I got a screw in my tire on the edge so it couldn't be patched, I ended up just buying some cheap tracker 2 tires to last me until the front tires need to be replaced. I bought them and had them installed at wal-mart and immidately after, on the way home (or maybe the next morning) my expedition developed a problem. While driving at speeds 35 or higher, the truck will occationally vibrate, the steering will lock slightly (not enough to be a safty issue) and just at the end of the occurance the car will turn left slightly. This happens on regular intervals, give or take a few minutes. I'm about to go and switch the tires left to right to see if it will turn slightly right.

I bought this expedition used a few weeks ago, but i've NEVER had this problem, so i'm pretty sure that wal-mart did something wrong, but neigther I nor they can figure it out. any suggestions would be great.

thanks

 

most likely a bad balance job or the tire is just bad

 

update:

i just flipped the tires and there wasn't a change.

What I did notice is that the front right tire (which is where the car drifts towards) is very chopped up with pieces taken out of it, and the front left tire is perfectly smooth. I'm not sure why this is, but a friend of mine says that I need a new ball joint and control bushing (i don't know what that means). so I'm pretty sure that the problem is with the front right tire.

thanks for any help

 

What year is your Expy? Do you have the 2wd mode or just 4auto? If you don't have the actual 2wd mode ('03 +), then I can probably explain what is happening. The auto 4wd drive system uses speed sensors on both the front and rear output shafts of the transfer case to detect differences in speed between the front and rear. If proper conditions are met, the computer kicks in the transfer case. Because you have new tires on the rear, and older tires on the front (having different diameters due to wear, and also because they are probably different tires all together) under certain driving conditions, the sensors will report axle speeds that are different enough to momentarily kick in the 4wd. It may even rapidly engage & disengage repeatedly, resulting in it "chattering", or vibrating. This can damage your 4wd system. The stiffness in the steering is probably due to the front drive wheels engaging, or you could also have a bad u-joint in your front axle.

What to do about it? Try putting both new tires on one side of the truck, and both older tires on the other side. This puts the diameter difference side to side, instead of front to rear, and fakes the system out as long as the difference isn't too drastic. If all seems normal when you drive it, you are probably O.K. til you get new tires - just keep an eye (ear?) out for any issues! This is why they recommend replacing all 4 tires at the same time!

Your "chopped up", or maybe "cupped" tire is most likely unrelated to this problem in any way other than possibly contributing to the vibration that you feel!

Hope this helps!
Steve

 

Steve: on the pre-'03s -- I thought they were viscous couplers for front and rear torque splitting? It still could, in theory, be an issue if the diameter diff. was big enough...

I'm surprised you could get cupping that quickly, or with that little use?

 

I think (correct me if i am wrong!) the cupped tire was one of the tires that weren't replaced, and was already like that! Probably a worn part/alignment issue!

To the best of my knowledge none of the Borg-Warner TOD cases use a viscous coupler. The AWD in the 5.0 V8 Explorer/Mountaineer do use a viscous coupler, however. I do remember a 2wd mode in at least some of the '97 & '98 models, but if yours doesn't have 2wd mode you can also pull the fuse to eliminate the problem temporarily, but of course you won't have 4wd!

Steve

 

Thanks for straightening me out on the transfer case/AWD -- learn something new every day... And you were right on his fronts being the olds ones -- god that backwards as well...

 

Fixed. I think that I agree with Jetski. Before reading this my initional idea was that since the rear tires were newer and had thicker tread and the front left tire was slightly thicker than the front right, the truck was wobbleing like a three legged dog. I didn't think about the AWD engaging, but it makes sense.

I went ahead and bought the same tires for the front and did some heavy driving for a few hours and the problem is GONE. the last issue that I have left is that I am thinking of getting the tires aligned, but i'm hoping it can be cut out due to the 95 dollar expense.

2000 ford expedition 4wd

ps could someone warn me of any serious issues that are down the road, its 101000 miles

 

With the cupped tire you mentioned and the fact that you're at 101K, it's a good bet that your lower ball joint and maybe tie rod end are shot on that side. If so, best to replace both sides before you wear out your new tires. At a miminum, I would have it aligned - an honest alignment shop will show you if anything is worn in the front end.