PaulT,

If you had it serviced at one of those quick lube places, they probably didn't drain the Torque Converter. And yes you can add the 8oz bottle of friction modifier without draining any fluid. Don't have a part number, but most real autopart stores should carry it.

 

The Ford Dealership did the service, so hopefully they drained the torque converter as well. Do you recommend getting the friction reducer at the Ford dealer?

 

I had the same problem with my 2001 screw between 25 and 30 mph. Took it to the dealer, nothing. One day I realized that air was cavitating over the moonroof and causing a flutter throughout the cab. Crack a back window, and the problem was fixed. Might be too simple, but I thought I'd offer it up.


sblackb

 

I also have this problem with my truck and found it to be my tire out of round. I say the tire is out of round because it is worn more in one area than another. It is worn evenly across the tread but not all the way around. I have one tire with a lot of weight on it and this is the problem tire. The tire was on the front left and I started to get a vibration in the steering wheel, so I had them re-balanced and rotated. Now I have a hop in the rear of the truck at approx. 40mph just like you all describe and guess what, thats where the tire is now. I also can't get the tire dealer to do anything about this, my truck is already out of warranty.

 

sheen,

All five tires have been replaced on my truck, three specifically because they were out of round! The problem is still there. I am convinced it has nothing to do with the tires. Once the Goodyear GTII's are worn out, I plan on replacing them with the best set of Michelin LTX tires I can buy, and see if it helps any. I doubt it will, but at least they will wear well!

 

Ford dealerships carry "XL7 Friction Modifier" for ~$6.00. I plan on adding the XL7 today. I'll post the results.

 

I wish I would've found this thread about 50,000 miles ago! I have the same problem on my truck (2000 F150 ORP, extended cab, long bed) - vibration in the whole truck between 40 and 45 mph. I started right around 10,000 miles when I did my first tire rotation I and has done it ever since (now at 80,000 mi). Did it with the stock GY AT/S, the replacement AT/s because the original ones were determined to be out of round, and it has done on the Hoosier D/Ts. I got the same crap from both dealers and tire stores that I took it to. The agressive tread is causing it. I knew it was a load of crap but I couldn't get them to do anything about.


If the truck is hopping while accelerating, cruising, and coasting it's not the tranny. If only does it when it is acclerating, then it could be the tranny.