[updated:LAST EDITED ON 05-Aug-02 AT 09:23 AM (EST)]New owner of a 2002 f-250 powerstroke 4x4 short bed crew cab.
Have driven several, but this is the first one I have owned. It is one week old and at 40-50 miles per hour, I notice a resonant vibration. When you accelerate it seems to lessen. It has factory all terrain tires and an automatic trans. Is this a characteristic of the diesel, tires, or a possible prelude to a transmission failure? I would rather ask the question before going through the warranty ordeal with the dealer. I would rather be informed than waste time trying to explain the situation to the dealer. This vibration is different than that of a torque converter failure, since I went through that with my old f-250 460 automatic.

 

Before doing anything else, check the drive shaft bolts. That is the first thing to check on the truck. Next would be tires. Then and only then if nothing is found, go have a battle with the dealership. The most usual cause of vibration is of course the tires, but the driveshaft can cause it too. Often in that case, the bolts are loose or missing, sometimes the tube is out of balance. That is a problem I had with my truck for a while. It still does not like to go over 85.



Wm
'96 F450 White with Grey interior Crew Cab. Banks Turbo, Intercooler and Exhaust,
Power pack Chip, shift kit, Auxiliary transmission, electronic enhanced transmission control,
16 forward and 4 reverse ratios. 340hp 660ft lb 4 wheel drive, 4.10 gears, 12,ooo# winch

 

79CEEJAY, there was a similar question posted last week. If your vibration is "resonant" then my post, pasted below, may help. At any rate, I am a vibration analyst and trouble shooter for a major OEM of industrial equipment. I travel nationally and internationally trouble shooting vibration problems in power plants, cement plants, AUTO ASSEMBLY Plants, AUTO Engine PLants, paper mills, mines and general industry. If it rotates I have seen problems with it somewhere. Twenty years of expenience has taught me that 80% of machine vibration is in three categories, imbalance component alignment and mechanical loosness. Or some combination of the three. A very short list and it covers 8 out of 10 problems. One good thing about it these three are ususally the cheapest and easiest to solve.

" Dan, the vibration starts at 50 and goes away at 55? Usually when this happens it's an unbalanced tire. It works like this: a point of imbalance can only go around once per revolution, giving it a difinitive frequency 1 X RPM of the tire. At a given speed the unbalance (centrifugal force) at 1 X RPM equals the net natural frequency of a system of parts, usually the front end steering system. The source force of the imbalance excites a system at it's net natural frequency, resonance then multiplies the source 10 to 50 times. Speed up or slow down the vibration ususlly goes away because you are changing the input frequency away from the natural frequency, usually plus or minus 20% will do. Ever shut down a light weight high speed machine and listen to the coast down and the the peak vibrations as it coasts down? Those peaks are natural frequencies. The possible solutions, stiffing the systems parts and raise the first natural frequency of the part or lower the input force. Usually lowering the input, balancing the tire or shaft, is more practicable than stiffining the front end or drive train. When this phenonomenom is noted the natural frequency of the system can be changed by load which can be carried bed load of fuel status. That can change the speed at which the problem is noted but the basic cause is the same.
First, check all points of potential loosness as had been suggested above. Mechanical loosness can also act as a force multiplier of sorts. Then rotate and balance your tires, if you are like me that is always over due. If the vibration remains it is most likely the drive shaft. That is the short list, the rare but possible list is much longer and involved"

Best regards

 

I'll check driveline bolts first. My tire dealer, who also supplies tires for our large trucks, calls me "The Princess and the Pea" because I am so critical of vibrations. I can usually pinpoint a tire imbalance within 1/2 oz. The truck only has 300 miles on it. I suspect it may be a vibration of the tires, since they are open lug all terrains. Appreciate the advice......I'll post my results.....

 

After i put big tires on the back of my PSD it started doing that so i had them to rebalance them and it stopped.