Car Information:
Ford Super Crew
Year: 2004
Engine Size: 5.4L
Trans: Automatic

Issue / Question:
I missed a transmission service @ 90k miles and started experiencing chugging between gears at 1500 rpm at 45 mph. At about 125k miles I got the super duper transmission service and the chugging is still there. Is there a way to tell if I need a new transmission or could it be something else? Please let me know.
Thanks

Answer:
What your describing is the transmission is going into 4th gear or torque converter lock up at too low of an RPM causing a chugging sensation! Alright if this is the case 4R70-W transmission I would scan the computer system first to make sure the vehicle speed sensor, the data being sent to the computer is correct, and if there are no codes I would be inclined to reprogram your computer if necessary, shift later by 5 to 7 miles an hour. I can check there might be an update on this if not we can program a different tire size to change the shift pattern, bottom line is if its a shift timing problem we should be able to save the transmission however if its slipping already it may be to late to save it, a test drive will let us know what to do. Let us know if we can help.

Update:
Owner: I bought larger tires at about 90k miles. I was told they are 2” larger diameter than the stock tires. I don’t know that I would say its slipping because when I accelerate and go through the gears at over 2000 rpm there is no chugging. Please let me know how long you think it would take it would take to evaluate the computer/sensor and adjust if that is what it needs and I will schedule accordingly.

Larry: 2 inches taller of a tire is like going from a 3.75 gear ratio to around a 3.50 gear ratio this can make a huge difference especially if the computer has not been re calibrated for the tire size difference, our NGS system can reprogram your computer to make adjustments based on your current tire size, I suggest doing this before anything else, give us a call and my guys will let you know the best time to bring it in<.

For professional Orlando Auto Repair you can call our shop today at 407-629-2661.

 

Magic Mechanic
1432 Lee Road OrlandoFL32804 USA 
 • (407) 298-7447