I'm not an Expy owner, but I've been through a class where they demonstarted the Hunter 9700 Road Force Balancer. Maybe some folks don't know what 'Road Force Balancing' is, so I'll try and give a brief explanation.

The wheel and tire assembly is mounted on the arbor of the computer controlled balancer. The first thing the machine does is effectively measure the distance from the arbor face to the inside wheel rim and the outside wheel rim, as this determines the wheel's offset, and stores the demension in the computer. (The amount of offset determines the distance a wheel weight is from the vertical centerline of the of the wheel and is used in calculating the amount of weight needed to balance the wheel dynamically.)

Next, the machine hydraulically applys a roller against the tire tread with roughly 1400 lbs of force while it rotates the wheel and tire assembly very slowly through two revolutions. This simulates a "road force" and is used to "feel" any 'soft' and/or 'hard' areas in the tire sidewalls. These soft and hard spots are measured in the thousandths of an inch of tread deflection by the hydraulically applied roller. The computer then creates a 'map' of the tire tread deflection around the tire's circumference.

Then the tech holds two rollers against the wheel, one against the inside (backside) edge of the wheel rim and one against the outside edge of the wheel rim, while the balancer slowly rotates the tire and wheel assembly. From this the computer maps the lateral and radial runout of the wheel's rim in thousandths of an inch.

From these two maps, the computer determines the optimum position of the tire on the rim to minimize 2nd and 3rd level harmonics. It will determine if this tire and rim can or cannot be brought into spec, and if it can be brought within spec, it will rotate the tire and wheel assembly so the tech can mark the spot on the wheel that should be aligned with a spot on the tire. Then the tech has to break down the bead and rotate the tire on the wheel to align the two marks.

After re-seating the bead, the tech remounts the tire and wheel assembly back on the balancer's arbor, and the computer proceeds to balance the wheel and tire assembly by spinning the tire at high speed and calculating the amount of weight needed and where it should be placed.

This is an awsome piece of equipment - and I have no connection to Hunter - I just happened to be taking an auto tech class where they had Hunter come in and demo the correct way to balance tires and wheels in this day and age.

 

Sounds good. I would love to see it work and have both my cars on it.

 

Great description of "road force balancing".

When the tire shop did this on my Toyos, they found one wheel (not tire) that was just barely within specs for run-out. Pretty impressive equipment for sure!

 

That is the exact same piece of equipment that my Ford dealer used to balance my expys tires since I too was experiencing the vibration problem. In fact, if you go to the Hunter website you can do a search to see what automotive shops have this balancer in your area. Not had any vibration problems since then (replaced two tires though)

 

I posted this on another thread/ Works here too

I just got back from the dealership with my 2003 Expy XLT. I developed a slight shimmy in the steering wheel while on the hway. My problem started when I was making turns, especially going onto or off ramps to hways. The back right rear end always seemed to want to slide out or fishtail on me. Went to the dealer and he said thewere way out of balance. They balanced and rotated the tires. I thought everything was going OK until I got on the hway and got up to 75 mph. The vibration was bad enough to make my forearm muscle shake. I took it back to the dealer and he said he couldn't do anything since he couldn't go over the speed limit. He recommended I contact Ford. Called customer service and basically got the run around. Cust service said that were going to send the problem to the engineering dept. and the Ford dealership I was at. I went through the problem with the Firestones on my 99 Explorer. This was the last chance for Ford. This al started with only 10K miles. It only has 11K miles on it now. I've owned mostly Fords since my 64 T-Bird convertible. I'm actually sorry I didn't buy the Sequoia. Here's my list of problems so far. Anyone comes up with a fix please let me know.

Clutch pack in rear axle replaced due to vibration on turns
Door cladding replaced due to rattling on doors
Whine at 42 MPH - Won't even try to get this addressed until the front is fixed
Brake dust - had to buy the Klean wheels so the car won't look like crap

 

That's a croc of BS! Tell them you're moving here to OK. Our speed limit (in some areas) is 75mph.

 

question:

When you all say that you have had the aligment checked/fixed, is it covered under warranty? I also have the shimmy when driving at a high speed, I also feel it when braking (but not in the brakes, just in the steering wheel.)
~Ammie

 

I have it ballanced twice, rotated, alighned and then finally the road force ballance, all under warranty.

It still has a little shimmy btw, but too little to complain about.

 

Fwiw, my C-model '03 stays absolutely wobble-free with the Conti's up to 80+. I run them at 43 psi.

 

Well, here's the settlement. The dealer insisted that it was two slightly cupped BACK tires causing the FRONT end shimmie on the vehicle. They indicated that this was due to a lack of tire rotation until 12K miles. I have a '96 Explorer with BADLY cupped rears and have NO shimmie in the steering wheel (yes it vibrates a bit, but the wheel doesn't shake in my hand!)

So I have a bet with my service manager. I asked to have my full size spare mounted and balanced, along with a NEW tire at their COST. I paid $101 for a new tire. If the truck remains "wobble-free" fopr 5K miles, I buy the tire. If not he does and we continue. He insists that the problem is due to lack of rotation. I'd just like to know if a tire will wobble at 10K on the front, how moving it to the back for 5K and then up to the front again will solve the issue which Ford is unwilling to admit??? There is a bigger problem here! So far 1K miles with no trouble.

My Step-dad has a new Explorere with the same issue. I beleive the rack is the same on both vehicles with loger tie rods on the Expy. What's the deal???

 

I've got an appointment to take mine back to the dealer I bought it from on Monday. They actually tried to tell me its my fault the tires are feathered since I didn't rotate them at 5K miles. I have 11K on the truck now. They changed their tune when I found a receipt for an oil change and tire rotation at 8k. Well within the recommended interval. I can't believe how bad Fords service has gotten. Even with the Firestone fiasco on my explorer, I didn't have to put up with this much crap.

 

In addition to the more typical out-of-balance tire condition that causes steering wheel vibration, I have also experienced problems with "cupping" of the Goodyear RT/S tires that originally came with my 2000 EB 4x4. Re-balancing didn't help this at all. The cupping developed at something like 40,000 or 45,000 miles. The visual symptom of a cupped tire is uneven wear around the circumference of the tire, OR, seeing different wear between the front and rear ends of individual tread blocks on the tire. (In other words, each tread block is worn at an angle, rather than being flat on top.)

In the Tire Rack's "buyer review" section, I've seen many complaints of cupping on Goodyear RT/S tires, admittedly when they have a fair amount of miles on them. Frequent rotation in an X-pattern serves to limit the amount of cupping, and to even out the wear, to some exptent. I just lived with it until the tires were worn to the point of replacement - putting some new Bridgestone Dualer AT Revos on solved the problem for good.

My son's Escape had Conti's on it - they seemed to drive OK, but were very noisy, and also were worn out at only 35,000 miles. He is very satisfied with a set of Firestone Destination LE's, which are an improvement in every way.

Bob Schleicher
2000 Eddie Bauer 4x4, 80,000 miles

 

Just got mine back; they replaced on tire due to broken belt, and road force balanced them. Not perfect, but have to admit about 95% better. Curious now to see how long the balance holds up, and if I am going to have to pay to have them road force balanced for the life of these tires.

 

Just got the truck back. They said a gear in the rear end was causing the shimmy. BS but the gear replacement and the other parts cured the 40+mph whine. Seriously considering Ford arbitration since they either won't address or can't correct the shimmy. Truck only has 12K on it now but I can't imagine how bad it will get with real mileage on it