going over washboard.

Mine did it once and never did it again. But I also make a conscious point to not lug the motor.
i agree with the lugging. i took my edge off and still get a light surge in 6th going 55-65mph. but if i run the mess out of it i dont get the surge for awhile. i dont get any shaking or anything but i do get a feel like a hickup. i was told it may be the map sensor staying sooted up.......... ive come to realize this 6.7 is more of a pain then an enjoyment.
So i Compcowboy suggested to me to unplug the EGR and run like this to see if that would take care of the shutter. Well from the testing i did yesterday i would say yes it did take care of the shuttering. Best i can figure is that when cruising down the road and rolling into the throttle the EGR system is not backing off enough to let more oxygen back into the system. :confused013: Maybe it is something in the flash that isnt working correctly with that system.
So i Compcowboy suggested to me to unplug the EGR and run like this to see if that would take care of the shutter. Well from the testing i did yesterday i would say yes it did take care of the shuttering. Best i can figure is that when cruising down the road and rolling into the throttle the EGR system is not backing off enough to let more oxygen back into the system. :confused013: Maybe it is something in the flash that isnt working correctly with that system.
are you running a 68rfe?
Yup :thumbsup:
Same problem

I am having the same problem with my truck. I have tried several things. Was talking to a friend last night and his truck does the same thing too. He called his mechanic that does some work for him and he said that this problem was almost always a switch or sensor, he couldn't remember which one, but he is about to take the truck to him to have it replaced, so I told him to write it down. I did have a guy at the parts house tell me that alot of times the crank sensor would occasionally flake out, momentarily, and that the xmission wouldn't know what gear it should be in causing it to shudder. I put my code reader on "record" and drove the truck yesterday, trying to duplicate the problem to catch something abnormal. When viewing the rpms of the truck it shows two readings which are always within a few rpms of each other. Around the time of the skip it recorded those two readings about 350 rpms different from each other.
Took the truck into the dealer this morning. I requested to have the technician drive with me-no more Could Not Duplicate BS. I was able to make it happen several times while driving. Tech initially thinks it may be the torque converter but they need to do some testing. I will update this when I get any new information.
I had this same problem. I unplugged my EGR a few thousand miles back and havent had it since.
I am starting to lose my mind and patience.

Now I mentioned earlier that I drove it with the technician on the 15th in the morning and that I was able to show them what the truck does. They called me back that night and said they Could Not Duplicate it and I could pick up the truck.

I said it happened that morning with the tech--how can you say Could Not Duplicate?? They said they were unable to make it happen when they drove it and could not find anything wrong.

So I go back there this morning and drive the truck with the tech and the Service Manager. I was able to make it shudder but they still did not pick up on anything that is wrong with the Star Scan tool. They still have the truck and are going to drive it again.

I like stealerships.

I think it may be time to disconnect the EGR if they call and say they Could Not Duplicate it again. This is becoming my favorite saying.
The latest information from the dealership is that it is the way I am driving the truck (using the throttle).

The tech recorded various parameters while this occurs and sent it off the Chrysler to see if there is anything wrong...Nothing wrong with the readings.

The thing I want to know is if it is the way I am using the throttle how come it happens with the cruise control on?

Just another stressful day with the dealership.

Sorry for the rant. Needed to vent a little...Sounds like a Coors Light commercial.
when it does it is it in 5 or 6 gear?
It will do it in 4th through 6th gears that I have noticed. I am beginning to think this is more engine/fueling related than transmission related.

The Service Manager is supposed to call me tomorrow. I will see what kind of BS he will try to feed me.
I think your right, althoug 4th gear I can feel torque converter lock up the most when under accelaration
4th gear in my truck is a very soft shift. All other gears you can feel a positive clutch engagement. 4th feels different than all the other gears upshifting and downshifting. I asked the dealer about this before and was told this is normal for this gear. I have nothing to compare to so maybe that is the way it is. It holds the power but just doesn't feel right.
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