I drive a 1997 Ford Aerostar XLT that’s just shy of 186K miles. In February, I had the rear differential gears replaced, and last month, I got 4 new tires. Just last week, it was in for oil change/brake check/routine maintenance. I’ve been pretty diligent about having my oil changed every 5000 miles, and my mileage hovers around 23-25MPG, which tells me my engine and transmission are doing OK.
In the last few weeks, I’ve noticed that when driving under 20MPH, the van shakes. The best way I can describe it is that it’s wagging its butt. I’m not feeling any shimmy in the steering wheel, and the speed of the rocking varies with the speed of the car. Above 20, either it stops or it’s just not as evident.
What could it be?
I don’t think it’s the front end. My husband thinks it might be tires out of balance. He doesn’t think it’s a wheel bearing issue. I can’t imagine what in the suspension might cause it.
I will be taking it in to be looked at once my husband’s car gets back from its timing belt change (cha-ching!!) I’d be interested in anyone else’s opinion of what may be wrong. I’m trying to keep this van running for at least 2 more years - that’s when our other car is paid off. I’d really like it to keep going longer without having repairs run the equivalent of a car payment.
So, whaddya think? Am I looking at needing a second mortgage to fix it? Am I driving a deathtrap? Could it just be unbalanced wheels? Gimme your best guess!
…Oh yeah, a 1997 Ford Aerostar XLT. When it shimmies, or wags its butt, I usually find one or more of the rear tires has low pressure. For some reason it’s difficult to tell a low tire on this van just by looking. Airing the offending tire usually solves the problem.
YMMV (mine sure does… I’ve never gotten above 21 mpg on mine.)
I too think it’s something with the tires, considering you did them last month, and 3 weeks ago it started shaking. In this case, it seems to add up. If not that, maybe the driveshaft is out of balance, or in need of repair (U-joint replacement).
I don’t think it is balance. That ususally shows up at a higher speed.
I can understand air pressure, or lug nuts, or they did not get one of the wheels mounted on the hub square.
With the miles on the car, I think you might also have an issue with a bushing int he rear suspension going bad, and allowing the rear axle to walk around a bit. This would give you the feel of the tail wagging the dog.
Well, I took it back to the tire place - they said all the tires were balanced. One guy drove it, and didn’t notice anything. He asked me to drive him around. I didn’t notice anything either. So maybe it was a matter of a wheel not being installed correctly. But I drove around a while after going to the shop, and it was fine.
The guy did suggest it could be a shock, since mine are originals. Is 186K too many miles on shocks? The van has been used to haul loads as well as for my daily commute over the course of its life.
Whatever. It seems to be fine. I’ll just monitor it and see what happens.
You shoud know that bad shocks, or suspension problems, can be dangerous, especially if you have to swerve or break hard. You van has a higher center of gravity and bad shocks will increase it’s tendency to roll in a sideways slide situation. As I mentioned above, you will notice an improvement in ride and handling when you replace them. I’d guess that some oother dopers can advise you on the best type and brand of shock for you van, if you intend to get new ones.
After 186K, it’s a wonder you still have shocks. Replace them right away. The Aerostar (my brother calls them “Deathstar”) has a bit of a problem with crosswinds, and new shocks ought to help. My brother’s company Deathstar was pushed across 3 lanes into a guard rail by a crosswind.
