Lurch In Truck While Towing 5er

[jhpfennig]

I use a 2005 Dodge 3500 4x4 with a 48re to tow a 39' 5er toyhauler. Since I left home (Buffalo, NY) in August, the truck has developed a lurch or jerk. It happens only while towing and doesn't matter if the cruise control, Pacbrake or ATS Co-Pilot are on or off. It started out doing it only once each occurance but now may do it mutiple times. Have had it to 2 dealers so far without success. The only code logged was P0572 which is low voltage at the brake pedal switch. The switch was replaced but condition persists. Also TSB update #'s 18-022-07 (engine enhancements) & 21-006-07 (shifting enhancement) were done. I changed the fuel filter & added Power Service to the fuel tank. The transmission was serviced at 15,000 miles (now have 25,000 miles) and a Mag-Tec deep pan was installed. Not sure if it's engine or transmission related. It jerks so hard I'm afraid of thowing a u-joint. The tach barely wavers when it happens. The transmission doesn't slip while accelerating and the engine pulls good. I would appreciate hearing from anyone who has had a similiar problem and found a cure. Thanks.

 

[p-Bar]

Is it during shifting 1-2 ? if so TSB 21-009-07

 

[jhpfennig]

Thanks for the quick reply, but no it isn't during the 1-2 shift. It always happens in high gear without warning. Thanks again.

 

[KWilkinson]

My 07 5. 9 has an issue somewhat like that... Not quite coasting down a hill, just lightly on the throttle (cruise seems to do it the worst, seems to never completely "lift" off the throttle) it will sometimes start to jerk. I've also had the recent software updates, and I go in next week to have the 1-2 shift TSB done just to see if that takes care of it. My truck does it in any gear, any speed, loaded or unloaded.

 

[jhpfennig]

Thanks for the reply, seems we have a similiar problem. My truck will do it in or out of cruise, doesn't matter. I wonder if overfilling the fuel tank would cause it ? I usually continue filling the tank after the nozzle clicks off as I can pickup an extra gallon or two. It only happens when towing my 17,000 # 5er which makes me think it's the transmission ready to gernade. I wish the parts would fall off so I knew where to look. You mentioned having a 1-2 shift update done, what is the TSB # ? Again, thanks for your comments. Let me know if your find the "cure".

 

[phloop]

The TSB is 21-009-07.

 

[TRLRTRSH]

"It only happens when towing my 17,000 # 5er which makes me think it's the transmission ready to gernade. "



Thinking of other possible causes, Have you looked at your hitch? maybe the "lurch" you are feeling is not engine OR transimission related. After installing the new hitch in my 03 there was a kind of "bang" feeling every now and then. Come to looking for the source, it was the hitch not properly adjusted.

Just an idea.

 

[jhpfennig]

Good thought but the lurch seems to be coming from in front not in the rear. It almost feels like a momentary loss of power or the transmission slipping. It happens so fast & inconsistent it''s hard to diagnose or describe. I will however check the hitch. Thanks again.