02 FX4 Supercrew with 4R70W.
165k miles
~12k since trans flush, 8 plugs changed and 2 Coil assembly replaced.

Truck shudders when pulling ~2200lb horse trailer. Did it once before and the dealer performed the above services about 12k miles ago.

Seemed to help.. until now. Towed 1k jet ski ~12 times for both short and long distances. Towed the trailer (2200lb empty and ~3100lb with pony) 3-4 times since then. Didnt notice anything then.

Is there a way to determine whether its a trans vs engine (coil?) issue? Since service did both - I cant determine from that experience.

Circumstances prevented checking fluid but will.... fluid last checked <2k miles ago.

Just thought of related question - did the tow pkg come with tranny cooler?

Thanks..

 

Well, these transmissions are known for a shudder when the fluid gets old, but that shouldn't be the issue here. Does it feel like you're driving over rumblestrips?

 

No -not really. I dont feel much through the steering.. but sometimes it almost feels like wheel hop.

It occurs pretty much at any speed - I went as high as ~60. Accelerating, decelerating, steady-state, OD on/off.... heck - i even put in N and coasted and felt it a bit.

I just dont want to throw $$ at possibilities till it gets fixed...

Thanks...

 

Look at the possability of drive shaft U joints or a dry trans output shaft to yoke spline.
Good luck.

 

Possibly...your emergency brakes need attention?
but agreed with bluegrass with drive line inspection
or another COP going south, low grade miss-fire.
any codes present?

 

Dumb question - if it's throwing codes, would that be indicated by a "check engine" light?

 

Sometimes. I depends on if the PCM detects an issue with the control solenoids and circuits.
If it's a mechanical issue the OD lamp may flash or light when a function has a problem, then the CEL may not light.

 

My truck is having similar problems. I have an 02 Screw 5.4 4x4 that the tranny shudders like Im going over rumble strips when in or out of overdrive around 50-60. Doesn't matter if Im pulling anything now or not. I'm due for a transmission fluid change, but I'm afraid I have other damage. If anyone ever figures this out, PM me or email me.

 

I've had my tranny (actually the torque converter, or so I've heard) shudder, but has only done it a couple of times under severe sircumstances; very heavy trailer, taking off from a stand still on a grade. It was unmistakable in my scenario where it was coming from or what it was.

 

Could it be the horse trailer? I had a cargo trailer(2000 lbs) that made a god awful shudder throughout. Thought it was the transmission getting ready to go. I did some investigating on the trailer and found one of the bolts fell out of the leaf springs, causing a severe wheel hop.
If you can associate the noise\shudder with the trailer I would look there first. make sure all the tires are properly inflated and check to see if there is any mud caked into one of the trailer wheels.
Also, I would Check the fluid level and also smell/color of the fluid to see if it is burnt