My van just got back from the shop after an alignment. I asked for a four wheel alignment but they said that was not possible on an Aerostar. My Aero goes down the road slightly "crabbed" as I call it or "dog tracking" as they called it..... meaning that when I follow it I can visually see that it going slightly sideways down the road.

My question is, can the rear wheels be aligned on a 97 AWD Aerostar? How?

They essentially said they would do it if I could prove it can be done. Not cool of course, but I've already paid for it.

Thanks!

 

The rear lower control arms have front pivot bolts that have cam washers on them. In theory, they can be adjusted to slightly move each side of the rear axle forward or backward, which can allow you to change its thrust angle. I don't know why the shop did not want to do that.

 

Ah ha, thanks xlt4wd90!

That is exactly what I thought looking at the rear. You can see that the bolt head is not centered on the leading end of the rear trailing arm. I even showed them that before I took it home tonight but they still weren't convinced because their system (alldata I believe) does not have alignment specs for the rear.

Has anyone had an alignment shop do a rear / four wheel alignment on their Aerostar?

 

Now that I know that "Dog tracking" is the universally accepted description of what my van is doing, the forum's search function has become more helpful

This is a good related thread: https://www.ford-trucks.com/forums/6...ajustment.html

Repost of "TheHandyman":

"the rear pivot bolts go thru cam type washers. flat washers with offset holes. the washers are tack welded in place once the axle is mis-aligned at the factory. Yeah, i meant to say that!

This can be checked and corrected with simple tools. Use a tape measure to measure back to the axle centerline from a couple consistent chassis points beneath the car. Try measuring back from a frame corner that is the same on both left and right sides underneath. Also you can use holes that are same left and right under there. Try the transmission crossmember mounting points. It doesnt take long to identify the problem. The adjusting washer(s) will need to be chiseled loose from the frame in order to adjust the axle position. Then the axle shifted, bolt tightened and measurements re-checked. Do this until you get it as perfect as you can.

I've driven and seen too many Aeros pulling and wandering down the roads. My low mileage '94 apparently came from the factory with the passenger side of the rear axle 1/4" further forward than the driver's side! 1/8" is the maximum that wheelbase should vary from side to side.

I've driven other '94s recently with the same identical pulling problem. If Ford used a jig, then that was off. Regardless no one bothered to check it or correct it. Who knows how many thousands went out the door like that. Even if it's caused by the fat soft bushings they could have compensated for it if they'd caught the problem."

 

Boy, I can't believe I said the exact same words about 2 years ago.

Has your van alway dog-tracked, or was it a recent occurrence? If recent, there might have been some event, such as hitting a curb, or chained down onto a flat bed truck by the control arms, that caused the problem. That should be checked out and fixed if necessary.

 

Thanks for you help!

I've had the van for three years and it has always "dog tracked". Now that I know those washers are tack welded I'm guessing my local shop will continue to respond with " the rear can't be aligned "... and so they aren't going to help me (which bothers me because I've already spent $90 for an alignment (for which they only did the front). I think I'm going to have to try and do the rear myself.

I just finished putting in new upper/lower ball joints, inner/outter tie-rod ends, and upper control arm bushings (I did these things) followed by a front end alignment. Now that the front is solid I hope I can get it to go straight down the road!

 

A good alignment shop will check all four wheels and should provide you with a print out of the spec sheet. This will show you the factory range settings, the before alignment figures for each wheel and the after alignment settings. They usually will go over the sheet with you and point out where the problem areas were and what was done to correct the problem.

There is a finite range of adjustment possible on the rear suspension. Sometimes, if there has been significant wear to the suspension bushings or minor damage to the suspension links, there will not be enough adjustment range possible to bring everything back in alignment.

I am of the opinion the Aerostar offers an optical illusion when view from the rear going down the road. I have followed my wife on occasion and thought I saw slight crabbing. A trip to the alignment shop always says otherwise as all geometry is within spec. Part of this illusion is the fact that the rear wheel track line is wider by approx 1 inch than the front track line - by design. If you were behind the van and trying to view both lines in a straight line it would impart a sense of slight crabbing as you would actually be viewing the track lines at a slight angle to compensate for this offset.

 

I noticed they didn't have any specs for the rear the first time. I just got the van back after they had a second look. As I assumed they didn't align the rear but at least the spec sheet now has numbers for the rear. Apparently they didn't have factory alignment specs for the rear (only the front) so I'm not sure how much their readings for the rear helped... They did readjust the front and the specs for the front are now different then they were the first time they did the alignment (both times they were within range though).

Thanks for the tip. Knowing this, I'm going to follow my wife again and see if this is the case.

After the second alignment, my steering wheel is now perfectly centered.. which it wasn't before. It used to be slightly off center and pointing in the direction (right) that would be needed to compensate for the direction it was "dog tracking". So I'm curious if, when they aligned it the second time and took measurements from the rear wheels they adjusted the front and were somehow able to correct the "dog tracking" ?? I guess I'll know when I follow the van next time.