Jerking while towing

[luther's 2008]

Mine just started doing it towing a 5k load....210 Spartan Tow tune AND PMF traction bars....first time I've noticed too.

 

[PSD-BLACK-CLOUD]

Mine quit when I got traction bars. But it would do it loaded or unloaded with or with out a trailer.

 

[09wyoblue]

Thanks for everybody's input. I think I have come up with a redneck way to temporarily limit axle wrap ie simulate traction bars and will give it a try hauling HEAVY loads later this week,:jammin:

 

[Breaking Habits]

Just an FYI, not just the addition of any traction bars will fix axle wrap and bucking.

My fabtech bars didnt do a damn thing to help, just make it slightly less severe.

One Up Offroad traction bars, flawless shifts and take off, no buck, no harsh loading/unloading

 

[09wyoblue]

Just an FYI, not just the addition of any traction bars will fix axle wrap and bucking.

My fabtech bars didnt do a damn thing to help, just make it slightly less severe.

One Up Offroad traction bars, flawless shifts and take off, no buck, no harsh loading/unloading

Thanks for your input Jared! That's the kind of info I was hoping for when I started the thread.

 

[KPBJJ]

Mine was doing the same thing. I had to much play in my receiver so I put duck tape around the shank to make it fit nice and snug and it helped a lot.

 

[Phiber Optik]

Any update on this? I have gearhead tuning and this happens to me unloaded when accelerating 40% throttle or more when the convertor locks in 4th gear the truck bucks violently until I get out of the throttle. It feels like more then the leafs bending during axle wrap.... Like tuning or convertor related.

 

[luther's 2008]

I haven't had an issue since the first time. Shifts remain smooth, and I haven't experienced any bucking.

 

[dasboot]

I used to pull a 25' ft fifth wheel with a GMC 2500HD gasser 350 sclb. It pulled it like a charm. I got my PSD and running it down the hwy It was jerking so bad that I thought it was the truck. Of course certain stretches of this hwy would beat you to death in a bad suspesion vehicle. After all my research, I came to the conclusion that it was all in balance whether it was weight or being level when hooked. Anyways there were no tunes or traction bars in any of this just in case I got off the subject.

 

[golfer]

lots of ICP/RP will cause an 'on/off' trailer hitching...and with a trailer...you're a biiittttt more 'into' the pedal than unloaded..which will shift you up into a part of the (fueling/ICP) map which probably has more RP than is needed for steady state driving/towing...

if the 'trailer hitching' is worse rigggght at the transition when cresting a small hill...where you are barely on the pedal..almost feathering it...

then have your tuner lower the rail pressure at light throttle/pedal position...or move to a lower hp tune, which will probably have a less aggressive RP ramp in the (tuning) table.

 

[tbsimmons]

My dually will do this when I am going right around 33-35 mph with very very light throttle while I am towing through a town or so. I have 4.88's and 34" tires for comparison.
What I do know is either dont let the TC lock, with is in the 33-35 range for me or go faster if possible.
I tow on with the tow tune when towing a 18000#+ fiver, gross is in the 29000 range. I dont think I have ever felt it with my car trailer which with my car is about 7000#, even towing with the X-Street.
When my gross is less than 20,000 I usually use the street tune if I am going to be in towns or a lot of hills or the X-Street if it is mostly highway.
I might try the Mild Tune some time. I liked it unloaded last time I loaded it, but the mpg was less that the X-Street but the throttle is much more linear.

I use firmer than stock with stock lock with every tune I run. I tried the later lock but felt it shifted to easy for me.

 

[03sixspeed]

My truck does it with the 250 or higher tunes either towing a heavy bumper pull or ANY gooseneck. Even my empty horse trailer it will jerk with right after the converter locks at 45 mph or so up until it shifts into OD. With 210 and under it does fine, it is completely throttle sensitivity in my case, the lower tunes just work better for towing, but light trailers the 300 tune is no problem.