Aight. This started a few months ago. But was a rare occurrence. Lately it's been more common and will happen 3-4 times on my 1.5 hour commute.

Weird part is, once in a while I NEVER experience it. I could go a week without it happening. But it always comes back.

It's a jerking/bucking feeling. It's kinda like hen you go over a large bump and the rear skips to the side a bit. (If you have worn leafs you know what I mean) however when this happens the truck doesn't skip so it's not road bumps. Happens on smooth roads, bumpy roads, dry roads and slippery roads. Happens going fast and slow.

I can't seem to determine a specific thing that may be causing it. It's not speed, it's not rpm, it's not road condition or weather. Cause it doesn't matter what those variables are, it will happen.

Now, there's no codes, rpm doesn't fluctuate when it happens, it's just a quick jerk/buck ranging in severity from "oh I ran over a frog" to "holy **** I ran over a downed tree"

Ok, the tree thing might be an exaggeration, but it can be pretty intense at times.


Any ideas? Anyone had this happen? Is my Torsen shitting the bed? Is this due to the whistling pinion bearing the dealer says is fine? Chipped ring/pinion teeth? Transmission issue?

I have no clue.

06 fx4 level II. 4.0 auto Torsen LS rear. Factory 4.10 gears.

 

Torsen is a word I don't ever want to hear again. Have you changed your plugs? Is it happening when accelerating?

 

It's happened a few times while accelerating. But it's mostly when cruising at speed.

I haven't changed the plugs since I've had the truck, it's about due for a plug change. So I'll try and get that done ASAP.

Doesn't seem like a motor thing to me though. If that even makes sense. But then again, I'm hardly a mechanic. Yet. Lol.

 

Oh and I love the Torsen lol. As long as this isn't the Torsen acting up at least.

It's never let me down yet.

 

I'm not a fan.


The reason I asked about the acceleration is that I chased down a bucking problem with my truck for over a year. I put new plugs and wires in it and it went away. At least I thought. It came back about a month later. Finally got a misfire code. Checked the plug, and it has a hairline crack in the porcelain. Put a new one in and it happened again a little while later. This was when I learned that these trucks don't like anything but motorcraft. Everyone told me to run autolite replacements, but those are what was causing problems all along.
They are really easy to change out, so if you are close on your mileage for a change, I would say go for it.

 

I'll order up some oem plugs/wires and go from there.

When funds allow I will be totally revamping my rear/front end.

Haven't decided what I'll do with the front yet, but rear will most likely get either a 9" or a 9.75" from a newer f150. So even if it is the Torsen or the rear end. As long as it holds on till summer in good lol.

I've had the truck for 50,000 miles so far. Since feb. 2012. Have had zero issues this far aside from things I have caused myself.

 

I knew that rearend was going to fail so I just drove it. Howled for over a year before it finally snapped. Hopefully you get your problem figured out. Like I said above, I replaced plugs/wires, IAC, MAF, coil pack, changed out rearend fluid, and a trans filter. Just to find out it was those crap plugs the whole time.

 

Yeah mines probably due for some replacement **** anyways. Just figured id ask to see if anyone knew if it was something else.

Truck has 193,000 kms on it. Convert that to miles if you wish. On I'm assuming original **** lol. Bought it with 113,000 lol. Hasn't even been a full two years yet.

 

'02. Gotta love 'em! lol.


Yeah, I had a cracked porcelain issue with my brand new engine. Missed and coughed and fell flat on it's *** under any marginal load. His condition sounds different than what I experienced. But judging by his KM's, his should have been done 32km ago. And that's a stretch IMO. Ford says 100mi (160km) and that's crazy me thinks.

Transmission freaking out? My old man had a really low mile Buick that would shake like hell every once in a while in final gear. Few months later, trans was toast.

 

Now that I think about it. It quite possibly could be that it only happens when in OD. If I catch it doing it tonight I'll turn off od and see what happens.

 

update:

it hasnt done it a single time since i made this thread lol.

and ive done nothing to the truck yet. it has been a lot colder lately though (-40 to -45) its sposed to start getting a tad warmer so we will see if it comes back.

 

alright, its doing it more frequently now, notice it far more when travelling around 55 mph. no matter if im in OD or not, it happens when going faster, and slower, but no where near as often. seems to be the sweet spot for it. makes me think its not engine related (never truly thought it was, feel it way more in the seat than the wheel)

im going to tell the dealer to open it up and take a look when im in for an oil change. honestly i kind of hope its something they did. so its covered by warranty lol. ******* dont know what theyre doing.

 

I had the same problem on my 09 Ranger 4.0L and it turned out to be my differential pressure feedback EGR sensor. This sensor regulates the EGR to open but when they start acting up it will open the EGR valve at the wrong time causing your engine to stumble or bucket. Part # 9J460 got mine off ebay for $30 as the ford dealer wanted $75. Just something to consider.

 

Do you live where it snows? I had a problem with my truck bucking/jerking but only when it snowed out, and at cruising speed. pretty sure it was the air filter, i replaced it about 3 weeks ago and it hasnt happened since. Lots of other people had this problem same as me, and the air filter fixed it for some other people too. good luck