Truck and Trailer Question

Originally written by Rose66 on 2009-10-23 6:02 PM

Originally written by Paul D on 2009-10-23 7:49 AM

Rose,

What is probably happening is the electronic controls that lock your transmissions torque converter into a direct drive type of connection are going on/off rapidly which causes the jerking sensation you are experiencing. This problem can be caused by several different conditions. One of those conditions is the rear anti-lock brakes. This is something that is not apparent to most people and some technicans included. The rear axle sends a signal to the anti-lock brake controller that must match up with the signals from the front wheels. When the signals don't match the anti-lock brake controller sends a signal to the transmission controller that unlocks the locking torque converter. When this happens under normal circumstances you never feel anything. When the transmission controller receives inconsistant signals the locking torque converter is going on/off which can cause the jerking you are feeling while under load but when you release the accelerator the condition disappears because no load is being applied to the torque converter.

However in your case the problem could be caused by the solenoid (or whatever they want to call it) in the transmission that actually locks the torque converter. These do go bad and they can cause the jerking you are experiencing or if they stick in the on position when you come to a stop sign and apply the brakes you will kill the engine. Some repair shops would rebuild your transmission and send you on your way. I personally would only replace the defective solenoid and see if that fixes the problem.

Paul, I don't know much about trucks but what you describe actually makes sense and sounds likely. I'm going to print out your post and show it to the Ford dealership to see what they say. If it were my solenoid in my transmission going bad, is it common for them to go bad in less than 10,000 miles? Or could there be something else wrong that made the solenoid go bad? Thanks!

Rose, I have been dealing with these type trucks for some years now and the first thing you will notice if the problem is what Paul has talked about is the OD or TOW/HAUL light will flash on and off and or your abs light will come on as well. You can confirm this with 99% of the folks that works on Ford stuff. Yes, these solenoids in the transmission do work along with the abs sensors like Paul said. But this is something you would notice unloaded also, not just when you had a trailer hooked up.

So please do not go spend good money after bad on the transmission again. Go see Don and pull a couple of trailers and I think you will find that you might need to add some type of rear helper springs, air bags or even try the hitch deal.