'02 F-150 7700 Super Cab, 5.4 auto with towing pkg. 107,000 miles... a lot of towing a boat and a travel trailer. Approx 1 year ago (89,000) was getting a rumble noise taking off from a stop. Took it local Ford and they flushed - rumble gone. Next, (March '08) was getting a "flapping" sound from the rear end. Back to local Ford and a new rear end (~ $2000.00). Now, at around 45 - 55 mph there is a jerking - almost like a manual trans when you need to downshift. Except this is an automatic and it's "at speed". If I accel, or take it out of OD, it subsides. Also, it seems to do it only after it has been driven a while, 20 miles or more. Especially on the interstate. Nothing when its "cold".
Went again to the local Ford and they said they couldn't find anything.
Grrrrrr.
I've got a long towing trip coming up. Suggestions?

 

I suspect that the driveshaft u-joints are bad. Last year, my truck started to develop a shudder on deceleration at 50-65 mph.
The seals for the u-joints were bad, which allowed water to get at the needle bearings, causing them to rust and fail.
Remove the driveshaft and see if the u-joints move smoothly. If they dont, that is likely the culprit.
I bought a new set of u-joints at Autozone for $20 each. Make sure you get non-greasable ones because once the driveshaft is on the truck, its almost impossible to get a grease gun on the zerks.
I bought greasable ones for mine and the only way I can grease it is with a pin adaptor that threads onto my grease gun.

 

I am having the same problem and when I take it out of OD, it goes away. I thought of u-joints too, but why would it not do it in OD too? At first I thought I had the typical rear-end clutch pack shutter and was about to buy the parts to do the job. Now, I think it may be something different. ANYTHING but the trans!!!

Any thoughts??

-John

 

I'm scheduled to take it back to local Ford Monday AM. I'll post what happens - and $$$!

 

It's probably your torque convertor "shuttering". My Grand Marquis was doing the same thing. Went to local NAPA store and got a tube of "shutter guard", added it to trans fluid and it has been doing fine.

 

i would bet the flushed and filled with MERCON not MERCON V

 

Have you ever replaced the spark plugs? Could be a coil going bad. If the dealer scans the ECM maybe it will show something.

 

Well... My F-150 is back and of course they couldn't make it act up. They ended up putting the computer on while they drove (I suppose) and it apparently put out a code that said cylinder #4 was "dumping". So, they replaced the coil pack, at just under $300.

We'll see! Thanks for the help... we'll see!

 

What you are describing sounds like the same thing I had. After researching it, I removed the trans oil pan and tightened the valve body bolts. New filter & fluid and it has never happened again.

 

Here is the probable answer to your 'lite load stumble'.
There is a bad coil, one with shorted turns that will not set a code beause it is not a hard fault. (it still works)
Tell the dealer you want a stress test on each coil to pick out the one that is low on output.
The reason it fails in this manner is as follows.
1 the fuel is cut back during OD lite load operation and make the air/fuel ratio very lean. The one bad coil can't fire it's plug under these conditions so you feel it as a miss.
2. the ignition timing goes advanced to make it worse.
This is all normal, operation until a coil fails full output then you feel it.
This is a common problem that few understand.
Print this out and take it to your dealer tech and even help him with something he may not know about, but should..
Been there and discovered all this.
Good luck. Let us know how you make out.

 

Thank you Bluegrass, i have a similar issue.

 

i also have been having this issue for along time too. i do not have individual coils though. i have an e-150 with 4.2 eng 6cyl. OD off it drives pretty well. ocassisonal shudder 35-45. impossible to use cruise cause it jerks a lot with that on going up any minor incline. with od on it always shudders 35-45

i have replaced the coil and the wires no improvement.

could it be the plugs. and does the lite load shudder occur when engine does not have individual coils?

 

I don't know, but a "coil pack" sounds like a computerized board of some kind - rather than an actual wire?

 

To expand on this, the EGR is called into operation during lite load cruise.
This means the fuel is cut back, timing advanced and the EGR is pulsed open to admit exhaust gas back into the air stream.
This results in a very lean mixture upwards of 20 to 1.
Any ignition fault that fails to fire the plug or a bad plug can result in a miss.
How sensitive a 4.2 is to this I don't know but would be possible if a coil pack fails in just the right way with low output voltage.
Worn plugs can also add to this stackup problem as well.
Some times new plugs seems to solve the issue only to come back again after 500 to 1000 miles after the plugs get some errosion and don't fire as well as new.
Since the fault is not a hard one, no codes are set because the fault clears as soon as more power throttle is called for and conditions change again.
Good luck, it's a sticker that has many stumped in the absence of a code.
.
This type of fault has nothing to do with trans shudder being the way it acts. Normally the trans is in electric lock (in od) up so there can be no slippage just in a short range of lite load operation then dissapear as load is increased.
Coming out of a very lean mixture condition with a sleight extra load is when the failure occurs from low ignition voltage on one plug.
.
It can get so bad that sometimes the PCM gets a signal back that interfers with it's signal processing and stops operaton all togather for a moment and that's when it feels like the key was momentatly turned off until the PCM get back to normal operation.
As stated, this condition seldom sets a meaningfull code because is not a solid hard fault.

 

2001 f150 5.4 BI-FUEL REGULAR CAB 4X4 7700.
Mine was doing the same thing. I noticed if I shut off OD, problem cleared up, also accelerating or decelerating cleared it up. I checked trans fluid and added about 3/4 qt, plus put friction modifier in rear end.
My son said just keep driving it and problem would clear up as the computer had to relearn. I'd recently had the compuvalve replaced.
The shudder was so bad, especially right around 62 mph, I thought the transmission was going out. However, it did clear up in about 100 miles. I'm still not sure what the problem was, if it even may have been stiff u joints that loosened up.
It runs a and shifts smoothly now, no more shudder. Go figure.
Good Luck with yours,
Max
P.S. Another thought could be moisture around the plugs, which dried out, but it must have been alot to have not cleared up for that many miles.