04 Explorer jerking when coasting

[MelissaAmber]

I recently bought this 04 Explorer (v6 4.0) with 165k miles. It ran fine, nothing noticeably wrong. After a week I noticed that sometimes when I would reach a speed of 40 mph or greater and let off the gas, the vehicle would jerk. Sometimes it's a light jerking, other times it's pretty hard. I have tried to pay attention to what triggers it, but the only thing that seems to be a constant is that it happens after I've been driving a good 10-15 in stop and go traffic.
The first thing I thought was something was up with the transmission. Now, I didn't get any service records with this vehicle and of course it's the stupid design of not having a dipstick or a fill plug. I did not want to just go have this tranny flushed without first seeing the condition of the fluid to maybe judge if it had ever been serviced before. The disgusting black cherry colored syrup that drained out suggests it had never been done, or if it had, it was about 100k miles ago. I decided to skip the flush, not wanting to cause any uneccessary problems, but we were able to at least get 4-5 qts of new fluid in there with a little Lucas added to it. Still it jerks, which if the tranny really is the problem, is not surprising...it needs to be drained a few more times.
Secondly, the air filter was black so I changed that. Got the fuel filter changed and cleaned the fuel system. I had the transfer case and differential fluids changed as well. Still it jerks.
Tonight I disconnected the battery, as someone suggested to resest the computer. I will see in the AM if that did anything.
The only other thing I can think of is cleaning the MAF sensor.
I'm not getting any service engine light, and my O/D light hasn't flashed. And no, the motor mounts aren't bad. And no, one tire is not smaller/bigger than the others.
This could really be nothing to worry about it, but it bothers me. Especially since I'm about to move 1200 miles.
Does anyone have any thoughts?

 

[JoshMcMadMac]

How recently did you add the Lucas? It may be causing the issue, which should resolve itself with some more driving.

 

[04eb]

I'm curious about this as well. I notice it when I have the cruise on at about 65mph and am going down a hill. I have the rearend whine and the sound goes with the jerk. Usually a second or half second between jerks and the whine being intermittent.

 

[Ronin8002]

I saw your comment on tire diameter, but just to be sure, double check your tire pressures all around.

You might also try pulling the 4x4 fuses just to eliminate the 4x4 system as an issue...IIRC they are fuses 17 and 18 in the 4x4 fuse box on the passenger side of the engine bay (double check your owner's manual to be sure)

 

[MelissaAmber]

Jerking was present before we did the partial fluid change with the Lucas.
I'm thinking there could be a problem with the torque converter.

 

[MelissaAmber]

I will try removing the fuses. Tire pressure is good.
Ive been trying really hard to pinpoint what triggers it, and today I tried putting it in third and it jerked the whole time I was coasting while in that gear. I didn't get the chance to try second and first.
Any thoughts?

 

[JoshMcMadMac]

II have been told by a 5R55 specialist that Fords have a helluva time adjusting for coasting. It could be something engine related, like an ailing coil or dirty component. Try doing the same thing in neutral and see if that makes any difference.

 

[MelissaAmber]

I will try that.
I'm not 100% educated on all aspects of the transmission, but would a bad solenoid cause this? The thing is I haven't noticed any slipping or constant hard shfiting. There is a little hesitation when taking off from a stop sometimes, that's about it.

 

[JoshMcMadMac]

I will try that.
I'm not 100% educated on all aspects of the transmission, but would a bad solenoid cause this? The thing is I haven't noticed any slipping or constant hard shfiting. There is a little hesitation when taking off from a stop sometimes, that's about it.

A bad solenoid can do a ton of different, squirrely things, so I would certainly consider it a viable suspect.

 

[Mr. Wiggles]

Is it jerking front to back or side to side?

If side to side, with the whining I'd say it could be a bad wheel bearing... pretty common for expos with the milage..

 

[MelissaAmber]

It feels front to back. And with it only doing it in certain speeds, I don't think it's a wheel problem? Seems odd that if it was, it would stop as soon as the speed is below 39ish, and not also be jerking while accelerating?

Also, today I tried putting it in neutral when it started to jerk and the jerking stopped.

 

[05FordExplorer92]

My 05 Ford Explorer is doing the same jerking except mine is from side to side.....any answers? its more of a bother to me than anythin else

 

[BigRondo]

My 05 Ford Explorer is doing the same jerking except mine is from side to side.....any answers? its more of a bother to me than anythin else

Welcome aboard!!

Sounds like you could have bad wheel bearings. Don't let it go too long or the results could be catastrophic!!! :roll:

 

[05FordExplorer92]

thanks....it will do it when you step into the gas and then coast and while coasting as well....so your thinkin it may be wheel barrings?

 

[Miguel'sford]

Did you ever resolve your jerking problem with car?

 

[LoKo498]

Sounds like it could be the front differential. It happened 2 me twice. Maybe try to disconnect the shaft & see if that helps.

 

[ROBinGa]

My Explorer was surging and jerking pretty bad and it really worried me. It turns out my tires were on their last legs and the difference in circumference from front to back set was making the AWD mechanism try to compensate for difference in wheel rotation speed thinking the 4WD needed to kick in. This was happening at highway speeds mostly. I got new tires and it completely stopped that and drives amazing after that.

 

[apenland01]

I know the post is quite old, but the jerking on downhill with the cruise control on is normal. You can't really control that. The PCM doesn't quite want to downshift it, but it can't keep constant acceleration/deceleration, so you get a rhythmic pulsing as you go downhill. If it gets steeper, the tranny will just downshift to slow you down.