Towing herky jerky

[David Schwarz]

I've now spent the last couple of days towing my car (3100 lbs) and trailer (1700 lbs) behind the used F250 (460 cid) I bought. It seems that when I'm traveling down a road, there is a jerky movement to the truck, almost like the transmission is slipping and then catching (I have an E40D AT). The tranny has traveled 40K miles since it was rebuilt, and without the trailer it drives fine. I know the description I gave leaves lots to be desired, but does anybody know if this is normal or abnormal. The sensation is there whether I keep the truck in second, or have the OD turned off. In addition, it's not there all the time, but seems to be more pronounced during the first few miles of driving.

[ModMech]

Does this happen in all gears (1,2,3, and OD), or just 2&3?

[David Schwarz]

Originally Posted by ModMech

Does this happen in all gears (1,2,3, and OD), or just 2&3?

I haven't driven it enough to say at this point. Most of the driving has been in either 2nd, or with the OD turned off (1st through 3rd I believe).

[RexNfx400]

The E4OD has a lock-up clutch inside the torque converter(TCC). That means to say that, when this locks, it creates a solid(for the most part) connection from engine to the rear differential. Any missfire at all, AT ALL, will be felt once the converter locks up. I'm not talking about a missfire that you feel, like when your pulling spark plug wires off chasing a fouled plug.

When this converter is "locked-up" it (you) will feel, lean missfires, weak secondary ignition spark, too far advanced timing, injector problems, bad gas, stuff like that. I guess simple to say that. The engine has to be running perfect or you will "feel" the problems once TCC locks.

[David Schwarz]

Originally Posted by RexNfx400

The engine has to be running perfect or you will "feel" the problems once TCC locks.

Thanks for the explanation Rex - now I have something new to add to my knowledge base. So how do you know when the TCC is locked; in other words, what causes it to lock?

[ModMech]

What Rex posted is mostly true.

The Torque Converter is NEVER at 100% lock, but it slips a little to "absorb" driveline vibrations. It also generates a lot of heat when pulling, which is why they tell you to "lock-out" OD, to reduce the heat.

The EEC commands lock up in 2, 3, and OD. However, unlike the AODE/4R70W RWD transmissions, the E4OD/4R100/5R100? the T/C *can* be locked in ANY gear, as it is not hydraulically or mechanically prevented.

The EEC will command the T/C to unlock if the trans fluid temp gets too high, or if it detects "excesive" T/C slippage. This might be related to your problem.

[RexNfx400]

The E4OD has no PWM TCC untill the 4R100 diesel.

If there was any slip in the tranny/converter the OD light should flash and set a code and go high line(harsh shifts). If TCC was commanded off then there would be no herky-jerky also, don't ya think? Weak springs in the dampening maybe, once TCC locked.

I would say engine runability.

Just trying to help

[ModMech]

That's good to know. I'd been told that ALL Ford's electronic A/Ts had a PWM TCC sol.

You learn something new every day.

[RexNfx400]

Originally Posted by ModMech

You learn something new every day.

Ain't that the truth

[David Schwarz]

Originally Posted by RexNfx400

I would say engine runability.

Just trying to help

I'm going to start by replacing the plugs and changing out the oil. The plugs that I was able to find at Kragen are the Bosch 4208. Is this the best choice for this truck? Also, Ford sold me an FL-1A oil filter, which is the same as I use on my 5L motor. Can someone confirm that this is the correct filter? Finally, how many quarts of oil does a 460 require? The owners manual says 5Q, but that doesn't sound right.

[RexNfx400]

PH8A, 51515, 85515, FL-1A Its like 302 to 460, its all good. Start with 5 qts, start it, run it for a minute, then shut off and check and top off.

No U-groove or platnium junk... JMO. Maybe its too late but dont put in the high dollar plugs.


Delco, Autolite or Champs will do just fine.

Do not forget the secondary cables, cap rotor fuel air and pcv(don't be too lazy)

L8rs

[David Schwarz]

Originally Posted by RexNfx400

Do not forget the secondary cables, cap rotor fuel air and pcv(don't be too lazy)

L8rs

What do you mean by "secondary cables". Are you refering to spark plug wires? I did notice that the cap and rotor look like they're due. The pcv valve is an easy one as well so I'll take care of that one.

A total of 6 quarts topped off the engine, but while it wasn't leaking at all before, now I have a leak (I used 10W-30, which is what it had before). I guess I'll have to figure out where it's coming from.

While we're on the subject of tuning, what timing should I run for this engine?

And the last question, the PO had a non-OEM cat put on for the smog check (which he normally then took off right afterwards). Right now it's on there, and it's pretty tiny. I can also smell some sulfur, so it's probably in need of replacement. Will I do any engine damage if I run the current cat for a couple more months? I need to free up some funds to have the exhaust replaced.

Thanks for all the help so far.

David

[RexNfx400]

Indeed spark plug wires

The timing is adjusted by the computer system. If timing has been messed with, then base timing has to be reset. This is more than just setting the timing.

Even the big OEM Cats will plug. If its some little cheesy thing well, its hard to say how good it is or how long it will last...

[Cessnadriver]

[quote=RexNfx400]The E4OD has no PWM TCC untill the 4R100 diesel.

How about a 1997 F-150 XLT, 4x4, Off Road package/4.6L V8?
Is there a TCC module external to the trans. I have heard of one from E-Plate (Whoever that is), that modifies the lock-up points in 5 mph increments.
Thanks

[badasstour]

my truck does that and it has a stick in ihave never been in a truck pulling a trailer that didnt jerk its normal