Have a F350 2009 that is jerking/surging at certian speeds, but not all the time. Transmission fluid is ok, no apparent leaking. Anyone have any clue as too what may be causing this? Begins to jerk & surge between 55-65 mph, then gets worse at all speeds; does not happen all the time this is when towing and not towing. After stopping for the night I can drive about 1,000 miles or less (mostly hwy) & it will start again. I recently had the dpf filter removed; I am now using the H&S Black Maxx tunner. I transport 5th wheels & Travel Trailers from mfg to dealers therefore most miles are on hwy. I have 250,000 miles on the truck. I change fuel filters every 20,000 miles & Just changed them again; did not help. Could tunner have anything to do with this problem? Thanks for any help.

 

Even the smartest people on this site will probably need more info to help you. Does it happen while towing or empty or both?, at what speeds?, ect.

 

What he said (not that even close to being one of the smartest people on this site) you're gonna have to give way more detail; stock or modded, etc., etc., etc. You'll get great advice and help here, but you're gonna need to give more details first...

 

Yeah, I am not the closest to being able to figure it out either. So subscribing to your issue.

So fuel filter changes when? Use OEM?

 

Im not sure if you figured it out yet, but I had the same problem with my 6.4 with dpf delete and Black Maxx tuned. Its related to the shift points in the H&S tunning. I emailed them and tech support suggested (for towing, which they couldent suggest to do because its intended for off road use!) to download Shift point 2, medium. It worked great. The stock tune on the H&S black maxx is set up for racing. You can experiment which transmission tune is best for you. Setting the cruise control will also fix the problem if you dont want to re tune the transmission

 

Wow, that's very interesting. So, the STOCK tune does not return the truck to stock. Makes a fella wonder why they call it the stock tune.

 

No the Transmission tunning that come "stock" or installed standard shift points on the balck maxx are fast shifting for the transmission Schedule 1. (Not related to stock tuning.) It related to shifting points and when the TC locks up. The standard shift point are more race performance driven than for towing, Shift schedule 2, medium fixed my problem. Visit The Black Maxx H&S website

www.hsperformance.com/6-4l-powerstroke-custom-transmission-tunes/
Shift Schedule 1 with Medium shift speed is preloaded from H&S and included in the “latest software” and “HOT DAMN 300″ main downloads. Use these custom downloads if you would like to change the shifting. “TC lock” means that the Torque Converter has locked out and is no longer slipping. This creates a direct connection from the motor the transmission, much like a standard transmission would. You can monitor TC lock status on the Black Maxx and Mini Maxx units right next to the gear display.
You have two choices:
1 Pick a shifting schedule. There are 2 shifting schedules you will choose from.
Shift schedule 1:
1 – 2 – 3 – 4 – 4+TC lock – 5+TC lock
Shift schedule 2:
1 – 2 – 3 – 4 – 5 – 5+TC lock

2 Pick a shift point – Low, Med, or High
Shift schedule 1:
For Shift Schedule 1 tunes, the LOW, MED, and HIGH modifiers will affect the 4th gear TC lock point, 5th gear shift point, and the 5th gear TC lock point.
Shift schedule 2:
For Shift schedule 2 tunes, the LOW, MED, and HIGH modifiers will affect only the 5th gear torque converter lock-up point.

 

So you have to modify the tranny? You can't run: stock tune/DPF delete/stock tranny? Is the Mini the same? just courious.