After reviewing 337 posts earlier today under a search for "vibration & trac," I have come to the conclusion that I am an idiot. I have read post after post regarding things to check as the possible cause of the vibrations I'm experiencing, but I don't know where to start. Could someone please break down the process for a moron in order to make my challenge a little easier...I would greatly appreciate it.

Here's my situation: I have a 2003 SportTrac, V6 4L SOHC 4X4. When riding in the vehicle I can feel my butt shaking in the seat and my fee shaking on the floorboard. When it becomes really noticable, I started putting both hands on the steering wheel and I can feel a vibration there as well. Now, this is not a "violent shake" as many have described in other posts. However, you can definitely feel something and my wife, who accompanied me on a trip to Lexington, Ky, yesterday, said she could feel vibrations in the passenger seat as well. She did state that the vibrations were less noticeable when she had her feet up on the seat and off the floor board.

Sometimes, it seems that the vibrations correspond with the road surface. Could this be the case? There are some points during travel where the truck rides smoothly, and then all of a sudden, the vibrations are back. I'm just worried that it is the start of a much bigger issue. Further, when going over a larger bump, I can hear a "squeak" in the rear end as the truck bounces (shocks??).

To this point, I have had the tires rotated and balanced. Three of the four tire were slightly out-of-balance, but the vibrations were the same afterward. Also, I made sure the air pressure corresponded to Ford's recommendation (30 in front, 35 in rear) since all of the tires were filled to 35 psi.

Could someone tell me the next logically step for things that I can check before taking it to the shop. Or, in the alternative, if what I am experiencing is normal for my SportTrac. I have never driven a SportTrac prior to this one, but I have read where the suspension is 40% stiffer than that of an Explorer.

Thanks

 

Any vibration such as what you describe is not normal! There is something in the drivetrain causing vibration. Rear axle, drive shaft, tranny, gear box, motor...and since it is a 4x4, there is also a front axle too. Even though it's not engaged it could be causing vibration.

Try to narrow down what makes it worse, or better. Does it change with the RPM's or MPH? Cornering? Backing up? Slowing down? Hard accelleration or under load? Info like that will help a shop locate the problem alot faster. If it changes wwith RPM's its in the motor or tranny. If it changes with MPH, its past the tranny. Check the tires for uneven wear. Does it steer straight? It could be seriously out of alignment. I would also check the driveshaft too. (Honestly, I've never even looked under my Sport Track to see if it has CV joints or U-joints).

Just a few ideas. Good luck with it.

 

Thanks for the reply Sam. I crawled under the truck last night and tugged around on the axles, driveshaft, shocks, etc., and I couldn't find any play. I do know, however, that I am in need of an alignment due to the truck pulling to the left. I have to keep the steering wheel just right of center at all times in order drive in a straight line. Also, I haven't noticed a change in the vibration with MPH or RPM. I drive to work every morning on a two-lane state route in Ohio with heavy commercial traffic, so you can imagine the condition of the road -- lots of cracks on a worn-down surface. The vibrations I feel on this road while traveling 35 mph are very similar to vibrations I feel on the interstate traveling 65+MPH.

Sometimes while I'm feeling the vibrations and have to depress the brake, I feel a more prominent shudder in the rear end when the truck begins to slow down. Could this mean a problem with the rear rotors/rims/brakes?

 

I currently have an '03 with no vibration but my '99 had a seat of the pants vibration at all speeds that I or Ford never could find. Unfortunately the virbration you describe could be many things, out of round tires, a slightly bent wheel, out of balance drive shaft, broken motor or transmission mount, etc. etc. etc.

 

Thanks for the Reply z28dug. So, if I'm understanding you and Sam correctly, proper testing procedure may be: 1) alignment and tire balancing (where tech would check for bent rim, out-of-round, etc.); 2) check axles and driveshaft; 3) motor and transmission mounts. If not fixed, start looking for other possible causes.

Also, I forgot to mention that I tried dropping the truck in neutral last night when I was experiencing some minor vibration, and while in neutral, the vibration continued. I don't know what this means, if anything, but I read where someone had suggested doing this in a previous thread. Does this shed any light on the problem?